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Background: The company Ethnocare has developed the Overlay, a new pneumatic solution for managing volumetric variations (VVs) of the residual limb (RL) in transtibial amputees (TTAs), which improves socket fitting. However, the impact of the Overlay during functional tasks and on the comfort and pain felt in the RL is unknown. Methods: 8 TTAs participated in two evaluations, separated by two weeks. We measured compensatory strategies (CS) using spatio-temporal parameters and three-dimensional lower limb kinematics and kinetics during gait and sit-to-stand (STS) tasks. During each visit, the participant carried out our protocol while wearing the Overlay and prosthetic folds (PFs), the most common solution to VV. Between each task, comfort and pain felt were assessed using visual analog scales. Results: While walking, the cadence with the Overlay was 105 steps/min, while it was 101 steps/min with PFs (p = 0.021). During 35% and 55% of the STS cycle, less hip flexion was observed while wearing the Overlay compared to PFs (p = 0.004). We found asymmetry coefficients of 13.9% with the Overlay and 17% with PFs during the STS (p = 0.016) task. Pain (p = 0.031), comfort (p = 0.017), and satisfaction (p = 0.041) were better with the Overlay during the second visit. Conclusion: The Overlay's impact is similar to PFs' but provides less pain and better comfort. [ABSTRACT FROM AUTHOR]

Inertial measurement units and normative values enable clinicians to quantify clinical walking tests and set rehabilitation goals. Objectives of this study were (1) to compare time- and distance-based walking tests in individuals with lower limb amputation (iLLA) and normative values following rehabilitation discharge (T1) and 6 weeks after discharge (T2) and (2) to investigate spatiotemporal and foot kinematic parameters over a 6-minute walk test using inertial measurement units. Twelve iLLA participated in this study. Distance, cadence, stance ratio, loading rate ratio, push-up ratio, path length, and minimum toe clearance were analyzed during 6-minute walk test. Nonparametric repeated-measures analysis of variance tests, Bonferroni corrections, were performed. Time of distance-based walking tests diminished at T2 (P < .02). Compared with normative values, walking performance in iLLA was reduced. Cadence at T2 increased significantly (P = .026). Stance ratio increased in both legs at T2 (P < .05). Push-up ratio tended to decrease at T2 in the amputated leg (P = .0003). Variability of path length and minimum toe clearance at T2 were less than at T1 in the nonamputated leg (P < .05). Spatiotemporal improvement at T2 could be due to prosthesis adaptation in iLLA. The lower performance of the functional walk test compared with normative values could be due to amputation and pain-related fatigue. [ABSTRACT FROM AUTHOR]

Diabetes peripheral neuropathy (DPN) leads to balance impairment among diabetes mellitus (DM). The aims of this study were to (1) distinguish between DM patients who have/do not have DPN and to (2) compare quadriceps' strength and balance performance of DM, DPN, and healthy groups. Fifteen healthy females and 33 females with type 2 diabetic patients participated. The electrodiagnostic method was used to classify diabetic patients into DM and DPN. A dynamometer was used to measure quadriceps' strength. Single-leg standing on a force plate was also used to quantify participants' balance. Smaller conduction velocity and amplitude and greater distal latency of all nerves were observed in the DPN compared with the DM in particular for sensory nerve. In DPN, conduction velocity was asymmetrical. The quadriceps' strength of both legs in DPN and the right leg in DMwas smaller than in the control group. The root mean square of the center of pressure was similar between DMand DPN. But it was larger in DPN than in the control group. DPN is associated with asymmetrical conduction velocity, smaller quadriceps' strength, and weaker balance performance that is suggestive of higher risk of falling. Balance training is recommended for the DPN group during their rehabilitation to reduce their falling risk. [ABSTRACT FROM AUTHOR]

