The Gait Deviation Index: a new comprehensive index of gait pathology

Anomalous gait feature classification from 3-D motion capture data

The gait kinematics of an individual is affected by various factors, including age, anthropometry, gender, and disease. Detecting anomalous gait features aids in the diagnosis and treatment of gait-related diseases. The objective of this study was to develop a machine learning method for automatically classifying five anomalous gait features, i.e., toe-out, genu varum, pes planus, hindfoot valgus, and forward head posture features, from three-dimensional data on gait kinematics. Gait data and gait feature labels of 488 subjects were acquired. The orientations of the human body segments during a gait cycle were mapped to a low-dimensional latent gait vector using a variational autoencoder. A two-layer neural network was trained to classify five gait features using logistic regression and calculate an anomalous gait feature vector (AGFV). The proposed network showed balanced accuracies of 82.8% for a toe-out, 85.9% for hindfoot valgus, 80.2% for pes planus, 73.2% for genu varum, and 92.9% for forward head posture when the AGFV was rounded to the nearest zero or 1. Multiple anomalous gait features were detectable using the proposed method, which has a practical advantage over current gait indices, including the gait deviation index with a single value. The overall results confirmed the feasibility of using the proposed method for screening subjects with anomalous gait features using three-dimensional motion capture data.

Evaluation of Gait Pattern and Lower Extremity Kinematics of Children with Morquio Syndrome (MPS IV)

Morquio syndrome (mucopolysaccharidosis IV/MPS IV) is a genetic disorder leading to skeletal abnormalities and gait deviations. Research on the gait patterns and lower extremity physical characteristics associated with skeletal dysplasia in children with MPS IV is currently limited. This research aimed to provide baseline gait patterns and lower limb skeletal alignment of children with MPS IV utilizing three-dimensional instrumented gait analysis. This Institutional Review Board-approved retrospective study evaluates the kinematics of the lower extremities of children with MPS IV during gait, comparing them with an age-matched group of typically developing children. Thirty-three children with MPS IV were included (8.6 ± 4.0 years old). Children with MPS IV walk with increased anterior pelvic tilt, knee valgus, knee flexion, external tibial torsion, and reduced walking speed and stride length (p < 0.001). Multiplanar abnormal alignment results in abnormal knee moments (p < 0.001). Limited correlations exist (r = 0.69–0.28) between dynamic three-dimensional measurements of knee varus/valgus and rotational alignment and traditional static two-dimensional measures (physical examination or radiographs) suggesting the possibility of knee instability during gait and the benefits of dynamic assessment.

Effects of lower extremity constraint-induced movement therapy on gait and balance of chronic hemiparetic patients after stroke: description of a study protocol for a randomized controlled clinical trial

BACKGROUND

Protocols involving intensive practice have shown positive outcomes. Constraint induced movement therapy (CIT) appears to be one of the best options for better outcomes in upper limb rehabilitation, but we still have little data about lower extremity constraint-induced movement therapy (LE-CIT) and its effects on gait and balance.

OBJECTIVE

To evaluate the effects of an LE-CIT protocol on gait functionality and balance in chronic hemiparetic patients following a stroke.

METHODS

The study adopts a randomized, controlled, single-blinded study design. Forty-two patients, who suffered a stroke, who were in the chronic phase of recovery (>6 months), with gait disability (no community gait), and who were able to walk at least 10 m with or without the advice or support of 1 person, will be randomly allocated to 2 groups: the LE-CIT group or the control group (intensive conventional therapy). People will be excluded if they have speech deficits that render them unable to understand and/or answer properly to evaluation scales and exercises selected for the protocol and/or if they have suffered any clinical event between the screening and the beginning of the protocol. Outcome will be assessed at baseline (T0), immediately after the intervention (T1), and after 6 months (T2). The outcome measures chosen for this trial are as follows: 6-min walk test (6minWT), 10-m walk test (10mWT), timed up and go (TUG), 3-D gait analysis (3DGA), Mini Balance Evaluation Systems Test (Mini-BESTest), and as a secondary measure, Lower Extremity Motor Activity Log will be evaluated (LE-MAL). The participants in both groups will receive 15 consecutive days of daily exercise. The participants in the LE-CIT group will be submitted to this protocol 2.5 h/day for 15 consecutive days. It will include (1) intensive supervised training, (2) use of shaping as strategy for motor training, and (3) application of a transfer package (plus 30 min). The control group will receive conventional physiotherapy for 2.5 h/day over 15 consecutive days (the same period as the CIT intervention). Repeated measures analyses will be made to compare differences and define clinically relevant changes between groups.

