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Poor knee biomechanics in a volleyball spike jump generally result in a higher knee injury risk, which can be altered by an internal focus of attention (FOA). The constrained action hypothesis (CAH) purports that the FOA inhibits sports performance whereas no ecologically valid evidence has been found in previous studies. The purpose of this research is to explore the effect of video feedback on knee biomechanics in a volleyball spike jump including landing and take-off phases. The video feedback was performed in a natural way. Fourteen volleyball male players were recruited in this study. A paired t-test was used to detect the effect of the feedback, meanwhile, statistical parameter mapping (SPM) statistics were used for the continuum differences during movement. After biofeedback, the initial contact flexion angle of the knee (t = 2.179, p = 0.049), the maximal flexion angle of the knee (t = 3.242, p = 0.006) and the maximal internal rotation angular velocity of the knee (t = 5.209, p = 0.003) increased significantly, the maximal extension moment of the knee (t = 3.962, p &lt, 0.001) and the maximal flexion moment of the knee (t = −3.711, p = 0.002) significantly decreased, the maximal abduction moment significantly decreased (t = 3.069, p = 0.037) but the maximal internal rotation moment significantly increased (t = 2.813, p = 0.018), the first peak of the vertical ground reaction force (vGRF) (t = 7.618, p &lt, 0.001) and the average loading rate to the first peak (t = 4.205, p = 0.004) significantly decreased, the other peaks of the vGRF were not found to have differences, a larger knee flexion was found during the phase from 31.17 to 73.19% (t = 2.611, p = 0.012), a larger adduction angular velocity was found during the phase from 49.07 to 62.46% (t = 3.148, p = 0.004), a smaller external rotational angular velocity was found during the phase from 45.85 to 49.96% (t = 5.011 p = 0.017), there was an increased flexion moment of the knee during the phase from 19.72 to 21.38% (t = 0.029, p = 0.029) and an external moment of the knee during the phase from 85.55 to 95.06% (t = 4.214, p &lt, 0.001), the vGRF significantly decreased during the phase from 3.13 to 5.94% (t = 4.096, p = 0.014) and 19.83–21.97% (t = 4.096, p = 0.024) but significantly increased in the phase of 91.43–100% (t = 4.096, p &lt, 0.001). The impulse of the vGRF and knee power were not found to be different compared with before biofeedback. Therefore, our study suggests video feedback in a natural practice has the potential to improve knee movement whilst not altering the performance in a volleyball spike jump. This indicates that the CAH theory is possibly not suitable in a real competition. Due to the complexity of human movements and the limitations of this study, muscle activities must be considered in the future.

OBJECTIVE: The purpose of this study was to investigate the influence of thoracic spinal manipulation (SM) on shoulder pain and ranges of motion in individuals with shoulder pain. METHODS: The sample was composed of 60 individuals, randomly allocated into the manipulation group (n = 30), who received the SM, and the placebo group (n = 30) who received a placebo manipulation. Pain evaluation was performed using the visual analog scale, and evaluation of shoulder flexion and abduction ranges of motion was assessed using a goniometer pre- and post-intervention. The intervention was performed by either upper thoracic SM or a placebo manipulation. RESULTS: The manipulation group demonstrated increased flexion and abduction of the painful shoulder (P < .01) and increased abduction of the nonpainful shoulder (P = .03), but only the abduction of the painful shoulder reached the minimal detectable change. The placebo group showed a post-intervention increase in the flexion (P = .03) and abduction (P < .01) movement of the painful shoulder. Both groups presented a statistically significant reduction in post-intervention pain (P < .01), but not clinically significant. CONCLUSION: Although the SM demonstrated a statistically significant difference for shoulder pain, this was not over the clinically meaningful change. Only the abduction of the painful shoulder reached the minimal detectable change.

AimsTo compare patients undergoing total knee arthroplasty (TKA) with ≤ 80° range of movement (ROM) operated with a 2 mm increase in the flexion gap with matched non-stiff patients with at least 100° of preoperative ROM and balanced flexion and extension gaps.MethodsIn a retrospective cohort study, 98 TKAs (91 patients) with a preoperative ROM of ≤ 80° were examined. Mean follow-up time was 53 months (24 to 112). All TKAs in stiff knees were performed with a 2 mm increased flexion gap. Data were compared to a matched control group of 98 TKAs (86 patients) with a mean follow-up of 43 months (24 to 89). Knees in the control group had a preoperative ROM of at least 100° and balanced flexion and extension gaps. In all stiff and non-stiff knees posterior stabilized (PS) TKAs with patellar resurfacing in combination with adequate soft tissue balancing were used.ResultsOverall mean ROM in stiff knees increased preoperatively from 67° (0° to 80°) to 114° postoperatively (65° to 135°) (p < 0.001). Mean knee flexion improved from 82° (0° to 110°) to 115° (65° to 135°) and mean flexion contracture decreased from 14° (0° to 50°) to 1° (0° to 10°) (p < 0.001). The mean Knee Society Score (KSS) improved from 34 (0 to 71) to 88 (38 to 100) (p < 0.001) and the KSS Functional Score from 43 (0 to 70) to 86 (0 to 100). Seven knees (7%) required manipulations under anaesthesia (MUA) and none of the knees had flexion instability. The mean overall ROM in the control group improved from 117° (100° to 140°) to 123° (100° to 130°) (p < 0.001). Mean knee flexion improved from 119° (100° to 140°) to 123° (100° to 130°) (p < 0.001) and mean flexion contracture decreased from 2° (0° to 15°) to 0° (0° to 5°) (p < 0.001). None of the knees in the control group had flexion instability or required MUA. The mean KSS Knee Score improved from 48 (0 to 80) to 94 (79 to 100) (p < 0.001) and the KSS Functional Score from 52 (5 to 100) to 95 (60 to 100) (p < 0.001). Mean improvement in ROM (p < 0.001) and KSS Knee Score (p = 0.017) were greater in knees with preoperative stiffness compared with the control group, but the KSS Functional Score improvement was comparable (p = 0.885).ConclusionTKA with a 2 mm increased flexion gap provided a significant improvement of ROM in knees with preoperative stiffness. While the improvement in ROM was greater, the absolute postoperative ROM was less than in matched non-stiff knees. PS TKA with patellar resurfacing and a 2 mm increased flexion gap, in combination with adequate soft tissue balancing, provides excellent ROM and knee function when stiffness of the knee had been present preoperatively. Cite this article: Bone Joint J 2020;102-B(4):426–433.