Altered tibiofemoral contact forces represent a risk factor for osteoarthritis onset and progression, making optimization of the knee force distribution a target of treatment strategies. Musculoskeletal model-based simulations are a state-of-the-art method to estimate joint contact forces, but they typically require laboratory-based input and skilled operators. To overcome these limitations, ambulatory methods, relying on inertial measurement units, have been proposed to estimated ground reaction forces and, consequently, knee contact forces out-of-the-lab. This study proposes the use of a full inertial-capture-based musculoskeletal modelling workflow with an underlying probabilistic principal component analysis model trained on 1787 gait cycles in patients with knee osteoarthritis. As validation, five patients with knee osteoarthritis were instrumented with 17 inertial measurement units and 76 opto-reflective markers. Participants performed multiple overground walking trials while motion and inertial capture methods were synchronously recorded. Moderate to strong correlations were found for the inertial capture-based knee contact forces compared to motion capture with root mean square error between 0.15 and 0.40 of body weight. The results show that our workflow can inform and potentially assist clinical practitioners to monitor knee joint loading in physical therapy sessions and eventually assess long-term therapeutic effects in a clinical context. [ABSTRACT FROM AUTHOR]

Segmenting the gait cycle into multiple phases using gait event detection (GED) is a well-researched subject with many accurate algorithms. However, the algorithms that are able to perform accurate and robust GED for real-life environments and physical diseases tend to be too complex for their implementation on simple hardware systems limited in computing power and memory, such as those used in wearable devices. This study focuses on a numerical implementation of a reservoir computing (RC) algorithm called the echo state network (ESN) that is based on simple computational steps that are easy to implement on portable hardware systems for real-time detection. RC is a neural network method that is widely used for signal processing applications and uses a fast-training method based on a ridge regression adapted to the large quantity and variety of IMU data needed to use RC in various real-life environment GED. In this study, an ESN was used to perform offline GED with gait data from IMU and ground force sensors retrieved from three databases for a total of 28 healthy adults and 15 walking conditions. Our main finding is that despite its low complexity, ESN is robust for GED, with performance comparable to other state-of-the-art algorithms. Our results show the ESN is robust enough to obtain good detection results in all conditions if the algorithm is trained with variable data that match those conditions. The distribution of the mean absolute errors (MAE) between the detection times from the ESN and the force sensors were between 40 and 120 ms for 6 defined gait events (95th percentile). We compared our ESN with four different state-of-the-art algorithms from the literature. The ESN obtained a MAE not more than 10 ms above three other reference algorithms for normal walking indoor and outdoor conditions and yielded the 2nd lowest MAE and the 2nd highest true positive rate and specificity when applied to outdoor walking and running conditions. Our work opens the door to using the ESN as a GED for applications in wearable sensors for long-term patient monitoring. [ABSTRACT FROM AUTHOR]

For individuals with altered sensory cues, vibrotactile feedback improves their balance control. However, should vibrotactile feedback be provided every time balance control is compromised, or only one-third of the time their balance is compromised? We hypothesized that vibrotactile feedback would improve balance control more when provided every time their balance is compromised. Healthy young adults were randomly assigned to two groups: group 33% feedback (6 males and 6 females) and group 100% feedback (6 males and 6 females). Vibrotactile feedbacks related to the body's sway angle amplitude and direction were provided, while participants stood upright on a foam surface with their eyes closed. Then, we assessed if balance control improvement lasted when the vibrotactile feedback was removed (i.e., post-vibration condition). Finally, we verified whether or not vibrotactile feedback unrelated to the body's sway angle and direction (sham condition) altered balance control. The results revealed no significant group difference in balance control improvement during vibrotactile feedback. Immediately following vibrotactile feedback, both groups reduced their balance control commands; body sway velocity and the ground reaction forces variability decreased. For both groups, unrelated vibrotactile feedback worsened balance control. These results confirmed that participants processed and implemented vibrotactile feedback to control their body sways. Less vibrotactile feedback was effective in improving balance control. [ABSTRACT FROM AUTHOR]