RESULTS

Data collection is currently on-going and results are expected in 2021.

DISCUSSION

LE-CIT seems to be a good protocol for inclusion into stroke survivors' rehabilitation as it has all the components needed for positive results, as well as intensity and transference of gains to daily life activities.

TRIAL REGISTRATION

www.ensaiosclinicos.gov.br RBR-467cv6 . Registered on 10 October 2017. "Effects of Lower Extremities - Constraint Induced Therapy on gait and balance function in chronic hemipretic post-stroke patients".

Sparse Visual-Inertial Measurement Units Placement for Gait Kinematics Assessment

This study investigates the possibility of estimating lower-limb joint kinematics and meaningful performance indexes for physiotherapists, during gait on a treadmill based on data collected from a sparse placement of new Visual Inertial Measurement Units (VIMU) and the use of an Extended Kalman Filter (EKF). The proposed EKF takes advantage of the biomechanics of the human body and of the investigated task to reduce sensor inaccuracies. Two state-vector formulations, one based on the use of constant acceleration model and one based on Fourier series, and the tuning of their corresponding parameters were analyzed. The constant acceleration model, due to its inherent inconsistency for human motion, required a cumbersome optimisation process and needed the a-priori knowledge of reference joint trajectories for EKF parameters tuning. On the other hand, the Fourier series formulation could be used without a specific parameters tuning process. In both cases, the average root mean square difference and correlation coefficient between the estimated joint angles and those reconstructed with a reference stereophotogrammetric system was 3.5deg and 0.70, respectively. Moreover, the stride lengths were estimated with a normalized root mean square difference inferior to 2% when using the forward kinematics model receiving as input the estimated joint angles. The popular gait deviation index was also estimated and showed similar results very close to 100, using both the proposed method and the reference stereophotogrammetric system. Such consistency was obtained using only three wireless and affordable VIMU located at the pelvis and both heels and tracked using two affordable RGB cameras. Being further easy-to-use and suitable for applications taking place outside of the laboratory, the proposed method thus represents a good compromise between accurate reference stereophotogrammetric systems and markerless ones for which accuracy is still under debate.

Gait kinematic alterations in subjects with adult spinal deformity and their radiological determinants

BACKGROUND

Adults with spinal deformity (ASD) are known to have postural malalignment affecting their quality of life. Classical evaluation and follow-up are usually based on full-body static radiographs and health related quality of life questionnaires. Despite being an essential daily life activity, formal gait assessment lacks in clinical practice.

RESEARCH QUESTION

What are the main alterations in gait kinematics of ASD and their radiological determinants?

METHODS

52 ASD and 63 control subjects underwent full-body 3D gait analysis with calculation of joint kinematics and full-body biplanar X-rays with calculation of 3D postural parameters. Kinematics and postural parameters were compared between groups. Determinants of gait alterations among postural radiographic parameters were explored.

RESULTS

ASD had increased sagittal vertical axis (SVA:34 ± 59 vs -5 ± 20 mm), pelvic tilt (PT:19 ± 13 vs 11 ± 6°) and frontal Cobb (25 ± 21 vs 4 ± 6°) compared to controls (all p < 0.001). ASD displayed decrease walking speed (0.9 ± 0.3 vs 1.2 ± 0.2 m/s), step length (0.58 ± 0.11 vs 0.64 ± 0.07 m) and increased single support (0.45 ± 0.05 vs 0.42 ± 0.04 s). ASD walked with decreased hip extension in stance (-3 ± 10 vs -7 ± 8°), increased knee flexion at initial contact and in stance (10 ± 11 vs 5 ± 10° and 19 ± 7 vs 16 ± 8° respectively), and decreased knee flexion/extension ROM (55 ± 9 vs 59 ± 7°). ASD had increased trunk flexion (12 ± 12 vs 6 ± 11°) and reduced dynamic lumbar lordosis (-11 ± 12 vs -15 ± 7°, all p < 0.001). Sagittal knee ROM, walking speed and step length were negatively determined by SVA; lack of lumbar lordosis during gait was negatively determined by radiological lumbar lordosis.