Purpose The purpose of this study was to determine the results of mobile bearing unicompartmental knee arthroplasty (UKA) with an intentionally increased flexion angle of the femoral component in patients requiring high flexion. Materials and methods We investigated 45 knees treated by UKA. Clinically, we measured the range of motion (ROM) and the American Knee Society (AKS) score preoperatively and at final follow-up and investigated complications. Radiologically, we measured the flexion angle of the femoral component, the posterior slope angle of the tibial component, the femorotibial angle and mechanical axis of the limb postoperatively. Results The ROM was increased from 123° preoperatively to 139° at the final follow-up. The AKS knee and function scores increased from 59 and 68, respectively, preoperatively to 94 and 96, respectively, at the final follow-up. The flexion angle of the femoral component was 9.1°, and the posterior slope angle of the tibial component was 8.6°. There was one case of bearing dislocation in the largest femoral flexion angle case. Conclusions The results might reflect the positive effect of an increased flexion angle of the femoral component up to 10° on ROM in mobile bearing UKA, which would contribute to better quality of life after UKA especially in populations requiring deep knee flexion.

Background:The use of tranexamic acid (TXA) in total knee arthroplasty (TKA) has shown good results. Bleeding may cause local complications consequently greater pain and reduced function postoperatively. No study has related the use of TXA to these facts.Objective:The aim was to evaluate the effects of TXA haemoglobin, Western Ontario and McMaster Universities Index (WOMAC), pain intensity and flexion gain after TKA.Methods:43 patients were randomized and then underwent TKA. TXA was applied to 22 of these patients before closure of the joint capsule. Haemoglobin measurements (mg/dL) were taken preoperatively and 24 and 48 hours after surgery. The WOMAC questionnaire and pain visual analogue scale (VAS) were applied, and flexion gain was measured up to the second postoperative month. Statistical analysis compared the results to determine whether there were differences between the groups for each of the evaluated times.Results:There were differences in favour of the drug 48 hours postoperatively for the haemoglobin variable (p = 0.01), in pain evaluation, 24 and 48 hours, postoperatively (p < 0.01) and in flexion gain, 24 hours after surgery (p = 0.03). There were no significant differences between the groups in the haemoglobin evaluation 24 hours postoperatively, in pain assessment 7 days, 21 days and 2 months, postoperatively, in flexion gain 48 hours, 7 days, 21 days and 2 months, postoperatively and in WOMAC after 2 months.Conclusion:In addition to reducing bleeding, topical TXA improved pain and increased flexion gain in the first hours after TKA.Trial Registration:RBR-9b4qgq

Previous open-label studies showed that chronic post-stroke pain could be abated by treatment with perispinal etanercept, although these benefits were questioned. A randomized double-blind placebo controlled clinical trial was conducted to test perispinal etanercept for chronic post-stroke pain. Participants received two treatments, either perispinal etanercept (active) or saline (control). Primary outcomes were the differences in daily pain levels between groups analyzed by SPSS. On the 0–100 points visual analog scale, perispinal etanercept reduced mean levels for worst and average daily pain from baseline after two treatments by 19.5 – 24 points (p < 0.05), and pain alleviation was maintained in the etanercept group, with no significant change in the control group. Thirty percent of etanercept participants had near complete pain abatement after first treatment. Goniometry of the paretic arm showed improved mean shoulder rotation by 55 degrees in active forward flexion for the etanercept group (p = 0.003) only. Perispinal etanercept can provide significant and ongoing benefits for the chronic post-stroke management of pain and greater shoulder flexion by the paretic arm. Effects are rapid and highly significant, supporting direct action on brain function. ACTRN12615001377527 and Universal Trial Number U1111-1174-3242.

Background In general, the flexion gap is larger than the extension gap with posterior cruciate ligament-sacrificing total knee arthroplasty. Several methods compensate for an excessive flexion gap, but their effects are unknown. The purpose of this study was to compare three methods to compensate for an increased flexion gap. Methods In this study, squatting in knees with excessive (4 mm) and moderate (2 mm) flexion gaps was simulated in a computer model. Differences in knee kinematics and kinetics with joint line elevation, setting the femoral component in flexion, and using a larger femoral component as compensatory methods were investigated. Findings The rotational kinematics during flexion with setting the femoral component in flexion were opposite to those in the other models. Using a larger femoral component resulted in the most physiological motion. The peak anterior translation was 10 mm in the joint line elevation model compared with approximately 6 mm in the other models. In the joint line elevation model, patellofemoral contact stress was excessively increased at 90° of knee flexion. In contrast, tibiofemoral contact stress was higher during knee extension with setting the femoral component in flexion due to anterior impingement. There were few differences in the effect of the three compensatory methods with a moderate flexion gap. Interpretation A larger femoral component should be used to compensate for an excessive flexion gap because it has less negative impact on posterior cruciate ligament-sacrificing total knee arthroplasty, whereas any compensation method might be acceptable for a moderate flexion gap.

