Search

BACKGROUND: In clinical practice, knee flexion at the prone position for manual muscle testing of hamstrings and hip extension at the supine position for stretching of hamstring muscles are typically proposed. OBJECTIVE: Although different positions have been proposed for different purposes in hamstrings, the understanding of the changing the functional role of hamstrings with position changes is poorly understood. METHODS: The electromyographic (EMG) activity and hip extension force were compared among different postures; hip neutral, internal, and external rotation. EMG and force were measured in prone position during knee flexion and those were additionally measured in supine position during hip extension. In supine position, additional measurements were made in hip neutral, internal and external rotation. RESULTS: Hamstrings showed high EMG activity during knee flexion. Knee flexion force in prone position was significantly decreased at hip extension force in supine position. In supine position, EMG activity was significantly higher in semitendinosus (ST) than biceps femoris (BF) during internal rotation. CONCLUSIONS: It should be noted that bi-articular muscles may have different functional dependencies on the corresponding muscles for each joint. In addition, because the altered alignment of the hamstring muscles that was affected by hip rotation had a significant effect on muscle activity, and hip rotation may be helpful for selective training of medial or lateral hamstrings.

Background The effect of change in hip anatomy on change in gait pattern is not well described in current literature. Therefore, our primary aim was to describe and quantify changes in hip geometry and gait pattern 1 year after total hip arthroplasty (THA) in individuals with hip osteoarthritis. Our secondary aim was to explore the effect of postoperative change in femoral neck anteversion (FNA) and femoral offset and acetabular offset (FO/AO) quota on postoperative change in hip rotation and hip adduction moment during gait, respectively, 1 year after THA”. Methods Sixty-five individuals with primary hip osteoarthritis, scheduled for THA, were analyzed in this prospective intervention study. Participants were evaluated pre- and 1 year postoperatively with computed tomography-scans, three-dimensional gait analysis, and patient-reported outcome measures. Multiple linear regressions were performed to evaluate the association between change in joint anatomy and change in gait pattern after THA. Results One year postoperatively, global offset was symmetrical between sides as a result of decreased acetabular offset and increased femoral offset on the operated side. Quality of overall gait pattern improved, and participants walked faster and with less trunk lean over the affected side. FNA and hip rotations during walking changed equally in external and internal directions after THA and change in hip rotation during walking was associated with change in FNA in the same direction. An increase in external hip adduction moments was, on the other hand, not associated with change in FO/AO quota but with a more upright walking position and increased walking speed. Conclusions The findings of this study suggest that geometrical restoration during THA impacts postoperative gait pattern and, in addition to known factors such as FO, height of hip rotation center, and leg length discrepancy, the FNA must also be taken into consideration. Trial registration Trial registration: Clinicaltrial.gov, NCT01512550, Registered 19 January 2012 - Retrospectively registered.

[Purpose] To investigate the difference by degrees in total hip rotation range of motion (ROM) between sides and with regard to gender in healthy young Japanese adults. [Participants and Methods] Data from previously published studies were used. We utilized the left and right hip rotation ROM of 205 Japanese participants aged 18 to 25 years, who satisfied the inclusion criteria and were randomly measured three times in the prone position by the double-blind method. The average value of the three measurements was used to calculate the left-right difference of the hip total rotation ROM in the hip joints, which is the sum of the hip internal and external rotation ROM. We investigated the distribution of the total hip rotation considering the flexibility factor and its relationship with gender. [Results] We confirmed that there were seven participants with 2 SD or more and two with 3 SD or more. No significant difference was found in the left-right difference in the total hip rotation ROM, regardless of gender. [Conclusion] The distribution of left-right differences in the total hip rotation ROM in healthy young adults showed the existence of a significant left-right difference of 2 SD or more.

Inaccuracy of ischiofemoral space (IFS) measurement may result in radiographic misdiagnosis of ischiofemoral impingement, as well as insufficient or excessive osseous resection when surgery is indicated. This study compared the IFS measured in magnetic resonance imaging (MRI) performed in distinct health services for the same patient. Sixty-five patients (95 hips) who had hip MRI performed at an outside institution (noncontrolled MRI) followed by a hip MRI with lower extremity positioning reproducing the standing position (controlled MRI) were studied. For each hip, the IFS measured in the noncontrolled MRI was compared to the IFS measured in the controlled MRI. The categorization of a hip as presenting decreased IFS (≤17 mm) or normal IFS (>17 mm) changed in 19% of the hips when comparing the noncontrolled MRI to the controlled MRI. From the 32 hips (34%) with a difference ≥4 mm in the IFS, the predominant positioning change was hip flexion/extension in 47%, hip rotation in 44%, and hip abduction/adduction in 9%. In conclusion, a difference >4 mm in the IFS was observed in 1 out of every 3 hips when comparing noncontrolled MRI with controlled MRI reproducing the lower limb positioning in the standing position.

OBJECTIVES Dynamic knee valgus is composed of hip-knee coupling. While females differ from males in passive hip motion, hip rotation range may alter muscle mechanics and neuromuscular activity. This study aimed to compare knee abduction biomechanics during double-legged drop-landing between males and females with different hip rotation ranges.METHODS This study included five females with the range of hip internal rotation (IR) > the range of hip external rotation (ER), five females with ER>IR, four males with IR>ER, and five males with ER>IR. There was no difference in other hip motions among them or no difference in hip muscle strength between the same sex groups. Three-dimensional motion analyses of the hip and knee joints were performed during double-legged drop-landing.RESULTS Multiple regression analysis of females with IR>ER showed that peak knee abduction moment (KAM) was associated with maximal hip abduction moment before detecting peak KAM whereas peak knee abduction angle (KAA) correlated with no variable. In females with ER>IR, peak KAM was associated with maximal hip ER moment before detecting peak KAM, hip ER muscle strength and hip adduction range while peak KAA correlated with peak hip abduction moment before detecting peak KAM. In males with IR>ER, peak KAM was associated with hip ER range and hip adductor strength whereas peak KAA correlated with maximal hip ER moment and maximal hip IR angle during landing. In males with ER>IR, peak KAM was associated with hip extensor strength, hip abduction range and hip flexion range whereas peak KAA correlated with hip ER moment before detecting peak KAM, hip ER muscle strength, and hip adduction range.CONCLUSIONS Hip rotation range may differentially affect hip-knee coupling strategy for knee abduction control during double-legged drop-landing between males and females.

BACKGROUND: Few studies have explored the relationship between muscle strength, range of motion (ROM), and balance in the horizontal plane of the hip joint using three-dimensional (3D) motion analysis. OBJECTIVE: We investigate the relationships of hip internal rotation (IR) and external rotation (ER) ROM, measured using a 3D motion capture system, with hip internal and external rotator strength and single-leg standing balance. METHODS: The participants were 40 healthy adults. Kinematic data on hip ROM were collected using an eight-camera motion analysis system. Hip rotational strength measurements were obtained using hand-held isometric dynamometry. A Single-leg standing test and a pendular test were conducted to evaluate static and dynamic balance ability using BioRescue. RESULTS: Significant correlations were found between hip strength and each variable measured during hip ROM assessments (p< 0.05). Significant positive correlations were found between the hip IR/ER strength ratio and the IR/ER ROM ratio (r= 0.72, p< 0.01). The subgroup with a normal IR/ER ratio of hip rotator strength and ROM showed significantly better dynamic balance ability than the subgroup with a hip rotator muscle imbalance (p< 0.05). CONCLUSIONS: There is a significant relationship between hip IR/ER strength and IR/ER ROM with a normal hip IR/ER strength and ROM ratio positively affecting dynamic balance ability.