SIGNIFICANCE

Static compensations in ASD persist during gait, where they exhibit a flexed attitude at the trunk, hips and knees, reduced hip and knee mobility and loss of dynamic lordosis. ASD walked at a slower pace with increased single and double support times that might contribute to their gait stability. These dynamic discrepancies were strongly related to static sagittal malalignment.

Bilateral asymmetry in the gait deviation index in school-aged children with the trait of developmental coordination disorder

BACKGROUND

Although previous studies have identified asymmetry in gait parameters in children with developmental coordination disorder (DCD), they have not investigated whether these findings coexist with asymmetry in gait quality, as represented by the gait deviation index (GDI).

RESEARCH QUESTION

This study sought to measure gait symmetry in children with traits of DCD (DCD trait) to elucidate the characteristic gait pattern.

METHODS

This study included 172 (82 girls, 90 boys) participants with and without DCD trait (age: 6-12 years), as assessed using the Japanese version of the Developmental Coordination Disorder Questionnaire (DCDQ-J), which consists of three subscales. Three-dimensional gait analysis data were obtained during the gait trials. GDI, step length, and step time data were recorded for both the right and left legs, and symmetry ratios were calculated.

RESULTS

Participants in the DCD trait group (n = 30) had a significantly lower GDI score (p < 0.0001) and a higher GDI symmetry ratio (p = 0.004) than typically developing children. Furthermore, DCD trait was related to the GDI symmetry ratio (odds ratio, 1.2; p = 0.001; 95 % confidence interval, 1.062-1.289). The control during movement, which was a DCDQ-J subscale, was negatively correlated with the GDI symmetry ratio (r=-0.257, p<0.001).

SIGNIFICANCE

This study's results lend support to the hypothesis that an increase in the GDI symmetry ratio is associated with the DCD trait. A quantitative assessment of gait performance is important to help identify gait asymmetry, including gait quality, in children with a DCD trait. Children with a DCD trait have a poor ability to control the interaction of lower leg movements, which may cause bilateral asymmetry in gait quality.

Reporting and tracking objective functional outcome measures: implementation of a summary report for gait and balance measures

The aim of this manuscript is to describe knowledge gaps in the literature, future directions, and emerging applications of gait and balance analysis in spine surgery with regard to functional outcomes measurement. Functional outcome measurement has been established as a useful clinical and research investigational tool in musculoskeletal disease. Evidence currently supports its use in the diagnosis, treatment, and outcome measurement of multiple musculoskeletal disease states, including spinal disease, and its usefulness continues to grow as literature develops. Gait and balance analysis has proven to be broadly applicable, but most clinicians remain unfamiliar and untrained in its usage. The logistical and communication barriers are also described with the potential solutions that are on the near horizon of research. This article describes our methodology for improving conveyance of functional outcome measures in spine surgery. Additionally, we provide a case example of an adult patient with spinal deformity who is examined pre and post operatively using our methodology.

The Effectiveness of Robot- vs. Virtual Reality-Based Gait Rehabilitation: A Propensity Score Matched Cohort