Background: A thumb interphalangeal (IP) joint arthrodesis is typically performed in 0° to 30° of flexion; most daily activities involve increased flexion at the IP joint to facilitate pinch and grip. This study evaluates the preferred thumb IP joint position with certain tasks of daily living to determine a more satisfactory angle. Methods: Twenty-eight healthy volunteers were splinted at various degrees (0°, 15°, 30°, 45°, bilaterally) with thumb orthotics, leaving the tip free, to mimic various angles of IP fusion. Participants underwent power tasks (pouring from a gallon jug, opening/closing a tight jar, lifting a heavy glass, and opening a door), timed precision tasks (writing, buttoning/unbuttoning a shirt, translating coins, zipping/unzipping a jacket, and opening/closing Velcro), as well as pinch and grip strength testing. All tasks were performed both at baseline (without any splinting) and with the thumb splinted in each angle. Participants used a 10-point Visual Analogue Scale (VAS) to rate the ease of each task as well as their overall satisfaction at baseline and at each of the various angles for their dominant and nondominant hand. Wilcoxon signed rank tests were conducted for outcomes, with P < .05 denoting statistical significance. Results: Power tasks were best accomplished at 0° for the nondominant hand and 0° to 30° for the dominant hand. Precision tasks were preferred at 15° for both dominant and nondominant hand. Grip strength was best at 15° and 0° for the nondominant and dominant hand, respectively. Pinch was equivocal between 0° and 30° for the nondominant hand and from 15° to 30° for the dominant hand. VAS ratings were most similar to baseline at a fusion angle of 15° followed by 30° for the dominant thumb and 30° followed by 15° for the nondominant thumb. Conclusions: A thumb IP fusion angle of 15° to 30° is a functional and preferred angle of thumb IP joint positioning for various activities of daily living.

OpenSim musculoskeletal models of the head and neck can provide information about muscle activity and the response of the head and neck to a variety of situations. Previous models report weak flexion strength, which is partially due to lacking moment generating capacity in the upper cervical spine. Previous models have also lacked realistic hyoid muscles, which have the capability to improve flexion strength and control in the upper cervical spine. Suprahyoid and infrahyoid muscles were incorporated in an OpenSim musculoskeletal model of the head and neck. This model was based on previous OpenSim models, and now includes hyoid muscles and passive elements. The moment generating capacity of the model was tested by simulating physical experiments in the OpenSim environment. The flexor and extensor muscle strengths were scaled to match static experimental results. Models with and without hyoid muscles were used to simulate experimentally captured motions, and the need for reserve actuators was evaluated. The addition of hyoid muscles greatly increased flexion strength, and the model is the first of its kind to have realistic strength values in all directions. Less reserve actuator moment was required to simulate real motions with the addition of hyoid muscles. Several additional ways of improving flexion strength were investigated. Hyoid muscles add control and strength to OpenSim musculoskeletal models of the head and neck and improve simulations of head and neck movements.

AB Purpose: Asymmetric step length is a problem common to many orthopedic and neurologic populations. Herein, we compare step length aftereffects during overground gait after two rehabilitation intervention strategies to combat step length asymmetry: split-belt treadmill (SBT) walking and unilateral stepping. Methods: Eighteen healthy young adults (22 +/- 3 yr) first performed 10 overground gait trials. Participants then walked for 10 min under three different treadmill conditions in a randomized order: SBT walking, slow unilateral stepping, and fast unilateral stepping. Immediately after each treadmill condition, participants performed ten overground gait trials. Mean step length asymmetry was calculated across the first five strides of the overground gait trials to assess the storage of aftereffects after each treadmill condition. We also explored the lower extremity kinematics during each treadmill condition to investigate movement patterns that lead to greatest aftereffects. Results: Significantly higher step length asymmetry was observed in overground gait trials after SBT walking compared to those after slow and fast unilateral stepping, indicating greater aftereffect/carryover of the SBT walking pattern to overground gait. During fast unilateral stepping, increased flexion in the hip, knee, and ankle of the stationary limb was significantly associated with increased step length aftereffects. Conclusions: The aftereffects observed after acute SBT walking were significantly greater than those after unilateral stepping. Both exercises induce aftereffects of similar kinematic patterns, although likely through different mechanisms. In sum, SBT walking induces the greatest aftereffects, although unilateral stepping also induces a change in gait behavior. During unilateral stepping, the largest aftereffects occur when the walker does not simply fully extend the stationary limb and allow the treadmill to passively move the stepping limb during stance.

Because of demographic changes, ever greater demands are made of knee replacement systems by patients and surgeons. To meet these demands, knee joint systems with increased flexion are currently being marketed. The main hypothesis of the present study was to evaluate the functional outcome of a high flexion TKA in amid-term follow up. 75 consecutive patients (29 men and 46 women) who had primary arthritis of the knee with similar deformity and range of motion undergo TKA using a NexGen Cr Flex mobile. Knee Society knee and functional scores and range of motion were assessed. The follow-up duration was 5 years. There was a highly significant improvement in comparison to the preoperative status (p