Purpose: The biomechanical impact of undergoing a single-event multilevel surgery (SEMLS) for children with cerebral palsy (CP) presenting an intoeing gait pattern has been widely documented. However, past studies mostly focused on gait quality rather than efficiency. Thus, there is a need to determine the impact of undergoing a SEMLS on gait quality and efficiency in children with CP presenting an intoeing gait pattern. Methods: Data from 16 children with CP presenting an intoeing gait pattern who underwent a SEMLS were retrospectively selected. Gait kinematics was quantified before (baseline) and at least 1 year after the surgery (follow-up). Gait quality was investigated with the Gait Profile Score (GPS), hip internal rotation angle and foot progression angle (FPA). Gait efficiency was analysed using clinically accessible variables, namely the normalised gait speed and medio-lateral and vertical centre of mass excursions (COMp). Dependent variables were compared between sessions with paired t-tests. Results: At the follow-up, children with CP exhibited a more outward FPA and GPS as well as a decreased hip internal rotation angle. No changes in normalised gait speed and vertical COMp excursion were observed, and medio-lateral COMp excursion was slightly decreased. Conclusion: Children with CP presenting an intoeing gait pattern who underwent a SEMLS exhibited an increased gait quality, but gait efficiency was only minimally improved at the follow-up compared to baseline. Further studies are needed to identify contributors of gait efficiency in children with CP, and the best treatment modalities to optimise both their gait quality and efficiency. [ABSTRACT FROM AUTHOR]

Background: The 6-minute walk test (6MWT) is one of the common clinical tests to assess rehabilitation progress and needs in individuals with lower-limb amputation (iLLAs). However, the analysis of this test is mostly limited to the distance parameter. The first aim was to investigate effort intensity and spatiotemporal parameters of 6MWT in iLLAs using inertial measurement units (IMUs) and heart rate (HR) monitor, and second, to assess physical, physiological, and pain-related aspects of fatigue over 6MWT. Methods: Eleven unilateral iLLAs (57.91±15.63 years old) participated in this study. To evaluate HR and spatiotemporal parameters over 6MWT, data were classified using 6 intervals of 1 minute each (I1-I6). The pain level of participants was estimated using the visual analog scale (VAS). Results: Our results showed that the means of normalized HR gradually increased over 6MWT (I1: 61.59±10.73 HRmax%, I6: 70.15±12.26 HRmax%, P =.003). Variability of HR during the first interval of 6MWT was higher than the others (P <.05). The stance ratio of the gait cycle increased over 6MWT (P <.05). Cadence and speed decreased over 6MWT (P <.05). VAS score after 6MWT was significantly higher than before 6MWT (P =.016). Conclusion: In this preliminary study, effort intensity over 6MWT gradually increased because of enhancement of HR. Deterioration of speed and cadence and enhancement of stance ratio over 6MWT imply potential physical aspects of fatigue and instability. Level of Evidence: Level III, retrospective comparative study. [ABSTRACT FROM AUTHOR]

Context: Decreased flexibility in muscles and joints of lower extremities is commonly observed in runners. Understanding the effect of decreased flexibility on knee walking kinematics in runners is important because, over time, altered gait patterns can make runners vulnerable to overuse injuries or degenerative pathologies. Objectives: To compare hamstring and iliotibial-band (ITB) flexibility and knee kinematics in runners and nonrunners. Design: A descriptive, comparative laboratory study. Setting: Hamstring and ITB flexibility were measured with the active knee-extension test and the modified Ober test, respectively, in both groups of participants. Three-dimensional (3D) walking kinematic data were then recorded at the knee using a motion-tracking system. Participants: 18 runners and 16 nonrunners. Main Outcome Measures: Knee-extension angle (hamstring flexibility) and hip-adduction angle (ITB flexibility). Knee kinematic parameters of interest included knee angle at initial contact, peak knee angles, and knee-angle range in all planes of movement. Results: The runners had a significantly less flexible ITB than the nonrunners (hip adduction [-] and adduction [+] angles, 3.1° ± 5.6° vs -6.4° ± 4.5°; P < .001). The runners demonstrated a greater mean tibial external-rotation angle at initial contact (7.3° ± 5.8° vs 2.0° ± 4.0°; P = .01) and a smaller mean peak tibial internal-rotation angle (-1.6° ± 3.0° vs -4.2° ± 3.2°; P = .04) than the nonrunners. Conclusion: This study provides new insight into the relationship between muscle flexibility and 3D knee kinematics in runners. This supports the premise that there is an association between muscle flexibility and transverse-plane knee kinematics in this population. [ABSTRACT FROM AUTHOR]