Robot assisted gait training (RAGT) and virtual reality plus treadmill training (VRTT) are two technologies that can support locomotion rehabilitation in children and adolescents affected by acquired brain injury (ABI). The literature provides evidence of their effectiveness in this population. However, a comparison between these methods is not available. This study aims at comparing the effectiveness of RAGT and VRTT for the gait rehabilitation of children and adolescents suffering from ABI. This is a prospective cohort study with propensity score matching. Between October 2016 and September 2018, all patients undergoing an intensive gait rehabilitation treatment based on RAGT or VRTT were prospectively observed. To minimize selection bias associated with the study design, patients who underwent RAGT or VRTT were retrospectively matched for age, gender, time elapsed from injury, level of impairment, and motor impairment using propensity score in a matching ratio of 1:1. Outcome measures were Gross Motor Function Mesure-88 (GMFM-88), six-min walking test (6MWT), Gillette Functional Assessment Questionnaire (FAQ), and three-dimensional gait analysis (GA). The FAQ and the GMFM-88 had a statistically significant increase in both groups while the 6MWT improved in the RAGT group only. GA highlighted changes at the proximal level in the RAGT group, and at the distal district in the VRTT group. Although preliminary, this work suggests that RAGT and VRTT protocols foster different motor improvements, thus recommending to couple the two therapies in the paediatric population with ABI.

Characteristics and patterns of pediatric chemotherapy-induced peripheral neuropathy: A systematic review

This systematic review provides a high-quality synthesis of the empirical evidence regarding chemotherapy-induced peripheral neuropathy (CIPN) characteristics and patterns described in studies of children who received neurotoxic chemotherapy to treat cancer. PubMed, CINAHL, PsycINFO, and Embase were searched for articles published 2009 - 2019, yielding 861. Forty-two papers met the eligibility criteria, including 31 that described characteristics and patterns of vincristine-induced CIPN. Fifty-seven percent of articles were of low to moderate quality; measurement flaws were the most common limitations. The reported CIPN incidence varies widely (2.8%-100%) depending on risk factors (e.g., race) and the measurement approach. Incidence rates of sensory, motor, autonomic CIPN, and pain were 12-28%, 50-72%, 0.8-83% and 5.7-44%, respectively. The evidence suggests that sensory and motor neuropathy, pain, and functional deficits are common and can persist into adulthood. Caucasian race is a risk factor and, contrary to prior thinking, cumulative chemotherapy dosage alone does not predict CIPN severity. The influence of other risk factors is less clear, and studies to date have not explored potential interactions among race, genetics, age, sex, drug metabolism, and nutritional status, among other factors.

Long-term functional outcomes after an external femoral derotation osteotomy in individuals with cerebral palsy

BACKGROUND

It is unknown how a femoral derotation osteotomy (FDO) during childhood affects functional outcomes in adulthood among individuals with bilateral cerebral palsy (CP).

RESEARCH QUESTIONS

How do long-term functional outcomes after an FDO compare to matched individuals who did not have an FDO? How do outcomes change over time?

METHODS

We queried the gait laboratory database for individuals who underwent an external FDO in childhood and were currently ≥25 years old. Participants returned for a long-term analysis (gait, physical examination, functional tests, imaging, questionnaires). The matched non-FDO group included only individuals in Gross Motor Function Classification System levels I-II, yielding three groups (non-FDO I-II, FDO I-II, FDO III-IV).

RESULTS

Sixty-one adults (11 non-FDO, 34 FDO I-II, 16 FDO III-IV) returned 13-25 years after baseline (non-FDO) or surgery (FDO). The non-FDO and FDO I-II groups were matched at baseline on most variables, except the FDO group had weaker hip abductors. At long-term, groups were similar on gait variables (median long-term hip rotation [primary outcome], non-FDO: -4°, FDO I-II: -4°, FDO III-IV: -5°), hip abduction test, fear of falling, and most pain measures despite anteversion being 29° greater in the non-FDO group. The FDO I-II group reported more falls than the non-FDO group. All groups improved on hip rotation, foot progression, and hip abductor strength. Speed and step length decreased/tended to decrease for all three groups. Hip abduction moment and gait deviation index did not change. Improvements in the FDO groups were maintained from short- to long-term.

SIGNIFICANCE

These results challenge the notion that an FDO is necessary to correct mean stance hip rotation for higher functioning individuals since nearly identical results were achieved by adulthood in the non-FDO I-II group. However, an FDO provides improvement earlier and maintenance from short- to long-term. This should factor into the shared decision-making process.