Objective—To assess forelimbs and hind limb joint kinematics in dogs during walking on an inclined slope (uphill), on a declined slope (downhill), or over low obstacles (cavaletti) on a horizontal surface and compare findings with data acquired during unimpeded walking on a horizontal surface. Animals—8 nonlame dogs (mean ± SD age, 3.4 ± 2.0 years; weight, 23.6 ± 4.6 kg). Procedures—By use of 10 high-speed cameras and 10 reflecting markers located on the left forelimbs and hind limbs, joint kinematics were recorded for each dog during uphill walking, downhill walking, and walking over low obstacles or unimpeded on a horizontal surface. Each exercise was recorded 6 times (10 s/cycle); joint angulations, angle velocities and accelerations, and range of motion for shoulder, elbow, carpal, hip, stifle, and tarsal joints were calculated for comparison. Results—Compared with unimpeded walking, obstacle exercise significantly increased flexion of the elbow, carpal, stifle, and tarsal joints and extension in the carpal and stifle joints. Only uphill walking caused increased hip joint flexion and decreased stifle joint flexion; downhill walking caused less flexion of the hip joint. During obstacle exercise, forward angle velocities in the elbow and stifle joints and retrograde velocity in the tarsal joint changed significantly, compared with unimpeded walking. Joint angle acceleration of the elbow joint changed significantly during all 3 evaluated exercises. Conclusions and Clinical Relevance—These evidence-based data indicated that each evaluated exercise, except for downhill walking, has a specific therapeutic value in physical therapy for dogs.

STUDY DESIGN Biomechanical study using human cadaver spines. OBJECTIVE To characterize kinematics of cervical spines implanted with total disc replacement (TDR) at 2-levels referencing the implanted and adjacent levels. SUMMARY OF BACKGROUND DATA Cervical TDR is an appealing alternative to fusion particularly when treating multilevel disease, where the advantages of maintaining motion and reducing adjacent level stresses with TDR are compelling. To our knowledge there are no biomechanical studies evaluating multilevel cervical TDR. METHODS Six human cadaveric cervical spine specimens (C3-C7, age: 57 +/- 12 years) were tested (i) intact, (ii) after TDR (Discover, DePuy, Raynham, MA) at C5-C6, and (iii) after additional TDR at C6-C7. Specimens were subjected to flexion/extension, lateral bending and axial rotation (+/-1.5 Nm). Segmental range of motion (ROM) was measured using optoelectronic instrumentation and fluoroscopy. RESULTS Insertion of TDR at C5-C6 increased flexion/extension ROM of the implanted segment compared with intact (8.6 +/- 1.0 vs. 12.3 +/- 3.3 degrees , P 0.025) and axial rotation (5.5 +/- 1.9 vs. 6.0 +/- 2.9, P > 0.025). The TDR at C5-C6 did not affect ROM at the adjacent levels. Implantation of a second TDR at C6-C7 maintained the ROM at that segment to intact values in flexion/extension (9.6 +/- 4.3 vs. 11.2 +/- 5.5, P > 0.025), lateral bending (6.1 +/- 4.0 vs. 4.1 +/- 2.1, P > 0.025), and axial rotation (6.7 +/- 3.6 vs. 5.5 +/- 3.7, P > 0.025). The second TDR at C6-C7 did not affect the ROM of the prosthesis implanted at C5-C6. Two-level TDR at C5-C6-C7 did not affect the ROM at C4-C5 in flexion/extension or axial rotation, however, in lateral bending a small increase occurred (8.9 +/- 3.6 vs. 10.1 +/- 4.5, P < 0.025). CONCLUSION Cervical TDR at 2 levels can provide near-normal mobility at both levels without destabilizing the implanted segments or affecting adjacent segment motions. These observations lend support to the notion that single or multilevel cervical TDR may be advantageous when compared to fusion.

This prospective, randomized study reports early results for range of motion (ROM) after primary total knee arthroplasty. Group A received standard posterior-stabilized (PS) implants. Group B had PS implants designed for increased flexion. Average preoperative ROM was 2 degrees to 121 degrees for group A and 1.8 degrees to 122 degrees for group B. At 12-month follow-up, average ROM for group A was 0.6 degrees to 120 degrees as compared with 0.6 degrees to 133 degrees for group B (P.05). Significantly more patients in group B flexed more than 135 degrees (P.05). Furthermore, 12 patients (48%) in group A failed to return to preoperative ROM versus 2 patients (8%) in group B (P.05). Although long-term follow-up is desirable, these early results support the use of PS implants designed for increased flexion.

Biomechanical analysis and the study results of children’s with cerebral palsy (CP) muscles bioelectrical activity while walking on a flat surface are represented. Increased flexion in the hip and shoulder joints and extension in the elbow joint in children with cerebral palsy were observed, with the movement of the lower limbs had less smooth character in comparison with the control group. Herewith, the oscillation amplitude was significantly increased, and the frequency in the m. gastrocnemius and m. lateralis was decreased. It was shown, that the dynamic stereotype of walking in children with cerebral palsy was characterized by excessive involvement of m. gastrocnemius and m.latissimus dorsi in locomotion. Thus, resulting biomechanical and bioelectrical parameters of walking should be considered in the rehabilitation programs development.

Multiple factors are responsible for ACL tears. The key factor in the gender discrepancy appears to be dynamic, not static, and proximal, not distal. The factors involved in evaluating the female ACL are multiple. However, it is the dynamic movement patterns ot hip and knee position with increased flexion and a coordinated proximal muscle firing pattern to keep the body in a safe landing position that are the most critical factors. An ACL injury at an early age is a life-changing event. We can very successfully reconstruct and rehabilitate an ACL, but we cannot stop there. We must now go into the prevention arena. In the United States there is tremendous variation in the exposure and acquisition of skills of physical activities in our youth. Today, children are often playing inside, using computers and watching television-missing out on the opportunity to learn safe movement patterns. Therefore, physical movement classes should occur very early in life, teaching children to land safely and in control, similar to the cry of "get down, stay down" routinely heard during youth soccer. Similarly, specific strength training programs can address landing as well as foot movements during cutting in basketball. Coaches should issue stern warnings when athletes demonstrate a high-risk movement patterns such as one-leg landings, out-of-control baseline landings, or straight-leg landings. The warnings may serve to keep the athlete from "touching the hot stove again" for fear of getting burned. No athlete feels she will be the one to get injured. Therefore, prospective analysis is likely to be received more warmly by the athletes if the program is presented with an emphasis on performance improvement rather than injury prevention. With increased participation in these programs, multiple-center analysis will have the power necessary to determine which factors significantly predispose athletes to ACL injury. The future for injury prevention is bright. We must rise to the challenge.