Context: Decreased flexibility in muscles and joints of lower extremities is commonly observed in runners. Understanding the effect of decreased flexibility on knee walking kinematics in runners is important because, over time, altered gait patterns can make runners vulnerable to overuse injuries or degenerative pathologies. Objectives: To compare hamstring and iliotibial-band (ITB) flexibility and knee kinematics in runners and nonrunners. Design: A descriptive, comparative laboratory study. Setting: Hamstring and ITB flexibility were measured with the active knee-extension test and the modified Ober test, respectively, in both groups of participants. Three-dimensional (3D) walking kinematic data were then recorded at the knee using a motion-tracking system. Participants: 18 runners and 16 nonrunners. Main Outcome Measures: Knee-extension angle (hamstring flexibility) and hip-adduction angle (ITB flexibility). Knee kinematic parameters of interest included knee angle at initial contact, peak knee angles, and knee-angle range in all planes of movement. Results: The runners had a significantly less flexible ITB than the nonrunners (hip adduction [-] and adduction [+] angles, 3.1° ± 5.6° vs -6.4° ± 4.5°; P < .001). The runners demonstrated a greater mean tibial external-rotation angle at initial contact (7.3° ± 5.8° vs 2.0° ± 4.0°; P = .01) and a smaller mean peak tibial internal-rotation angle (-1.6° ± 3.0° vs -4.2° ± 3.2°; P = .04) than the nonrunners. Conclusion: This study provides new insight into the relationship between muscle flexibility and 3D knee kinematics in runners. This supports the premise that there is an association between muscle flexibility and transverse-plane knee kinematics in this population. [ABSTRACT FROM AUTHOR]

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Background: The International Committee of the Red Cross supports a worldwide program of prosthetic fitting and rehabilitation. In this context, a prosthetic foot was developed and widely distributed in least developed countries.Study Design: Prospective, randomized, double-blind, controlled study.Objective: To compare patient satisfaction and energy expenditure during ambulation between a low-cost prosthetic foot designed with a polypropylene keel (CR-Equipements™ solid ankle cushion heel, International Committee of the Red Cross) to a well-recognized solid ankle cushion heel foot with a wooden keel (solid ankle cushion heel foot, Otto Bock).Methods: A total of 15 participants with unilateral transtibial amputation were evaluated using the two prosthetic feet in a randomized prospective double-blind crossover study. Main outcomes were patient satisfaction questionnaires (Satisfaction with Prosthesis Questionnaire and prosthetic foot satisfaction) and energy expenditure (oxygen consumption-mL/kg/min, oxygen cost-mL/kg/m, and heart rate-bpm).Results: There were no significant differences between the two prosthetic feet for satisfaction and energy expenditure.Conclusion: The low-cost solid ankle cushion heel foot with polypropylene keel provides comparable satisfaction and similar energy expenditure as the solid ankle cushion heel foot with wooden keel. Clinical relevance The results of this study support the application and widespread use of the CR-Equipements™ solid ankle cushion heel foot. From a cost-effectiveness standpoint, patients are well satisfied and exhibit similar outcomes at a substantially lower cost. [ABSTRACT FROM AUTHOR]