Relationship between the skeletal muscle mass index and physical activity of Japanese children: A cross-sectional, observational study

Regular physical activity is an important component of physical health of children and has been associated with increasing skeletal muscle mass and muscle strength. Children with low levels of physical activity may experience health problems, such as loss of muscle mass, later in life. Thus, it may be valuable to identify declining physical function in children who do not perform the recommended amount of physical activity. Therefore, we aimed to evaluate the relationship between the amount of physical activity performed for ≥60 min per day for ≥5 days per week and the skeletal muscle mass index and physical function in young children. In total, 340 typically developing children aged 6–12 years (175 girls; average age, 9.5±1.9 years) were included in this cross-sectional study. We evaluated the proportion of children performing the recommended minimum of 60 min of daily moderate-to-vigorous physical activity at least 5 days per week. The skeletal muscle mass and Gait Deviation Index scores, gait speed, grip strength, Five Times Sit-to-Stand test results, Timed Up-and-Go test results, one-leg standing time, and gait efficiency were evaluated. Multiple logistic regression analyses were performed to assess the association of moderate-to-vigorous physical activity with the skeletal muscle mass index, percent body fat, and physical function, after controlling for confounding factors (age and sex). A logistic regression analysis revealed that the skeletal muscle mass index was independently associated with moderate-to-vigorous physical activity (odds ratio, 2.34; 95% confidence interval, 1.17–4.71; P = 0.017). Performance of moderate-to-vigorous physical activity for ≥5 days per week for ≥60 min per day was associated with the skeletal muscle mass index score of Japanese children. Our findings highlighted the importance of performing moderate-to-vigorous physical activity for the development of skeletal muscle mass in children.

The influence of preoperative knee flexion contracture severity on short-term outcome of orthopedic surgery in ambulatory children with bilateral cerebral palsy

BACKGROUND

Indications and cutoff value of deformities to determine surgical procedures for flexed knee gait are not clear. The aim was to determine the influence of none or mild, and moderate preoperative knee flexion contracture on the improvement of gait after orthopedic surgery in children with bilateral cerebral palsy (CP).

METHODS

Inclusion criteria; bilateral CP, Gross Motor Function Classification System level I-III, and pre- and post operative-gait analysis. The 132 individuals identified were categorized into 2 groups based on the severity of knee flexion contracture (group 1: none or less than 11°; group 2: greater than or equal to 11°), and then matched according to the exact same soft tissue and/or bony orthopedic surgical procedures performed. The indication for surgery was to prevent progressive development of knee flexion contracture and stance phase flexed knee gait. Pre- and postoperative physical examination and gait analysis data were analyzed retrospectively.

RESULTS

Sixty (30 + 30) children, with mean age 10.6 years in each group, were included. The average follow-up time was 17 months. Gait Deviation Index (GDI) improved in group 1 from mean 66 (SD 19) to 74 (15), p = 0.004, and in group 2 from 60 (13) to 69 (15), p = 0.001. Knee flexion in stance improved in group 1 from 21.4 (16.1) to 12.1 (16.0) degrees, p = 0.002, and in group 2 from 32.2 (14.2) to 17.0 (15.9), p = 0.001. Step length improved in both groups, p = 0.017 and p = 0.008, respectively. Only in group 2 significant improvement was noted in walking speed, p = 0.018 and standing function, Gross Motor Function Measure (GMFM-D), p = 0.001. Knee flexion contracture decreased in group 1 from mean 4.6 (5.3) to 2.1 (8.3) degrees, p = 0.071 and in group 2 from 17.2 (4.9) to 9.6 (9.3), p = 0.001. There was no statistical difference between groups in pre-post improvement of GDI or other variables, except GMFM-D.

CONCLUSIONS

Relative mild to moderate preoperative knee flexion contracture does not influence the short-term improvement of gait after orthopedic surgery in children with bilateral CP.