To examine the effect of external hip rotation on ischiofemoral (IF) and quadratus femoris (QF) spaces using real-time kinematic MRI, with the hypothesis that hips with IF and QF space narrowing have distinct motion patterns compared with control hips. This prospective study was IRB-approved and complied with HIPAA guidelines. We recruited women (≥ 18 years) with and without ischiofemoral impingement to undergo kinematic MRI of the hips. A kinematic imaging protocol using T2-HASTE was performed beginning at maximal internal rotation followed by active external hip rotation. The duration of each acquisition was 30 s, providing 8 images/3 s. IF and QF spaces, and femoral metaphyseal and lesser trochanter centroid coordinates were measured on sequential images. Hips were classified as controls or narrowed based on IF and QF space thresholds and compared statistically throughout motion stages. The cohort comprised 12 women (24 hips; 10 control and 14 narrowed hips) aged 58 ± 10 years. External rotation caused IF space reduction of 59% in narrowed hips versus 41% in control hips. QF space decreased 71% in narrowed hips versus 50% in control hips. IF and QF spaces differed significantly between groups only when external rotation exceeded the neutral position (P

The clinical assessment of hip rotation range-of-motion (ROM) is important for managing hip and groin injuries in footballers. Previously published reliability studies on hip ROM have employed protocols that are difficult to replicate under everyday clinical conditions. This single trial, intra- and inter-rater reliability study included 41 male academy football (soccer) players, aged 14–15 years, from one European football academy. Passive hip internal rotation (IR) and external rotation (ER) ROM were measured in supine with hip and knee flexed to 90°. The ROM was determined using a smartphone application, with the smartphone attached to the lower leg. The tests were performed on two separate occasions, one week apart, by two different physiotherapists and on both sides (left and right hips). Reliability was evaluated using Intra-Class Correlation Coefficients (ICCs) and Minimal Detectable Change (MDC). Hip IR and ER ROM displayed moderate to good intra-rater agreement (ICCs 0.54–0.75), with MDCs ranging from 10.9° to 16.4°. Inter-rater reliability displayed poor to moderate reliability (ICCs 0.33–0.75), with MDCs ranging from 11.7° to 16.5°. A hip rotation ROM test using a smartphone application and a protocol closely reflecting everyday clinical conditions displayed moderate to good intra-rater reliability and poor to moderate inter-rater reliability. Due to the high MDCs, the practical applicability of this test procedure is limited and further refinement is necessary.

Robotic total hip arthroplasty (THA) improves accuracy in achieving the planned acetabular cup positioning compared to conventional manual THA. Robotic THA improves precision and reduces outliers in restoring the planned centre of hip rotation compared to conventional manual THA. Improved accuracy in restoring hip biomechanics and acetabular cup positioning in robotic THA have not translated to any differences in early functional outcomes, correction of leg-length discrepancy, or postoperative complications compared to conventional manual THA. Limitations of robotic THA include substantive installation costs, additional radiation exposure, steep learning curves for gaining surgical proficiency, and compatibility of the robotic technology with a limited number of implant designs. Further higher quality studies are required to compare differences in conventional versus robotic THA in relation to long-term functional outcomes, implant survivorship, time to revision surgery, and cost-effectiveness. Cite this article: EFORT Open Rev 2019;4:618-625. DOI: 10.1302/2058-5241.4.180088

Background: The complexity of femoral and acetabular anatomy and restoring anatomic center of hip rotation in Crowe type IV developmental dysplasia of the hip (DDH) complicates standard reconstruction. The aim of this study is to evaluate surgical techniques and clinical outcomes of subtrochanteric transverse shortening osteotomy with the use of cementless rectangular cross-section femoral implants in Crowe IV dysplastic hips. Methods: A total of 26 hips of 25 consecutive patients with Crowe type IV DDH who underwent cementless total hip arthroplasty with subtrochanteric femoral transverse shortening osteotomy were retrospectively analyzed. The Harris Hip Score, Visual Analog Scale-pain, leg length discrepancy, and vertical and lateral migration of hip rotation center were recorded. Results: Mean age, follow-up, and time of union were 41 ± 9.7 years, 7.1 ± 1.2 years, and 3.7 ± 1.1 months, respectively. Mean Harris Hip Score significantly improved from 38 ± 5.7 to 86 ± 6.1 points postoperatively (P < .01). Mean leg length discrepancy and Visual Analog Scale significantly decreased from 4.3 ± 1.3 to 1.2 ± 0.6 cm, and 6.4 ± 1.2 to 1.8 ± 0.8 points, respectively (P < .01). One female patient had a dislocation due to acetabular liner wear, which was managed by liner and head change. One patient had Sudeck’s atrophy, while another had pain on the lateral thigh, both of which were resolved with conservative management. Conclusions: Combined transverse subtrochanteric femoral osteotomy and cementless total hip arthroplasty with rectangular cross-section femoral implants is technically demanding, effective, and safe in femoral shortening for treatment of Crowe type IV DDH. Keywords: Subtrochanteric shortening, Crowe type IV dysplasia, Rectangular stem, Total hip arthroplasty

We aimed to evaluate whether there are differences in the rotation center, cup coverage, and biomechanical effects between conventional and anatomical technique. Computed tomography scans of 26 normal hips were used to simulate implantation of acetabular component. The hip rotation center and acetabular component coverage rate were calculated. Moreover, a finite element model of the hip joint was generated to simulate and evaluate the acetabular cup insertion. Micromotion and the peak stress distribution were used to quantify the biomechanical properties. The medial and superior shifts of the rotation center were 5.2 ± 1.8 mm and 1.6 ± 0.7 mm for the conventional reaming technique and 1.1 ± 1.5 mm and 0.8 ± 0.5 mm for anatomical technique, respectively. The acetabular component coverage rates for conventional reaming technique and anatomical technique were 86.8 ± 4% and 70.0 ± 7%, respectively. The micromotion of the cup with conventional reaming technique was greater than that with anatomical technique. The peak stress concentration was highest in the superior portion with conventional reaming technique, whereas with anatomical technique, there was no stress concentration. Paradoxically although the acetabular component coverage rate is larger with conventional reaming technique, anatomical technique provides less micromotion and stress concentration for initial cup stability. Thus, anatomical technique may be more suitable for acetabulum reaming during primary total hip arthroplasty.

BackgroundSome patients undergoing total hip arthroplasty (THA) show postoperative changes in hip rotation. We investigated changes in the hip rotation angles of patients in the standing position before and after THA and the factors associated with such changes.MethodsParticipants included 77 patients (82 joints) who underwent primary THA for hip osteoarthritis. There were 17 joints in men and 65 joints in women, and the mean age at the time of surgery was 65.7 years. Standing hip rotation angles and hip internal/external rotation ranges of motion (ROM) were measured before and 2 weeks after THA to compare preoperative and postoperative measurements. For radiographic measurements, acetabular and cup anteversion, neck and stem anteversion, combined anteversion (CA), and leg length discrepancy were measured before and after THA to investigate the factors associated with changes in standing hip rotation angles.ResultsRegarding standing hip rotation angles, external rotation was 6.9° ± 4.1° before THA and 2.0° ± 2.4° after THA, showing a shift in the internal rotation direction (P = < .0001). The degree of change in standing hip rotation angles before and after THA was found to be negatively correlated with the degree of change in cup anteversion (- 0.429, P = < .0001) and CA (- 0.3012, P = .0063).ConclusionPostoperative changes in standing hip rotation following THA were considered associated with extra-articular position sense, rather than intra-articular position sense, to maintain the balance between the pelvis and proximal femur affected by the angles of the placed implant components.