Fetal arm posture was studied longitudinally in 10 uncomplicated pregnancies using real-time ultrasound. Observations were performed at four weekly intervals from 12 to 36 weeks, and at 38 weeks. The percentage of assessments with optimal visualization of elbow, wrist and fingers was 84% at 12 weeks and more than 90% thereafter (range 92-98%). There was a clear developmental trend towards increased flexion. Flexion of the elbow occurred frequently from 12 weeks onwards with an increased incidence at 16 weeks, that in the fingers from 20 weeks onwards and from 28 weeks to term age in the wrist. All three trends were statistically significant. There was considerable intra-individual consistency in terms of the ages at which flexion increased. In fact the increase of flexion occurred one session later in only 6/30 registrations. The combined data of the elbow, wrist and fingers revealed preferential arm posture at 12 weeks with the elbow flexed and the wrist and fingers extended. From 16 to 28 weeks, the predominant posture consisted of elbow flexion, wrist extension and finger flexion and complete flexion thereafter. The development of fetal arm posture does not comply with a proximo-distal trend in that there was first an increase in flexion at the elbow, followed by the fingers and finally the wrist. The implications of our findings for understanding the prenatal development of the central nervous system and subsequent postural adjustments to extrauterine life are discussed.

0.80 0.30 15.3 8.2 37.9 6.0 Cluster 9 0.9 0.2 13.6 5.2 0.61 0.40 33.3 6.4 39.0 8.8 involvement by showing a discrete foot drop during swing phase. The ankle of patients in cluster 3 was in plantar flexion during the main part of the gait cycle. Because of the characteristics this cluster was called reversed second ankle rocker with premature knee extension. Cluster 4, double bump with jump knee, was characterised by a double bump pattern at the ankle and an increased flexion at the hip (p4/1, 4/5, 4/7, 4/8 and 4/9 < 0.001) and the knee. Patients of cluster 5 were presented with a recurvatum knee. These children walked slower (significantly different between all clusters p < 0.001 except for cluster 9) compared to normal subjects, with a clearly decreased ankle power generation at push off (p5/1, 5/2, 5/3, 5/4, 5/6 and 5/7 < 0.001). Cluster 6 was characterised by a neutral to dorsiflexed ankle, with a double bump pattern in the sagittal plane. Therefore this cluster was called apparent equinus. Due to the reversed second ankle rocker, these patients had a large power absorption at the ankle at midstance (p6/2, 6/4, 6/7 and 6/8 < 0.001). Several features of cluster 6 indicated a stiff knee pattern and a flexed hip. Cluster 7, mild crouch, demonstrated an increased dorsiflexion at loading response (p7/1, 7/2, 7/3, 7/5 and 7/9 < 0.001). Also typical for this group was the increased knee flexion throughout the stance phase. The most outstanding feature of cluster 8 was the severe crouch pattern. Furthermore the ankle showed a lack of plantar flexion during the gait cycle (p8/2, 8/3, 8/5 and 8/9 < 0.0001). Patients in cluster 9 demonstrated continuous plantar flexion at the ankle and flexion at the hip and knee, and could therefore be described as a typical triple flexion pattern. The S.D. and mean of five important parameters were illustrated in Table 1.

The aim of the present study was to investigate changes in joint angles and limb positions accompanying postural control impairments induced by fatigue of the ankle plantarflexor muscles and vision removal. Thirteen subjects performed unipedal standing tasks with and without vision before and after isometric fatigue of the plantarflexor muscles. Results indicated that to compensate for the negative effects of fatigue and vision removal on postural control, participants increased flexion at the ankle, knee and back while the free lower limb and the pelvis moved backward and the upper limbs forward. These strategies could be performed to increase the role of non-fatigued muscles and optimize the use of all the joints implicated in unipedal standing.

A new method to study the reactions to unexpected mechanical perturbations during human walking on a treadmill is presented. Perturbations consisted of an obstruction of the forward swinging foot during the early swing phase. These were caused by obstacles which were dropped on the treadmill in front of the subject. The timing of the perturbation was controlled by an electromagnet which released the obstacle at a preprogrammed delay after left or right heel strike. This kind of perturbation evoked stumbling reactions. The electromyographic (EMG) responses during these stumbling reactions had mean latencies of 76 ms in both the ipsilateral biceps femoris and rectus femoris when perturbations were applied in early swing. During the perturbed swing, increased flexion in the knee occurred to lift the foot over the obstacle. Both the EMG and kinesiologic responses were reproducible when perturbations were presented in the same part of the swing phase of different step cycles.

In this experiment, we investigated the effects that mouse pad surface height and wrist support had on wrist posture. In a pointing task, 16 subjects moved a mouse-controlled cursor clockwise or counterclockwise around three fixed targets, which varied by size and distance depending on task condition. Wrist extension, flexion, radial deviation, and ulnar deviation data were collected via a wrist monitor attached to the right hand and forearm. The presence of a wrist support decreased wrist extension and radial deviation, and increased wrist flexion. Higher pad surface height resulted in increased flexion and ulnar deviation, and decreased extension and radial deviation. A comparison of the conditions which were at the same pad height, but differed due to the presence or absence of wrist support, revealed that wrist extension was reduced by the presence of a wrist support at all but the highest height.