Evaluating cost function criteria in predicting healthy gait

Accurate predictive simulations of human gait rely on optimisation criteria to solve the system's redundancy. Defining such criteria is challenging, as the objectives driving the optimization of human gait are unclear. This study evaluated how minimising various physiologically-based criteria (i.e., cost of transport, muscle activity, head stability, foot-ground impact, and knee ligament use) affects the predicted gait, and developed and evaluated a combined, weighted cost function tuned to predict healthy gait. A generic planar musculoskeletal model with 18 Hill-type muscles was actuated using a reflex-based, parameterized controller. First, the criteria were applied into the base simulation framework separately. The gait pattern predicted by minimising each criterion was compared to experimental data of healthy gait using coefficients of determination (R²) and root mean square errors (RMSE) averaged over all biomechanical variables. Second, the optimal weighted combined cost function was created through stepwise addition of the criteria. Third, performance of the resulting combined cost function was evaluated by comparing the predicted gait to a simulation that was optimised solely to track experimental data. Optimising for each of the criteria separately showed their individual contribution to distinct aspects of gait (overall R²: 0.37-0.56; RMSE: 3.47-4.63 SD). An optimally weighted combined cost function provided improved overall agreement with experimental data (overall R²: 0.72; RMSE: 2.10 SD), and its performance was close to what is maximally achievable for the underlying simulation framework. This study showed how various optimisation criteria contribute to synthesising gait and that careful weighting of them is essential in predicting healthy gait.

Motion analysis and surgical results of anterior transfer of flexor hallucis longus for equinovarus gait in children with hemiplegia

BACKGROUND

Rigid equinovarus foot deformities are seen in patients with cerebral palsy (CP). This retrospective study was undertaken to evaluate flexor hallucis longus tendon (FHL) transfer with gastrocsoleus recession (GSR) using motion analyses and quantitative measurement, and to investigate postoperative complications.

METHODS

This study included 10 hemiplegic CP patients who underwent FHL transfer with GSR, and were evaluated by motion analyses consisting of weight distribution in static standing position and three-dimensional gait analysis, both pre and post-operatively. They were assessed in terms of kinematic data, Gait Variable Scores (GVS), and Gait Profile Score (GPS).

RESULTS

The mean age at operation was 7.3 years (range, 4-13 years), and mean follow-up duration was 35 months (range, 25-64 months) post-operatively. Weight distribution at surgical site significantly rose from 34.3% pre-operatively to 47.3% post-operatively, and abnormal asymmetry of weight distribution between surgical site and contralateral site disappeared post-operatively. Maximum ankle dorsiflexion (ADF) at initial contact rose from -20.9° to -6.28°. Similarly, Maximum ADF at both stance and swing phase rose from -13.8° to 17.7° (P = 0.0003), and from -19.5° to 1.35° (P = 0.001), respectively. Although mean GPS decreased from 15.6° pre-operatively to 11.8°, which corresponded to 2.38 times the minimal clinically important difference (MCID = 1.6°), three cases manifested talipes calcaneus at final follow-up.

CONCLUSION

Although quantitative assessment showed that the potential value of FHL transfer with GSR was to obtain initial heel contact and maintain sufficient clearance from the ground in swing, it also revealed a risk of leading to talipes calcaneus. In the near future, we should establish accurate criteria for determination of transfer site, and consider the possibility of modification of this procedure in order to balance between recurrent equinus and significant talipes calcaneus.

STUDY DESIGN

Clinical comparison between preoperative and postoperative.

Lumbar Decompression and Interbody Fusion Improves Gait Performance, Pain, and Psychosocial Factors of Patients With Degenerative Lumbar Spondylolisthesis

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

Evaluate changes in gait, pain, and psychosocial factors among degenerative lumbar spondylolisthesis (DLS) patients before and 3 months after surgical intervention.

METHODS

Forty-four symptomatic DLS patients performed clinical gait analysis 1 week before surgery and 3 months after surgery. Patients performed a series of over-ground gait trials at a self-selected speed. Twenty-two matched asymptomatic controls underwent the same battery of tests. Three-dimensional motion tracking was used to analyze gait kinematics. Patient-reported outcomes, gait range of motion, and spatiotemporal parameters compared before and after lumbar decompression with fusion.

RESULTS

Surgical intervention resulted in significant improvements in walking speed (P = .021), stride time (P = .020), step time (P = .014), and single-support time (P = .038). Significant improvements in joint range-of-motion were found for knee (P = .002) and hip flexion (P = .006). Degenerative lumbar spondylolisthesis patients reported significant reductions in pain, disability, and improved psychological perceptions for fear-avoidance of pain and motion (all P < .001).