Background: The significance of subclinical vitamin D deficiency in the pathogenesis of fractures in children and adolescents currently remains unclear. Objective: We aimed to determine the prevalence of vitamin D insufficiency and its effect on bone mineral density (BMD) and bone mineral content (BMC) values in a collective of Swiss Caucasian children with a first episode of appendicular fracture. Design and methods: One hundred teenagers with a first episode of appendicular fracture [50 upper limb fractures (group 1) and 50 lower limb fractures (group 2)] and 50 healthy controls (group 3) were recruited into a cross-sectional study. The BMC and BMD values were measured by dual-energy X-ray absorptiometry, and serum 25 hydroxyvitamin D [25(OH)D] was assessed by electrochemiluminescence immunoassays. Results: From the 100 injured teenagers in the study, 12 % had deficient vitamin D levels (<20 ng/mL; <50 nmol/L) and 36 % had insufficient levels (≥20 <30 ng/mL; ≥50 <78 nmol/L), whereas 6 and 34 % of healthy controls were, respectively, vitamin D deficient and insufficient. There were no significant differences for serum 25(OH)D levels, L2-L4 BMD Z-score, and L2-L4 BMC Z-score variables ( p = 0.216) between the three groups nor for the calcaneal BMD Z-score variables ( p = 0.278) between healthy controls and lower limb fracture victims. Investigations on the influences of serum 25(OH)D on BMD and BMC showed no correlation between serum 25(OH)D and L2-L4 BMD Z-scores ( r = −0.15; p = 0.135), whereas low but significant inverse correlations were, surprisingly, detected between serum 25(OH)D and calcaneal BMD Z-scores ( r = −0.21; p = 0.034) and between serum 25(OH)D and L2-L4 BMC Z-scores ( r = −0.22; p = 0.029). Conclusions: A significant proportion of Swiss Caucasian teenagers were vitamin D insufficient, independent of limb fracture status, in our study. However, this study failed to show an influence of low vitamin D status on BMD and/or BMC of the lumbar spine and heel. [ABSTRACT FROM AUTHOR]

The aim of this study is to quantify the changes in the sagittal alignment of the cervical spine in patients with adolescent idiopathic scoliosis following posterior spinal fusion. Patients eligible for study inclusion included those with a diagnosis of mainly thoracic adolescent idiopathic scoliosis treated by means of posterior multisegmented hook and screw instrumentation. Pre and post-operative anterior-posterior and lateral radiographs of the entire spine were reviewed to assess the changes of cervical sagittal alignment. Thirty-two patients (3 boys, 29 girls) met the inclusion criteria for the study. The average pre-operative cervical sagittal alignment (CSA) was 4.0° ± 12.3° (range −30° to 40°) of lordosis. Postoperatively, the average CSA was 1.7° ± 11.4° (range −24° to 30°). After surgery, it was less than 20° in 27 patients (84.4%) and between 20° and 40° in 5 patients (15.6%). The results of the present study suggest that even if rod precontouring is performed and postoperative thoracic sagittal alignment is restored, improved or remains unchanged after significant correction of the deformity on the frontal plane, the inherent rigidity of the cervical spine limits changes in the CSA as the cervical spine becomes rigid over time. [ABSTRACT FROM AUTHOR]