Postoperative flexion is an important factor in the outcome of total knee arthroplasty. Although normal activities of daily living require a minimum of 105° to 110° of flexion, patients from non-Western cultures often engage in activities such as kneeling and squatting that require higher flexion. The desire to achieve greater flexion serves as the driving force for prosthetic modifications, including high-flexion designs. Techniques used to measure knee flexion and knee position during measurement are not often described or are different depending on the examiner. The purpose of this study was to compare active (self) and passive (assisted) flexion after successful total knee arthroplasty for 5 prostheses (2 standard and 3 high-flexion) using clinical (goniometer) and radiographic (true lateral radiograph) measurement techniques by different independent examiners. At a mean follow-up of 2.7 years (range, 1–5.6 years), a total of 108 patients (144 total knee arthroplasties) had completed the study. Mean postoperative active flexion was 111° clinically and 109° radiographically for the standard designs and 114° clinically and 117° radiographically for the high-flexion designs. Adding passive flexion increased flexion to 115° clinically and 117° radiographically for the standard designs and 119° clinically and 124° radiographically for the high-flexion designs. Flexion differences between the 2 measurement techniques (active vs passive and clinically vs radiographically) were statistically significant ( P

In posterior stabilised total knee replacement (TKR) a larger femoral component is sometimes selected to manage the increased flexion gap caused by resection of the posterior cruciate ligament. However, concerns remain regarding the adverse effect of the increased anteroposterior dimensions of the femoral component on the patellofemoral (PF) joint. Meanwhile, the gender-specific femoral component has a narrower and thinner anterior flange and is expected to reduce the PF contact force. PF contact forces were measured at 90°, 120°, 130° and 140° of flexion using the NexGen Legacy Posterior Stabilized (LPS)-Flex Fixed Bearing Knee system using Standard, Upsized and Gender femoral components during TKR. Increasing the size of the femoral component significantly increased mean PF forces at 120°, 130° and 140° of flexion (p = 0.005, p < 0.001 and p < 0.001, respectively). No difference was found in contact force between the Gender and the Standard components. Among the patients who had overhang of the Standard component, mean contact forces with the Gender component were slightly lower than those of the Standard component, but no statistical difference was found at 90°, 120°, 130° or 140° of flexion (p = 0.689, 0.615, 0.253 and 0.248, respectively). Upsized femoral components would increase PF forces in deep knee flexion. Gender-specific implants would not reduce PF forces.

This study examined the volitional and magnetically-evoked neuromuscular performance of the quadriceps femoris at functional knee joint angles adjacent to full extension. Indices of volitional and magnetically-evoked neuromuscular performance (N=15 healthy males, 23.5 ± 2.9 years, 71.5 ± 5.4 kg, 176.5 ± 5.5 cm) were obtained at 25°, 35° and 45° of knee flexion. Results showed that volitional and magnetically-evoked peak force (PF(V) and P(T)F(E), respectively) and electromechanical delay (EMD(V) and EMD(E), respectively) were enhanced by increased knee flexion. However, greater relative improvements in volitional compared to evoked indices of neuromuscular performance were observed with increasing flexion from 25° to 45° (e.g. EMD(V), EMD(E): 36% vs. 11% improvement, respectively; F([2,14])=6.8, p0.05). There were no significant correlations between EMD(V) and EMD(E) or PF(V) and P(T)F(E), at analogous joint positions. These findings suggest that the extent of the relative differential between volitional and evoked neuromuscular performance capabilities is joint angle-specific and not correlated with performance capabilities at adjacent angles, but tends to be smaller with increased flexion. As such, effective prediction of volitional from evoked performance capabilities at both analogous and adjacent knee joint positions would lack robustness.

OBJECTIVE: The aim of this study was to examine the influence of extensive work-related use of the feet on functional ankle stability among musicians. METHODS: Thirty professional organists were compared to professional pianists and controls. All participants completed a questionnaire. Range of motion (ROM), peroneal reaction time, and positional sense tests of the ankle were measured. The postural balance control was investigated with the Biodex Stability System for the stable level 8 and unstable level 2. Statistical analysis was done with the Kruskal-Wallis test, Mann-Whitney test with Bonferroni-Holm correction, and Fisher’s exact test. RESULTS: Nine of 30 organists compared to 5 of 30 pianists and controls reported ankle sprains in their medical history. Pianists had a significant increased flexion of both ankle joints compared to organists (p≤0.01) and increased flexion of the right ankle joint compared to controls (p=0.02). The positional sense test and postural balance control showed no significant differences among groups. The peroneal reaction time of the right peroneus longus muscle was significantly increased in pianists compared to controls (p=0.008). CONCLUSIONS: Organists have shown a high incidence of ankle sprains. Despite their extensive work-related use of the ankle joints, organists have neither increased functional ankle stability nor increased ROM of their ankle joints in comparison to controls. Pianists have increased flexion of the ankle joint, perhaps due to the exclusive motion of extension and flexion while using the pedals. To minimize injuries of the ankle and improve functional ankle stability as well as balance control, proprioceptive exercises of the ankle in daily training programs are recommended.

We generated patient-specific computer models of total knee arthroplasty from 10 patients to compute maximum flexion angle before implant-bone impingement. Motion was simulated for 5 different femoral implant positions and 11 different tibial insert positions at 4 different tibial posterior slopes. In the neutral position, the mean maximum flexion angle was 136.3°. The range because of anatomical variation among patients was 13.0°. A combination of 2-mm posterior translation of the femoral component with a 10-mm anterior translation of the insert and a 7° posterior slope increased flexion by a mean of 14° relative to the neutral position. The rate of change in flexion angle was 0.4°/mm to 1.5°/mm with respect to implant position and 1.5°/mm increase in the posterior condylar offset.