Background The increased incidence of lower extremity injury in runners compared to the general population is well documented. The amount of passive hip rotation and the position of hip flexion or extension at which it occurs may be factors related to injury incidence. Purpose The purpose of the current study was to measure and compare hip rotation passive range of motion in male and female runners and non-runners at 0 and 90 degrees (°) of hip flexion. Study design Descriptive Laboratory Study. Methods Eighteen Division II collegiate distance runners (9 female, 9 male, mean age = 19.1, +/- 1.1 years) who had run for an average of 7.1 (SD = 1.7) years participated in the study. Twenty non-runners (10 female, 10 male, mean age = 19.6, +/- 1.1 years) from the same institution were also recruited. Passive hip internal rotation (IR) and external rotation (ER) were measured with a universal goniometer in 90 ° of hip flexion in a seated position, and in 0 ° of hip flexion in prone position. Results There was a significant difference in IR measured in 0 ° of hip flexion, between runners and non-runners (F(1,37) = 8.04, p = .007). Additionally, the difference in IR between males (36.68 + /-9.19 degrees) and females (45.99 + /- 9.12) was significantly different (F(1,37) = 20.79, p = .001). There were no other statistically significant differences in measurements between groups. Conclusions Collegiate runners had significantly greater passive hip IR when measured at 0 ° of hip flexion compared to the non-runners. Female runners had significantly greater passive hip IR compared to the male participants across both runners and non-runners. Level of evidence 3.

Background: Alignment of the lower limb is an important factor, influencing balance and gait in kinematics and kinetics, in patients with and without a flat arched foot. Flat arched foot are associated with the range of motion (ROM) of the hip and alignments of the knee joints, is strongly influenced.Objects: The purpose of this research was to investigate the relationship between hip joint ROM and quadriceps angle (Q-angle), by dividing them into two groups according to the presence or absence of flat feet, using a navicular drop test (NDT) and resting calcaneal stance position (RCSP).Methods: Forty elderly patients were allocated to the experimental group (flat foot group, n1=20) or the control group (non-flat group, n2=20). Universal and digital goniometer, tractograph and tape measure were used to determine the related changes in the hip ROM, Q-angle, NDT and RCSP.joint (right, r=.803, p

The purpose of this study was to investigate the characteristics of biomechanical and clinical measurements in relation to the knee adduction moment when wearing a standard shoe and a shoe design for individuals with knee osteoarthritis (Flex-OA). Kinematic and kinetic data were collected from thirty-two healthy individuals (64 knees) using a ten camera motion analysis system and four force plates. Subjects performed 5 walking trials under the two conditions and the magnitude of individuals' biomechanical responses where explored in relation to the clinical assessment of the Foot Posture Index, hip rotation range, strength of hip rotators, and active ankle-foot motion, all of which have been described as possible compensation mechanisms in knee osteoarthritis. Significant reductions in the first peak of the knee adduction moment (KAM) during stance phase (9.3%) were recorded (p

Reduced lead hip mobility has been proposed to be associated with low back pain (LBP) in golfing populations, although the literature is contradictory. This study aimed to clarify this relationship by recording the magnitude of hip rotation during the golf swing and a range of clinical assessments. Sixteen recreational male golfers (8 with a history of LBP and 8 age and anthropometrically matched controls) performed their golf drive with their hip movement recorded. Hip range of motion was also recorded in sitting, lying prone and standing and correlated to hip rotation during the golf drive. The LBP group demonstrated reduced lead hip internal rotation (LHIR) compared to those in the no pain (NP) group when using the prone passive and standing clinical measures (*p* \< .01), but not sitting. The prone passive measure of LHIR was moderate-strongly correlated to golf swing LHIR r = 0.560; *p* = .024. The LBP group had an average of 8° less LHIR during the golf swing than the NP group and were closer to end or range, although both were non-significant trends. These results may have implications for LBP prevention and rehabilitation strategies in golf populations.

BACKGROUND AND AIM Hip and knee OA has been ranked as eleventh maximum contributor to global incapacity. The prevalence is expected to increase up to 25.9% by 2040. Hip arthritis reduces the mobility at the hip joint limiting flexion extension, abduction, and adduction, internal and external rotation. Similarly knee pain causes considerable disability among middle adult population affecting both proximal and distal joint (hip and ankle) respectively. Hence the present study aims to find out a correlation between Hip Rotation Dysfunction and Knee Pain METHODOLOGY A cross sectional study was conducted on patient with hip and knee pain of age in between 45 to 60 years. Ranges at the level of hip joints were assessed using goniometer. Knee pain was assessed using Visual Analog Scale. RESULT The result obtained from the study shows a moderate negative correlation between knee pain and hip internal rotation, r= -0.67 showing no significant correlation p=0.45. There is also a weak negative correlation between knee pain and hip external rotation, r= -0.37 with a p> 0.05. CONCLUSION The result obtained from the study concluded that no significant co-relationship exist between hip rotation dysfunction and knee pain, however more researches with larger number of sample size is required to further evaluate the causal relationship between the two variables.

Purpose:In developmental dysplasia of the hip (DDH), the centers of hip rotation move in the superior and lateral direction. In total hip arthroplasty for such cases, movement of the center of hip rotation is in the inferior and medial direction. It causes an increase in leg length and a decrease in acetabular offset. We therefore evaluated the change of hip offset and leg length before and after surgery with two stems having a high offset option.Patients and Methods:The preoperative diagnosis was secondary osteoarthritis due to DDH excluded Crowe IV. A stem selection was decided based on preoperative two-dimensional templating. Total 55 hips in 50 patients were followed up for minimum 10 years. Pre- and postoperative clinical evaluations were performed using a hip joint function scoring system. Radiographic evaluations were used for offset and leg length measurements and other associated factors.Results:Both stems showed excellent clinical results. A high offset option was used in 60% of all cases. No postoperative dislocations were observed. The biological fixation was stable in all cases. The hip offset was restored without excessive leg lengthening in most cases.Conclusion:Anatomical consistency could be maintained by using a stem which matched geometry of the proximal part and had offset option. These cementless tapered stems having a high offset option are suitable for Crowe I to III hip dysplasia if two-dimensional X-ray templates fit the shape of the proximal femurs. They were associated with excellent clinical results and biological fixation. The offset option may be useful to adjust leg length and offset in DDH patients.