The aim of this study is to describe the radiological changes in rib-vertebral angles (RVAs), rib-vertebral angle differences (RVADs), and rib-vertebral angle ratios (RVARas) in patients with untreated right thoracic adolescent idiopathic scoliosis and to compare with the normal subjects. The concave and convex RVA from T1 to T12, the RVADs and the RVARas were measured on AP digital radiographs of 44 female patients with right convex idiopathic scoliosis and 14 normal females. Patients were divided into three groups: normal subjects (group 1), scoliotic patients with Cobb's angle equal or <30° (group 2) and scoliotic patients with Cobb's angle over 30° (group 3). Overall values (mean ± SD) of the RVAs on the concave side were 90.5° ± 17° in group 1, 90.3° ± 15.8° in group 2 and 88.8° ± 15.4° in group 3. On the convex side, values were 90.0° ± 17.3° in group 1, 86.3° ± 13.7° in group 2 and 80.7° ± 14.4° in group 3. Overall values (mean ± SD) of the RVADs at all levels were 0.5° ± 0.7° in group 1, 4.0° ± 4.8° in group 2 and 8.0° ± 4.0° in group 3. The RVARa values (mean ± SD) at all levels was 1.008° ± 0.012° in group 1, 1.041° ± 0.061° in group 2 and 1.102° ± 0.151° in group 3. RVAD and RVARa values in the scoliotic segment were greater in patients with untreated scoliosis over 30° than in patients with an untreated deformity of <30° or normal subjects. A significant effect between groups was observed for the RVA, RVAD and RVARa variables. Measurement of RVA, RVAD and RVARa should not only be performed at and around the apex of a thoracic spinal deformity, but also extended to the whole thoracic spine. [ABSTRACT FROM AUTHOR]

This study presents a new method to estimate 3-D linear accelerations at tibia! and femoral functional coordinate systems. The method combines the use of 3-D accelerometers, 3-D gyroscopes and reflective markers rigidly fixed on an exoskeleton and, a functional postural calibration method. Marker positions were tracked by a six-camera optoelectronic system (VICON 460, Oxford Metrics). The purpose of this study was to determine if this method could discriminate between media! osteoarthritic and asymptomatic knees during gait. Nine patients with osteoarthritic knees and nine asymptomatic control subjects were included in this study. Eighteen parameters representing maximal, minimal, and range of acceleration values were extracted during the loading and preswing to mid-swing phase periods, and were compared in both groups. Results show good discriminative capacity of the new method. Eight parameters were significantly different between both groups. The proposed method has the potential to be used in comprehending and monitoring gait strategy in patients with osteoarthritic knee. [ABSTRACT FROM AUTHOR]

The purpose of this study is twofold: (1) to develop a classification method to distinguish between asymptomatic (AS) and knee osteoarthritis (OA) gait patterns using ground reaction force (GRF) measurements, and (2) to investigate OA severity within OA gait patterns. Features were first extracted from the GRF vectors to be used for classification. We investigated a two-level hierarchical classification and analysis method using the nearest neighbor rule. At the first level, the GRF data were classified into two classes: AS and OA. At the second level, the GRF data of OA patients were classified according to the pathology severity. The OA patients were grouped into two OA severity categories according to the Kellgren and Lawrence (KL) scale: KL 1 and KL 2 for one category, and KL 3 and KL 4 for the other. Experiments were conducted using data of 42 cases, 16 AS and 26 pathological. The method discriminated between AS and OA subjects with an accuracy of 38 of 42 cases, and assessed the severity correctly with an accuracy of 20 of 26 cases. These results demonstrated the validity of both, the feature and the classifier, for automatic classification of AS and knee OA gait patterns and for analysis of OA severity. [ABSTRACT FROM AUTHOR]

The aim of this work is to develop an automatic computer method to distinguish between asymptomatic (AS) and osteoarthritis (OA) knee gait patterns using 3-D ground reaction force (GRE) measurements. GRE features are first extracted from the force vector variations as a function of time and then classified by the nearest neighbor rule. We investigated two different features: the coefficients of a polynomial expansion and the coefficients of a wavelet decomposition. We also analyzed the impact of each GRF component (vertical, anteroposterior, and medial lateral) on classification. The best discrimination rate (91%) was achieved with the wavelet decomposition using the anteroposterior and the medial lateral components. These results demonstrate the validity of the representation and the classifier for automatic classification of AS and OA knee gait pat- terns. They also highlight the relevance of the anteroposterior and medial lateral force components in gait pattern classification. [ABSTRACT FROM AUTHOR]