Flexion following total knee arthroplasty in the US population generally falls between 100° and 120°. Because of these relatively low flexion arcs, total knee arthroplasty prosthetic designs emerged allowing “high flexion” (≥125°). We hypothesized that a high-flexion implant design, Scorpio Non-Restrictive Geometry cruciate-retaining knee prosthesis, would allow clinical early maximum flexion of at least 125°. A prospective observational cohort study enrolled 87 unselected patients (94 knees) evaluated preoperation and 3 months and 1 year postoperation for clinical flexion, arc of motion, and Knee Society scores. At 1 year, 67% of knees had improved flexion and 23% achieved flexion of at least 125°. Clinically, flexion improved by 6.9° and total arc of motion improved by 10.6° from preoperation to 1-year postoperation. Although this high-flexion design allows increased flexion, many patients fail to achieve flexion of at least 125°.

A retrospective review of 23 patients after treatment of humeral fractures with hanging cast was performed. The average followup time was 8.59 years (range, 1.0 to 15.5 years). Functional results were good in eight (34.8%) and excellent in 15 patients (65.2%). To assess the flexibility of shoulder and elbow joints 24 parameters were measured on each body side using the neutral-zero method of Debrunner. A cumulative comparison of each parameter revealed decreased flexibilities of the upper limb after treatment with hanging cast: reduced abduction without moving shoulder blade (84.08 +/- 7.53 vs. 77.34 +/- 11.38; p less than 0.05), reduced free abduction (166.09 +/- 14.4 vs. 158.22 +/- 19.28; p less than 0.01), reduced anteelevation (155.26 +/- 10.12 vs. 149.35 +/- 3.22; p less than 0.01), reduced external rotation with hanging arm (48.96 +/- 19.05 vs. 41.18 +/- 16.75; p less than 0.01), increased flexion of the shoulder (25.65 +/- 10.37 vs 27.3 +/- 10.0; p less than 0.05) and reduced extension of the elbow (0.86 +/- 6.92 vs. -2.68 +/- 9.63; p less than 0.05). These findings show that longterm deficiencies of humeral mobility after treatment with hanging casts exist.

At our institution, we have used Endo-Model prostheses (Waldermar Link GmbH & Co, Hamburg, Germany) for difficult knee reconstructions. These rotating-hinge prostheses have an antidislocation feature that prevents dislocation due to distraction disengagement. In a series of 192 consecutive prostheses, we have identified 2 cases of femorotibial dislocations. An increased flexion laxity allows excessive distraction and hence implant dislocation after antidislocation feature loosening. To our knowledge, there are no other reports in the literature regarding dislocation of a rotating-hinge knee prosthesis with antidislocation design.

Mediolateral tibiofemoral alignment after knee replacements is considered an important clinical predictor. Weight-bearing radiographic examination has been proposed as the golden standard. Clinically the most reliable measurement is lying unstressed measurement of the mediolateral angle. The comparison made in this study showed poor correlation between clinical and radiological examinations. The reasons may be greater force put on the weight-bearing knee or increased flexion of the weight-bearing knee, which allow more laxity in the coronal plane and cause the knee to slip into the most unstable position. The symptomatic value of misalignment is questioned, but if weight-bearing radiographic examination should be used more specific operational instruction must be given than conventionally.

A significant number of injuries in the workplace is attributed to slips and falls. Biomechanical responses to actual slip events determine whether the outcome of a slip will be recovery or a fall. The goal of this study was to examine lower extremity joint moments and postural adjustments for experimental evidence of corrective strategies evoked during slipping in an attempt to prevent falling. Sixteen subjects walked onto a possibly oily vinyl tile floor, while ground reaction forces and body motion were recorded at 350 Hz. The onset of corrective reactions by the body in an attempt to recover from slips became evident at about 25% of stance and continued until about 45% into stance, i.e. on average between 190 and 350 ms after heel contact. These reactions included increased flexion moment at the knee and extensor activity at the hip. The ankle, on the other hand, acted as a passive joint (no net moment) during fall trials. Joint kinematics showed increased knee flexion and forward rotation of the shank in an attempt to bring the foot back towards the body. Once again, the ankle kinematics appeared to play a less dominant role (compared to the knee) in recovery attempts. This study indicates that humans generate corrective reactions to slips that are different than previously reported responses to standing perturbations translating the supporting surface.

(negative values indicate an increased flexion; there was no effect of the day of the week). On day 0 the median time the calves could stand on their claws without knuckling was 3·8 seconds (minimum 0 seconds, maximum 45 seconds). This was not significantly different on day 1 (median 3·8 seconds). Standing time increased to 6·8 seconds on day 2 and to 9·3 seconds on day 3, but decreased to 3·8 seconds on day 4 (all differences to day 0, P>0·05). The results do not suggest that the oxytetracycline infusions had an influence on the results of goniometry. Measurements 180 minutes after the infusion of oxytetracycline even yielded a minimal additional flexion, and the statistically significant slight extensions observed on days 3 and 4 must be considered as clinically irrelevant. The effects of oxytetracycline seen by Madison and others (1994) in foals may be due to the existence of myofibroblasts in the accessory ligaments of foals (Hartzel and others 2001). Madison and others (1994) assumed that oxytetracycline chelates calcium or decreases the expression of contractile proteins and therefore inhibits the ability of myofibroblasts to contract. To the authors’ knowledge myofibroblasts in the flexor tendons of calves have not yet been described. The slight extensions observed in the present study may be due to the repeated extensions of the tendons during goniometry. It is well known that slight flexions disappear within a few days without therapy if calves are able to stand on the tip of their claws. None of the calves was completely cured according to the authors’ definition. Laven and Cook (1997) described

The influence on motoric skills of surgical treatment of scoliosis in 14 children with myelomeningocele was studied. Fifty percent of the children had increased flexion contractures of the hips at follow-up, and all but one patient had impaired motor ability. There was no influence on activities of daily life, but 57% of children had lost some of their ambulation capacity. Postoperative physiotherapy is highly advisable. Intensive attempts to treat these children conservatively to prevent scoliosis progression is suggested.