Background and objectives: The repetitive loading forces generated during football activities may induce alterations in the hip rotation range of motion (ROM) in players. The objective of this study was to evaluate the acute effects of a training and a match on bilateral passive hip rotation ROM in both lower limbs in soccer. Material and methods: Twenty-eight male players were divided into two groups: 14 players (28 limbs) with normal bilateral hip rotation ROM (NH group) and 14 players (28 limbs) with restricted bilateral hip ROM (RH group). Passive bilateral hip rotation ROM was measured, by goniometer, before and after training or a match. Internal-rotation ROM (ROMIR), external-rotation ROM (ROMER), total ROM (ROMTOT) and relative internal rotation (ROMREL) were calculated. Results: The NH group did not show substantial changes in hip ROM after a training nor a match. After a training session, only the RH group exhibited a substantial increase in ROMIR, ROMER and ROMTOT. After a match, only the RH group exhibited a substantial increase in ROMER and ROMTOT and exhibited a substantial decrease in ROMREL. Comparing both groups, there were significant differences within ROM changes for ROMER and ROMTOT after training and for ROMER and ROMREL after a match. Conclusions: Despite the small sample size of the present study, the findings indicate that a single football activity leads to significant changes in hip rotation ROM in players with restricted bilateral hip external-rotation ROM. However, these changes did not reach reference cut-off scores. Sin financiación 2.430 JCR (2020) Q2, 80/169 Medicine, General & Internal 0.530 SJR (2020) Q3, 1256/2448 Medicine (miscellaneous) No data IDR 2019 UEM

Total hip arthroplasty (THA) is often required to decrease the excessive anatomical femoral anteversion (AA) in developmental dysplasia of the hip. Studies have recommended decreasing the AA via the use of a retroverted modular neck. However, hip rotation after THA may strengthen or weaken the effect of changing the AA. Thus, the present study analyzed the effect of a retroverted neck on AA and hip rotation. Patients who underwent THA using a straight neck (ST group) or a 15° retroverted neck (RV group) in a version changeable dual modular system (Mainstay stem, Kyocera, Kyoto, Japan) were retrospectively reviewed. After matching for age, body mass index, and surgical approach, 44 patients were included in each group. The AA and hip rotation (femoral rotational angle: FRA) were measured on CT images acquired preoperatively and 1 month after THA, and were compared between the groups. The mean ± standard deviation preoperative AA of the ST group (26.1 ± 10.7°) was significantly smaller than that of the RV group (44.2 ± 7.8°) (p

The purpose of this study was to compare the rotational profile of adults with higher versus lower foot progression angles (FPA). Tibial torsion, femoral torsion, hip internal and external rotation and FPA data were collected on one hundred two healthy volunteers. Data were stratified into Low, Mid, and High FPA groups to study relationships among the components of the rotational profile and if there were group differences in the magnitude of torsion angles. Direction of torsion was also studied as an attempt to look at the incidence of offsetting between the tibia and femur. Tibial torsion was significantly higher in the High FPA group (p

BACKGROUND Although low back pain (LBP) is known to be multi-factorial, certain studies have suggested that a deficit in hip extension and rotation range of motion (ROM) may be associated with LBP in athletes. OBJETIVE The purpose of this study was to compare hip extension and rotation ROMs in elite tennis players with and without a history of LBP. METHODS Forty-two male and 22 female young elite tennis players completed this study. Participants were divided into two groups: (1) 32 with history of LBP and (2) 32 without history of LBP. Descriptive measures of passive hip extension and rotation ROMs of the dominant and non-dominant limbs were taken. Active hip rotation ROMs were also assessed. Magnitude-based inferences on differences between groups and legs were made by standardizing differences. RESULTS The inter-group statistical analysis reported no significant differences (p> 0.05; trivial effect with a probability higher than 95%; d⩽ 0.4) in any ROM measure analyzed. Further, neither LBP group nor control group reported significant bilateral or side-to-side differences (p> 0.05; trivial effect with a probability higher than 99%; d< 0.3) between legs regarding hip extension and rotation ROM measures. CONCLUSION No relationship between hip extension and rotation ROM and history of LBP was found.

This thesis focuses on measurement of anatomical parameters of lower limb in patients with non-traumatical anterior knee pain. Theoretical part of this work describes basic anatomical, kinesiological and biomechanical knowledge about lower limb. Also there are described basic non-traumatical pathologies of knee and how to assess them. Methodology: in experimental part there were examined and measured these parameters: Q angel, foot pronation and range of hip rotation of 28 sportsmen, of which 7 had unilateral anterior knee pain and 4 had bilateral anterior knee with no previous traumatic experience of the knee. Assessing of angles was made through photographic goniometry using Adobe Illustrator to measure angles on digital pictures. Results: the work did not confirm any of hypothesis, that a statistically significant deviation would be found in patients with anterior knee pain compared to heathy population in at least one of the measured parameters. However further analysis of measured data showed statistically significant correlations between foot pronation and range of internal hip rotation and Q angle and range of external hip rotation both in patients with anterior knee pain compared to healthy population where no such correlation was found. Conclusion: This work suggests existence of connection between...

Internal hip rotation in cerebral palsy (CP) is typically treated with a femoral derotation osteotomy. This has been shown to be largely a successful procedure but recurrence rates up to 41% have been reported. Reported risk factors include younger age, reduced hip joint impulse and ankle plantar-flexion. We report on two patients with bilateral CP demonstrating recurrent unilateral internal hip rotation despite surgical intervention(s). Both demonstrate a number of the reported risk factors for recurrence. In addition, this case report specifically compared gait kinematic patterns pre and post recurrence. On comparing both patient’s hip rotation and ankle dorsi/plantarflexion kinematics they are seen to be almost identical both pre-operatively and post-operatively. Both patients appear to revert to approximately 30o of internal hip rotation which has been shown to maximise hip abductor function. Therefore, this case report suggests that surgical derotation in isolation is unlikely to be successful in this group and we suggest that this hip and ankle pattern may help predict recurrence in unilateral internal hip rotation.

Golf is a common recreational and competitive sport that requires full hip rotation to allow for a smooth and effective swing. Therefore hip impingement and hip osteoarthritis, by limiting rotation, could cause pain in golfers and even encourage them to discontinue the sport. In my opinion, the lead hip in golfers is likely what generally drives the symptoms in the hip, back, or knee. After surgical correction, golfers are able to get back to golf and many experience improved performance.

Anna Swärd Aminoff,1 Cecilia Agnvall,2,3 Carl Todd,1 Páll Jónasson,4 Mikael Sansone,1 Olof Thoreson,1 Leif Swärd,1 Jon Karlsson,1 Adad Baranto1 1Department of Orthopaedics, Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg, and Sahlgrenska University Hospital, Gothenburg, Sweden; 2Sports Medicine Åre, Åre, Sweden; 3Åre Ski Academy, Åre, Sweden; 4Orkuhúsið Orthopedic Clinic, Reykjavik, Iceland Background: Current knowledge of the effect of changes in posture and the way cam morphology of the hip joint may affect hip range of motion (ROM) is limited. Purpose: To determine the effect of changes in pelvic tilt (PT) on hip ROM and with/without the presence of cam. Study design: This was a cross-sectional study. Materials and methods: The hip ROM of 87 subjects (n=61 young elite skiers, n=26 nonathletes) was examined using a goniometer, in three different seated postures (flexed, neutral, and extended). The hips of the subjects were further subgrouped into cam and no-cam morphology, based on the magnetic resonance imaging findings in the hips. Results: There was a significant correlation between the hip ROM and the seated posture in both extended and flexed postures compared with the neutral posture. There was a significant decrease in internal hip rotation when the subjects sat with an extended posture with maximum anterior PT (p

INTRODUCTION: Performing physical activities on a compliant surface alters joint kinematics and increases joints stiffness. However, the effect of compliant surface on joint kinematics after ACL-rupture is yet unknown. AIM: To compare the effects of mechanical perturbation training with a compliant surface to manual perturbation training on joint kinematics after ACL-rupture. METHODS: Sixteen level I/II athletes with ACL-rupture participated in this preliminary study. Eight patients received mechanical perturbation with compliant surface (Mechanical) and 8 patients received manual perturbation training (Manual). Patients completed standard gait analysis before (Pre) and after (Post) training. RESULTS: Significant group-by-time interactions were found for knee flexion angle at initial contact (IC) and peak knee flexion (PKF) (p ≤ 0.004), with manual group significantly increased knee flexion angle at IC and PKF (p ≤ 0.03). Main effects of group were found for hip flexion angle at IC (Manual:34.34±3.51°, Mechanical:27.68±4.08°, p = 0.011), hip rotation angle at PKE (Manual: −3.40±4.78°, Mechanical:5.43±4.78°, p < 0.0001), and knee adduction angle at PKE (Manual: −2.00±2.23°, Mechanical:0.55±2.23°, p = 0.039). Main effects of time were found for hip adduction angle at PKE (Pre:6.98±4.48°, Post:8.41±4.91°, p = 0.04), knee adduction angle at IC (Pre: −2.90±3.50°, Post: −0.62±2.58°, p = 0.03), ankle adduction angle at IC (Pre:2.16±3.54, Post:3.8±3.68, p = 0.008), and ankle flexion angle at PKF (Pre: −4.55±2.77°, Post: −2.39±3.48°, p = 0.01). DISCUSSION: Training on a compliant surface induces different effects on joint kinematics compared to manual perturbation training after ACL-rupture. Manual perturbation improved hip alignment and increased knee flexion angles, while mechanical training decreased knee flexion angles throughout the stance phase. Administering training on a compliant surface after ACL-rupture may help improving dynamic knee stability, however, long-term effects on knee health needs to be determined.

The aim of this study was to establish the torsional and toe-walking profiles of children with autism spectrum disorder (ASD), and to analyze the correlations between torsion, toe-walking, autism severity score, and age. In total, 79 consecutive children with autism were examined to determine their hip rotations, thigh-foot angle, degree of toe-walking, and autism severity. Femoral and tibial torsion values, of the preschool patients, were compared statistically with age-matched controls. The hip rotation profile of the patients was similar to the normal group. Nearly a half of the patients with ASD present excessive external tibial torsion. The difference in the tibial torsion between patients and normal children was statistically significant. A weak correlation was found only between tibial torsion and the autism severity score, but no correlation was found between the other parameters. External tibial torsion is the cardinal and persistent orthopedic manifestation among patients with ASD. Toe-walking is the second most common such manifestation and is an independent orthopedic feature in these patients. External tibial torsion may potentially contribute toward the described gait abnormalities in patients with ASD.

No specific hip joint anatomy has been identified as a risk factor for anterior cruciate ligament (ACL) injury in females. This study was conducted to elucidate the correlation of hip rotation with ACL injury incidence in female handball players, and to clarify the association of hip rotation with knee valgus motion, during ACL injury screening tasks, that is a strong predictor of ACL injury. Of 17 female university handball players, the 8 ACL-injured players displayed greater internal and smaller external rotation of the hip than the 9 uninjured players. Logistic regression analyses demonstrated significant association between hip rotation and ACL injury. Hip internal rotation dominance (internal rotation range is greater than external one) was found in 7 out of the 8 ACL-injured females in contrast to 3 out of the 9 uninjured. Knee valgus was induced in 24 and 22 of the 31 healthy female volunteers by vertical jump and single-leg squat tests, respectively. The knee valgus-positive females showed a smaller range of hip external rotation than the negative ones, which was significantly associated with knee valgus during the screening tests. Hip internal rotation dominance was significantly related to knee valgus induced by each screening test. In contrast to the females, male subjects showed lower rates of knee valgus induction by the screening tests, whereas there was no clear association between hip internal rotation dominance and the knee valgus induction. The present findings may indicate the important role of hip rotation measurement in identification of females at risk for ACL injury.

[Purpose] This study aimed to categorize the internal and external rotation range of motion (ROM) of ipsilateral hip joints into specific patterns based on the differences between them, and clarify the distribution of these patterns. [Subjects and Methods] A total of 222 healthy Japanese medical students (162 males, 60 females) with a mean age of 21.2 ± 4.0 years were enrolled. The ROM of internal and external rotation at the hip were randomly measured with the subjects in the prone position. Thereafter, the difference between internal and external rotations was assessed. Hip ROM patterns were classified into 3 types based on the differences in the rotation ROM on each side. A total of 9 overall patterns were then determined based on the combination of patterns on both sides. [Results] Although all the subjects were healthy, an asymmetrical ROM between internal and external rotation in ipsilateral hip joints could be detected via pattern classification. Moreover, the distribution of each hip ROM pattern was clarified. [Conclusion] Pattern classification based on differences in internal and external rotation ROM could serve as a useful evaluation method for clinical manipulative therapy.

Background Hip rotation range-of-motion (ROM) impairment has been proposed as a contributing mechanical factor in the development of low back pain (LBP) symptoms. There is a hypothesis which suggests that a limited range of hip rotation results in compensatory lumbar spine rotation. Hence, LBP may develop as the result. This article reviews studies assessing hip rotation ROM impairment in the LBP population. Material and methods The MEDLINE and EMBASE databases were searched without time restriction. Two authors independently selected related articles using the same search strategy and key words. Results Among 124 articles 12 met the review inclusion criteria. The results of the studies are assessed in three sections, investigating the relationship between low back pain and 1) hip internal rotation ROM, 2) hip external rotation ROM and 3) hip total rotation ROM. Asymmetrical (right versus left, lead versus non-lead) and limited hip internal rotation ROM were common findings in patients with LBP. Reduced and asymmetrical total hip rotation was also observed in patients with LBP. However, none of the studies explicitly reported limited hip external rotation ROM. Conclusion The precise assessment of hip rotation ROM, especially hip internal rotation ROM, must be included in the examination of patients with LBP symptoms.

According to the literature, the risk of developing iliotibial band syndrome (ITBS) is related to the running technique of each runner. The purpose of this study was to investigate whether differences exist in the running technique of runners with ITBS and healthy runners. The sample was composed of 60 recreational runners (30 healthy runners and 30 with ITBS). A 3D kinematic analysis was performed to measure 3D joint angles of the lower limb. Reaction forces in the stance phase of running were also determined. Runners in the ITBS group exhibited significantly lower contact time, knee valgus, peak knee flexion and hip rotation. Of note, gender-based differences were observed. No differences were found between groups in hip adduction angle, tibial internal rotation and foot kinematics. The runners with current ITBS showed an altered kinematic profile. Male and female runners with ITBS showed different alterations in running kinematics. These results suggest that gender should be considered when investigating the biomechanical etiology of ITBS.

Regarding hamstring stretching methods, many studies have investigated the effect of stretching duration or frequency on muscle stiffness. However, the most effective stretching positions for hamstrings are unclear because it is impossible to quantify muscle elongation directly and noninvasively in vivo. Recently, a new ultrasound technology, ultrasonic shear wave elastography, has permitted noninvasive and reliable measurement of muscle shear elastic modulus, which has a strong linear relationship to the amount of muscle elongation. This study aimed to investigate the effect of hip internal and external rotation on shear elastic modulus of the lateral and medial hamstrings, respectively, during stretching in vivo using ultrasonic shear wave elastography. Twenty-three healthy men (age, 23.0 ± 2.1 years) were recruited for this study. To investigate the effect of hip rotation on the elongation of the medial and lateral hamstrings, shear elastic modulus of the biceps femoris (BF) and semitendinosus (ST) was measured at rest (a supine position with 90° knee flexion, 90° hip flexion, and hip neutral rotation) and in seven stretching positions (with 45° knee flexion and hip internal, external, and neutral rotation) using ultrasonic shear wave elastography. In both BF and ST, the shear elastic modulus in the rest position was significantly lower than that in all stretching positions. However, no significant differences were seen among stretching positions. Our results suggest that adding hip rotation at a stretching position for the hamstrings may not have a significant effect on muscle elongation of the medial and lateral hamstrings.