VIBRATING benches are currently in use at Tudor House Nursery, Liverpool, to facilitate treatment of children under five years old who have cerebral palsy. Niagara therapy benches are robustly constructed and covered in flame retardant and easily cleaned vinyl. Rubber feet reduce transmitted vibration and prevent sliding. The vibration they provide is of variable frequency between 15-30 Hz, and has the physiological effect of reducing spasticity through muscle relaxation. The frequency is controlled by a switch sited underneath the bench, out of reach of little fingers. A separate hand-held unit houses the on/off control. The benches are 5 0 cm long. Their height and width are determined by the size of the users, and the manufacturer will supply to suit individual needs. The height should allow the children to sit comfortably with both feet flat on the floor, wi th hips and knees at right angles. As the children usually sit astride the benches, careful consideration must be given to their width, as excessive hip abduction would lead to increased flexion at the hips. To give an example of dimensions, one of the benches currently in use with children aged three to four years, is 18 cm high and 18 c m wide. The benches have now been in use at Tudor House for 2 ?h years, and have the following benefits

During a twelve-month period, 23 per cent of a series of knees undergoing total replacement were manipulated two weeks postoperatively to increase flexion. While manipulation achieved an immediate increase in flexion from a mean of 71 degrees to a mean of 108 degree, by one week after manipulation the mean flexion was reduced to 88 degrees. By one year postoperatively, the manipulated knees were found to have a range of motion similar to that of their non-manipulated counterparts. Such factors as preoperative flexion and diagnosis appear to be the major determinants of ultimate flexion, and they seem to offset the temporarily increased flexion afforded by manipulation. The primary reason for manipulation is to facilitate the postoperative rehabilitation program for patients with painful, limited motion of the knee.

We assessed the functional abilities of six patients who had had disarticulation of nine knees during childhood by analyzing their gait using electrocardiographic telemetry. Those who were more than five years old were further studied by timing them as they ran the fifty-yard (45.7-meter) dash and by testing the strength of the musculature of the hip girdle using a Cybex dynamometer. The physiological cost-index of Butler et al. was used to assess energy consumption. Three patients had had unilateral disarticulation and three had had bilateral disarticulation. Kinematic studies showed persistent bilateral abduction of the hip throughout the gait cycle in all six patients. The flexion-extension arc of the hip was decreased in the three who had had bilateral disarticulation. Increased flexion of the hip was noted on the normal side and decreased flexion, on the affected side in those who had had unilateral disarticulation. Phase reversal of pelvic obliquity was noted in the amputees who had had bilateral disarticulation. The prosthetic knee showed good flexion during the swing phase. All patients showed a mild decrease in the velocity of gait and in the length of step and stride. The patients who had had unilateral disarticulation showed decreased duration of the bilateral stance and single stance phases and increased duration of the swing phase. Those who had had bilateral disarticulation of the knee had a normal distribution of the components of the gait cycle: bilateral stance, single stance, and swing. The physiological cost-index for all six was within the normal range, indicating minimum energy handicap.(ABSTRACT TRUNCATED AT 250 WORDS)

Flexion, abduction, and external rotation of the hip joint were recorded in 30 volunteers randomized into three groups of 10. The measurements were taken before, immediately after, and 30 minutes after treatment of heat, stretching and a combination of heat plus stretching. Heat only did not improve the range of motion of the hip joint. Stretching increased flexion and external rotation, and heat plus stretching in combination gave the greatest increase in flexion motion, and also significantly increased abduction. External rotation after stretching treatment, and flexion and abduction after heat plus stretching treatment were still significantly increased after 30 minutes.J Orthop Sports Phys Ther 1984;6(2):110-115.

“V” shaped widening of the predens space (PDS) in flexion can be a worrisome finding in trauma patients, possibly representing injury to the transverse ligament. These patients may also show widening of the C-1/C-2 interspinous distance. We think this appearance is usually due to increased flexion mobility at the atlantoaxial level with developmental elongation or laxity of the cranial end of the transverse ligament and/or the posterior ligamentous complex. Tearing of only the cranial end of the transverse ligament must be extremely rare, if it occurs at all; there is no reported proven case. Tearing of only posterior ligaments seems possible and should be evaluated clinically.

New specimens of Plio-Pleistocene Australopithecus boisei are described from east and west Lake Turkana in Northern Kenya. These include a cranium and partial mandible from deposits close to 2.5 Myr and two partial crania and two mandibles from later horizons. The earlier fossils enable us to decipher, for the first time, some of the in situ evolution of this species within the Turkana Basin. The following are among the important changes in the cranium through time: 1) increase in size and change in shape of the braincase, 2) changes in the meningeal vessel pattern and possibly in the venous drainage pattern, 3) increased flexion of the cranial base and decreased prognathism, and 4) changes in the temporal bone to bring about a more vertical posterior face of the petrous pyramid and the development of a strong articular eminence.

Twenty-four cases of vertebral column injuries associated with tobogganing accidents are presented. The position assumed by the participants increased flexion of the vertebral column, therefore enhancing the possibility of injury to the spine, especially at the mobile thoracolumbar junction. The importance of a thorough examination in evaluating these patients is emphasized as not all injuries are benign. We urge safer and better organization of tobogganing facilities. Two case reports, one a burst fracture of L1 with neurologic involvement and the second, a traumatic spondylolisthesis of L1, are presented in detail.