[Purpose] The aim of this study was to elucidate the difference in hip external and internal rotation ranges of motion (ROM) between the prone and sitting positions. [Subjects] The subjects included 151 students. [Methods] Hip rotational ROM was measured with the subjects in the prone and sitting positions. Two-way repeated measures analysis of variance (ANOVA) was used to analyze ipsilateral hip rotation ROM in the prone and sitting positions in males and females. The total ipsilateral hip rotation ROM was calculated by adding the measured values for external and internal rotations. [Results] Ipsilateral hip rotation ROM revealed significant differences between two positions for both left and right internal and external rotations. Hip rotation ROM was significantly higher in the prone position than in the sitting position. Hip rotation ROM significantly differed between the men and women. Hip external rotation ROM was significantly higher in both positions in men; conversely, hip internal rotation ROM was significantly higher in both positions in women. [Conclusion] Hip rotation ROM significantly differed between the sexes and between the sitting and prone positions. Total ipsilateral hip rotation ROM, total angle of external rotation, and total angle of internal rotation of the left and right hips greatly varied, suggesting that hip joint rotational ROM is widely distributed.

Objective - to study the effect of tunnelization and apparatus hip decompression on the state of proximal femur growing plate. Material and methods. A pattern of changes in proximal femur growing plate of the affected and intact extremities was investigated in 46 children with III degree Perthes disease. The follow-up was 3 years. To unload the affected joint, an external fixator (most often, the Ilizarov apparatus) was placed on pelvic and femoral bones, which was used in a mode of non-articulating arthrodiastasis. The measurements of width of proximal femur growing zone were performed on pelvic bones rentgenograms in anteroposterior projection with internal hip rotation achieved with 1 meter focal length and their subsequent transfer to a digital format. Results. In the study group wire tunneling and apparatus fixation were shown not to result in growing plate locking, providing conditions for recovery of the shape and structure of the femoral head, which was accompanied by a slowdown in its width decrease in the affected extremity and led to the compliance of this parameter between the intact and affected extremities. No correlation was revealed between the degree of structural metaphyseal damage and the state of proximal growing zone.

Background During throwing, the force generated by the lower extremities is transferred through the core, shoulder, elbow, and ultimately, the hand before ball release via the kinetic chain. Therefore, an insufficient hip rotation range of motion (ROM) can arrest the throwing mechanics. Recently, we developed a new scoring system of hip stiffness (Hip Stiffness Score; HSS) for medical assessment of baseball players. In this study, we investigated the correlation between HSS and shoulder conditions in the baseball pitchers. Materials and methods Twenty-seven professional baseball pitchers volunteered for this study. HSS to quantitatively evaluate hip stiffness includes 4 physiologic parameters, including 1 straight leg raising (SLR) test, 2 hip internal rotation (HIR), 3 adduction, and 4 heel buttock distance (HBD). Bilateral glenohumeral internal and external-rotation (IR and ER) ROM were also measured passively, and IR and ER strength of shoulder were assessed bilaterally. In the ultrasound assessments, all participants were scanned by using an Aplio™500 to assess the muscle thickness of supraspinatus (SSP) and infraspinatus (ISP). Results HSS showed a mild positive correlation with total arc of motion (TAM), weak positive correlations with glenohumeral internal rotation deficit (GIRD) and glenohumeral external rotation gain (GERG), and weak negative correlations with IR and ER strength. Then, the participants were divided into 2 groups according to HSS; more than 3 points of HSS was regarded as a high HSS group (n = 12), and less than 2 points as a low HSS group (n = 15). The GERG in the high HSS group was significantly greater than that in the low HSS (p Discussion HSS has some correlations with TAM, GIRD, GERG, IR and ER strength of shoulder. It is assumed that the insufficient hip ROMs could inhibit the kinetic chain in throwing motion. Furthermore, the pitchers with the higher HSS showed greater GERG and lower ER strength. The increase of GERG and decrease of ER strength were reported to lead to shoulder and elbow injuries. Therefore, it is possible that the HSS could be useful for the medical check-up of the pitchers.

Active range of motion trials are frequently used as a baseline for normalizing other data. However, previous research has not focused on methods utilized to achieve maximum active range of motion.Twenty-seven males (age 20-38 years) participated in this study. Active hip extension in upright standing was compared to active lumbar extension with regards to degrees of total hip and spine extension obtained. Similarly, active spine rotation whereby participants attempted to constrain associated pelvis and hip rotation was compared to rotation trials in which the pelvis and hips were free to rotate concurrently. An infra-red motion capture system and associated software were used to capture movement and determine joint angles.Results indicate that average degrees of hip extension did not differ between the two methods (p = 0.138), nor did either method result more frequently in the highest measurement. Spine extension values were significantly greater in the active spine extension manoeuvre compared to the associated back extension that occurred when participants were asked to actively extend their hip (p 0.001). Average degrees of spine rotation were greater in the unconstrained trials: when concurrent hip and pelvis rotation were allowed to take place (p 0.001). Of the 27 participants, 23 obtained maximum rotation during the unconstrained trials.To obtain maximum active hip joint extension, both hip and back extension trials should be collected. Maximum spine rotation is more likely to occur when the pelvis and hips are unconstrained.

The curving motion of the human body is more complex than gait motion for straight walking. In particular, when human can freely curve corners, the gait motion varies among and even within individuals. However, is it not possible to classify natural curving motion using a statistical method? This study investigates the natural curving motion, encompassing various walking paths selected by subjects, as opposed to previous studies that focused on specific stepping strategies or curving motion under precisely controlled conditions. As a result, the natural curving motions are statistically classified into five distinct groups based on certain motion indices. Each group represents a curving strategy and is mainly characterized by the inner inclination of the pelvis, outer rotation of hip joints at the time of heel contact of the inner leg, and inner and/or outer rotation of hip joints at the time of heel contact of the outer leg. Such strategies are speculated as typical motions within the large variation in natural curving motion. Another finding is that, unlike the joint pattern of lower limb joints in the sagittal plane, hip rotation and the abduction/adduction angle drastically change when curving. In particular, the large inner rotation and abduction angles of the hip joint of both legs, which reached approximately 30° and 10°, respectively, become important when considering the curving gait of a physical assistant robot. Our analysis and findings help specify the joint motion required for physical assistant robots., ファイル公開：2019-02-01

Background Adolescent tennis players require sufficient hip and shoulder flexibility to achieve the kinetic chain of a tennis stroke or serve. Hence, the objective of this study is to measure the glenohumeral joint internal and external rotation (IR and ER, respectively) and hip ER range of motion (ROM) and to compare these parameters between experienced and beginner-level adolescent tennis players. Methods Twenty-three adolescent tennis players were divided into experienced (N.=12) and beginner groups (N.=11) on the basis of the adolescent national ranking of the Taiwan Tennis Association. For all participants, the shoulder IR and ER at 90° of abduction were measured, and hip ER which used Partick's Test was also evaluated on the dominant and nondominant sides. The total rotation ROM of the shoulder and the difference in shoulder ER, IR, and total rotation and hip ER between the dominant and nondominant sides were also calculated after measurements. An independent-samples t-test was applied to test the homogeneity of the participants' demographic data and the difference in shoulder IR, ER, and total rotation and hip ER values between the dominant and nondominant sides. Subsequently, a repeated-measured two-way analysis of variance (2 × 2) was used to compare the dominant and nondominant shoulder and hip ROM of the participants between the experienced and beginner groups. Results The experienced group exhibited a significantly less total rotation ROM than the beginner group. In addition, both groups showed less dominant shoulder IR ROM and more dominant shoulder ER ROM compared with the nondominant side. Compared with the experienced group, the beginner group showed an obvious difference in total shoulder rotation between dominant and nondominant sides. More tightness for the hip ER was observed in the experienced group than in the beginner group, but no difference was observed between the dominant and nondominant sides in both groups. Conclusions Beginner adolescent tennis players differ more in the degree of total shoulder ROM between the dominant and nondominant sides than experienced players. Beginner and experienced adolescent tennis players also have more shoulder ER and less IR on the dominant side. The results suggest that beginner-level adolescent tennis players should undergo a stretching and strengthening program to reduce the potential risk of injury and possibly enhance performance.

Background Femoroacetabular impingement (FAI) is becoming a prevalent overuse injury diagnosis among hockey players. In the adult ice hockey stride, the “at-risk” hip position, defined by internal rotation during flexion and external rotation during abduction, reportedly increases hip vulnerability to labral injury as a result of FAI. Hypothesis Peewee youth ice hockey players display the kinematics for both described at-risk hip positions (internal rotation during flexion and external rotation during abduction) in the ice hockey sprint start. Study Design Descriptive laboratory study. Methods Twelve healthy male Peewee ice hockey players (mean age, 10.8 ± 0.6 years) participated in this study. Thirty-five anatomic landmarks were used to analyze the 3-dimensional kinematic and kinetic variables of the hip associated with the ice hockey sprint start. Ten high-speed (120-Hz) infrared cameras recorded the trials, which were subsequently analyzed with Motion Monitor software. The sprint start was recorded over 4 defined periods of motion: start, push, swing, and even. Results In the “push” period, 11.5° of external rotation was observed concurrently with 13.2° of abduction in the push leg, and 6.8° of internal rotation occurred with 33.8° of flexion in the lead leg. During the recovery phase of the “swing” period, maximum internal rotation was 5.6° with concurrent hip flexion of 44.2° in the push leg, while lead leg internal rotation reached a maximum of 10.8° with hip flexion of 35.1° during the “even” period. Conclusion During the sprint start, youth ice hockey players externally rotate in abduction during the push-off phase and internally rotate through increasing hip flexion during the recovery phase, displaying the at-risk hip positions of the ice hockey skating stride. Clinical Relevance During the sprint start, youth ice hockey players position their hips in a manner that can cause impingement of the femoral neck against the acetabulum and potentially lead to labral tears and/or articular cartilage damage. This knowledge could be applied to assist in the prevention of overuse injuries of the hip as youth hockey players mature and increase in skill level.

The purpose of the present study was to examine the relationship between hip muscle strength (abduction and external rotation) and frontal-plane knee control during drop jumping in recreational female athletes. Thirty-three healthy young recreational female athletes were included. Maximal isometric hip abduction and external rotation torque were measured using hand-held dynamometry, and frontal-plane knee control during drop jumping was assessed using three-dimensional motion analysis. Frontal-plane knee control during drop jumping was expressed as the absolute (cm) and relative (cm/cm body height) change in distance between lateral knee markers from foot-ground contact to the time of minimal marker distance during the contact phase of the jump. Greater maximal external hip-rotation torque correlated significantly with greater absolute (r=0.48, P=0.005) and relative (r=0.43, P=0.012) change in knee marker distance during drop jumping. Maximal hip-abduction torque did not correlate with the absolute (r=0.18, P=0.31) or relative (r=0.19, P=0.29) change in knee marker distance during drop jumping. Contrary to our expectations, greater maximal external hip-rotation torque was related to greater change in knee marker distance during drop jumping (reduced frontal-plane knee control) in recreational female athletes.

Total hip arthroplasty (THA) in the presence of developmental dysplasia of the hip (DDH) can be technically challenging. Restoring the anatomic center of hip rotation may require femoral osteotomy. Techniques using cementless components are widely reported but less is known about using cemented components that may be more appropriate with osteopenic bone.We therefore determined the rate of union, complications, and early functional score in a series of patients with DDH who underwent cemented THA and simultaneous subtrochanteric osteotomy.We retrospectively reviewed 28 patients (35 hips) who underwent a cemented THA for DDH at a mean age of 47.3 years. Two patients (two hips) died within 12 months of surgery of unrelated conditions. The clinical notes and radiographs were reviewed with a minimum followup of 2 years (mean, 5.6 years; range, 2-14 years). Complications were noted. SF-12 and Oxford hip scores (OHS) were recorded for 18 patients preoperatively and after 6 and 12 months.Union occurred in 32 of 33 femora (97%); one patient had an infected nonunion. The overall revision rate was 20% (9% femoral revision rate). There were three dislocations, two of which had further surgery. Two patients had a transient neuropraxia. The mean SF-12 physical component score increased from 32 to 52 and mean SF-12 mental component score increased from 48 to 51. The mean OHS decreased from 40 to 27.Combined subtrochanteric osteotomy and cemented THA is technically demanding with a higher complication rate than routine THA. The rate of union, complications, implant survival, and early OHS were comparable to those for similar techniques using cementless components.

Background Joint motion studies suggest that adults have symmetrical hip rotation range of motion. Asymmetries in hip rotation are often related to lower extremity musculoskeletal conditions. The purpose of this study was to determine if muscle strength differences occur in subjects with symmetrical vs. asymmetrical hip rotation. We hypothesize that those with asymmetrical hip rotation will have less strength in the standard 0° test position when compared to a position where the joint is in its center or mid-position. Methods Sixty-four subjects participated. Muscle strength was measured in the standard 0° and mid-range hip positions. Subjects were divided into three groups depending on hip rotation, symmetrical, internal rotation greater than external rotation and external rotation greater than internal rotation. Data were analyzed using a 3 (Classification Group: Symmetrical vs. greater external rotation vs. greater internal rotation) × 2 (Muscle: External Rotator vs. Internal Rotator) × 2 (Position: Standard 0° vs. Center or Off-mid) ANOVA with the last two factors treated as repeated measures. Findings Measures of left and right side yielded significant effects for Muscle, Classification Group × Muscle, Classification Group × Position, Muscle Group × Position, and Classification Group × Muscle × Position. Interpretation The results suggest that difference in muscle strength of the hip rotators is dependent upon the position that the hip rotator muscle is tested and the type of hip rotation symmetry or asymmetry present. Before muscle testing or strengthening the hip rotator muscles the presence of joint rotation asymmetries and the effect of joint positioning must be considered.

Objective To investigate whether amateur golfers with self-reported low back pain have reduced hip rotation compared to asymptomatic controls. Design Observational case-control study. Setting Data collection took place at 2 amateur golf clubs in southern England. Participants On initial contact, all participants completed a screening questionnaire used to allocate participants into LBP ( n =28) and control groups ( n =36). LBP group were found to be heavier than controls ( t =2.242, 95% CI 0.763–13.332) but were matched for age, height, handedness, handicap, rounds played per week and years of play. Main outcome measures Primary outcome measures were lead and non-lead hip medial and lateral rotation in 0° of flexion as measured by inclinometer. Secondary measures included inter and intra-rater reliability. Results The LBP group had significantly reduced lead hip passive (LBP 21.14±10.17°; controls 31.06±8.06°, t =−4.228, 95% CI −14.621–−5.205) and lead hip active medial rotation (LBP 21.46±10.01; controls 28.06±7.49°, t =−2.908, 95% CI −11.147–−2.036) compared to controls. No between group differences were found in non-lead hips or any passive or active lateral rotation measures. Conclusion Although there is lack of causality between LBP and hip rotation, the deficit in lead leg medial hip rotation in amateur golfers who suffer LBP may be relevant for screening or treatment selection.

BACKGROUND: Gluteus maximus strengthening exercises are employed in clinical practice as options for the treatment of low back and sacroiliac disorders. However, no studies were found that investigated which were the best exercises to activate this muscle and justify its employment in physical therapy practice. OBJECTIVE: To quantify the electromyographic (EMG) activity of the gluteus maximus and semitendinosus muscles during four modalities of therapeutic exercises. METHODS: Thirty-one participants (16 men, 15 women) were selected. The EMG activities of the gluteus maximus and semitendinosus was recorded and quantified while the participants performed four modalities of therapeutic exercises, involving active prone hip extension in four positions: knee extension (KE), knee flexion (KF), lateral hip rotation and knee extension (LHRKE), and lateral hip rotation and knee flexion (LHR-KF). RESULTS: Repeated-measures ANOVAs showed that the addition of KF or LHR increased gluteus maximus activity, whereas, KE decreased the activation of this muscle. In contrast, the exercises performed with KE increased semitendinosus activity. CONCLUSIONS: Exercises performed with KF or LHR, or a combination of the two, may be effective choices for gluteus maximus strengthening, however both KF and LHR decreased semitendinosus activity. The exercises performed with KE appeared to be an acceptable choice for semitendinosus activation.

[Purpose] Kendo practitioners often suffer from left low back pain. The present study was undertaken to analyze the features of range of motion (ROM) of the hip joint of kendo practitioners and their relation to prevention of lower back pain. [Subjects and Methods] The study involved 37 male university kendo practitioners: 26 kendo practitioners having a history of lower back pain, 11 kendo practitioners having no history of lower back pain. In accordance with the method of ROM measurement set forth by the Japanese Orthopaedic Association, the same examiner measured hip joint ROM during passive flexion/extension and internal/external rotation. [Results] In the low back pain group, no laterality was noted in the ROM of the external rotation. However, ROM of the internal rotation was significantly smaller on the left side than on the right side. The range of rotation was significantly smaller on the left side than on the right side. [Conclusion] The ROM of hip rotation on the left side was significantly diminished (less than 90 degrees) only in the low back pain group, and the laterality in ROM of left hip rotation was significantly greater in the low back pain group than in the non-low back pain group (p

Objective To examine whether passive hip rotation motion was different between people with and without low back pain (LBP) who regularly participate in sports that require repeated rotation of the trunk and hips. We hypothesized that people with LBP would have less total hip rotation motion and more asymmetry of motion between sides than people without LBP. Design Two group, case control. Setting University-based musculoskeletal analysis laboratory. Participants Forty-eight subjects (35 males, 13 females; mean age: 26.56±7.44 years) who reported regular participation in a rotation-related sport participated. Two groups were compared; people with LBP ( N =24) and people without LBP ( N =24; NoLBP). Main outcome measures: Data were collected on participant-related, LBP-related, sport-related, and activity-related variables. Measures of passive hip rotation range of motion were obtained. The differences between the LBP and NoLBP groups were examined. Results People with and without a history of LBP were the same with regard to all participant-related, sport-related and activity-related variables. The LBP group had significantly less total rotation ( P =.035) and more asymmetry of total rotation, right hip versus left hip ( P= .022) than the NoLBP group. Left total hip rotation was more limited than right total hip rotation in the LBP group ( P =.004). There were no significant differences in left and right total hip rotation for the NoLBP group ( P =.323). Conclusions Among people who participate in rotation-related sports, those with LBP had less overall passive hip rotation motion and more asymmetry of rotation between sides than people without LBP. These findings suggest that the specific directional demands imposed on the hip and trunk during regularly performed activities may be an important consideration in deciding which impairments may be most relevant to test and to consider in prevention and intervention strategies.

Turnout, or external rotation (ER) of the lower extremities, is essential in ballet. The purpose of this study was to utilise physical examination and a biomechanical method for obtaining functional kinematic data using hip and knee joint centres to identify the relative turnout contributions from hip rotation, femoral anteversion, knee rotation, tibial torsion, and other sources. Ten female dancers received a lower extremity alignment assessment, including passive hip rotation, femoral anteversion, tibial torsion, weightbearing foot alignment, and Beighton hypermobility score. Next, turnout was assessed using plantar pressure plots and three-dimensional motion analysis; participants performed turnout to ballet first position on both a plantar pressure mat and friction-reducing discs. A retro-reflective functional marker motion capture system mapped the lower extremities and hip and knee joint centres. Mean total turnout was 129±15.7° via plantar pressure plots and 135±17.8° via kinematics. Bilateral hip ER during turnout was 49±10.2° (36% of total turnout). Bilateral knee ER during turnout was 41±5.9° (32% of total turnout). Hip ER contribution to total turnout measured kinematically was less than expected compared to other studies, where hip ER was determined without functional kinematic data. Knee ER contributed substantially more turnout than expected or previously reported. This analysis method allows precise assessment of turnout contributors.

Background The aim of the present study was to assess midterm results after acetabular impaction bone grafting (IBG) in primary total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH) with large acetabular segmental defect. Methods Primary THA with IBG for DDH with large acetabular segmental defect was performed in 40 hips of 38 patients. The average age was 61.6 years (range: 33-82 years), and the average follow-up period was 7.5 years (range: 3-10.3 years). The Merle d'Aubigne and Postel hip score and complications were assessed. For radiological assessment, postoperative location of the hip rotation center, the socket inclination angle, and the socket center-edge angle were assessed. Kaplan-Meier survival analysis was performed with the end points of any type of reoperation and aseptic acetabular loosening. Results The mean Merle d'Aubigne and Postel hip score improved from 10.4 points to 16.2 points at the final follow-up. Reoperation was performed in 1 case for acute infection without loosening. In 39 out of 40 hips (97.5%), the center of hip rotation was located beneath the "high hip center." The average socket inclination angle was 39.3° (range: 30°-54°), and the average socket center-edge angle was −11.8° (range: −23° to 9°). Survival rate of acetabular component at 8 years with the end point of any reoperation and of aseptic loosening was 96.6% (95% confidence interval: 89.9%-100%) and 100%, respectively. Conclusion Acetabular IBG represents one of the useful options for restoring a normal hip center and acetabular bone stock in primary THA for DDH with large acetabular defect.

Contradictions exist between studies of the 3D kinematics of the knee. We hypothesize that they are in part due to differences in the gesture performed by the subjects during kinematic assessment. The purpose of this study is to evaluate the impact of gesture variations on knee kinematics. Seventeen healthy male subjects performed 20-s series of knee-bends in a knee-bend standardizing structure. All series differed regarding either foot rotation, knee excursion, or hip rotation. 3D knee kinematics were recorded using optical position sensors mounted on a skin-motion-reducing harness. Kinematic comparisons were made between a gesture of reference (the standard gesture) and every other gesture. Analyses were performed on average differences. Differences of up to 15 degrees of tibial rotation were found for gestures involving different foot rotation. Gestures involving different knee excursion brought on differences of more than 4 degrees of tibial rotation while hip rotation induced more than 5 degrees of tibial rotation. It is hereby demonstrated that gesture differences can have a dramatic impact on measured knee kinematics. Hence gesture performance needs to be carefully monitored during 3D kinematic assessment of the weight-bearing human knee.