CONCLUSIONS

Surgical treatment of DLS resulted in a faster, more efficient gait in addition to significant reductions in pain, disability, and psychological fear associated with pain and motion. These beneficial changes that we identified early in the postoperative period indicate that patients return to the quality of life they seek early on. Clinical gait analysis provides objective, quantifiable measures of gait parameters that provide new insight into both the preoperative disability associated with DLS and into the early postoperative function of patients during their rehabilitation.

Factors related to better outcomes after single-event multilevel surgery (SEMLS) in patients with cerebral palsy

BACKGROUND

Good outcomes have been described after single-event multilevel surgery (SEMLS) in cerebral palsy (CP); however, there is limited evidence regarding factors influencing them.

RESEARCH QUESTION

What were the factors related to kinematic outcomes after SEMLS in the present study?

METHODS

Two hundred and fifty-eight patients with spastic diplegic CP, GMFCS I-III, who underwent SEMLS and had done pre and post-operative gait analyses were included in the SEMLS Group (SEMLS-G). A second search was performed in the same database looking for patients to compose the Control Group (CG), and 88 subjects, with at least two gait analyses and with no surgical intervention between tests, were identified. Demographic data, GDI and GPS (Gait Profile Score) were analyzed in both groups, and the results compared. A second evaluation was performed in the SEMLS-G in order to identify the influence of age, gender, follow-up time, pre-operative GDI, GMFCS and gait velocity on results.

RESULTS

The GDI (51.3-58.4) and GPS (2.5°) improvement occurred only in SEMLS-G (p < 0.001). On sagittal plane, there was an improvement at the knee and ankle levels in SEMLS-G, whereas the pelvic alignment improved in the CG. In SEMLS-G, patients with improvement on GDI > 10 points had lower pre-operative GDI (46.15) than other groups (p < 0.001). In addition, patients with reduction on GDI after intervention had lower pre-operative gait velocity than subjects with improvement >10 points (p = 0. 01). The increase on GDI after SEMLS was greater in patients GMFCS I and II than GMFCS III (p = 0.003). There was a negative effect of GMFCS III on GDI improvement after intervention (p = 0.014).

SIGNIFICANCE

Lower pre-operative GDI, higher baseline gait velocity and GMFCS levels I and II were related to better outcomes after SEMLS in the present study. On the other hand, patients GMFCS III were more susceptible to deteriorate after SEMLS.

Three dimensional gait analyses in dizygotic twin athletes

Gait analysis and gait indices are frequently used to evaluate gait pathologies and outcomes. The aim of this study is to investigate the differences in gait parameters of dizygotic twin athletes according to each other and athletes group who are similar age but non-twin. Eighty-four athletes without any disease that could cause gait pathology were included the study. Time-distance measurements, kinematic - kinetic variables, and gait deviation index (GDI) of the gait functions of twin athletes (17 boys and 25 girls, height: 153.9 ± 15 cm, weight: 45.9 ± 12 kg, leg length 80.5 ± 11 cm) were compared with each other and with 42 sex and age matched non-twins athletes (height: 155 ± 15 cm, weight: 47 ± 14 kg, leg length 80.6 ± 9.8 cm, mean age 11.8 ± 2.29, range 6-15 years). No statistically significant difference was found about the time, distance parameters and GDIs in comparison of twin athletes with each other and the non-twin group. Additionally, kinetic and kinematic variables were similar in between twins. We measured lower adduction angles and higher abduction angles in non-twin athletes in comparison to the twin athletes (p = 0.01, 0.04). Additionally, the angle of knee flexion at the first contact was higher in non-twins (p = 0.003).Being dizygotic twin seems to have no clinical effect on gait function in athletes.

Children with Cerebral Palsy Have Similar Walking and Running Quality Assessed by an Overall Kinematic Index

Running ability is critical to maintaining activity participation with peers. Children and adolescents with cerebral palsy (CP) are often stated to run better than they walk, but running is not often quantitatively measured. The purpose of this study was to utilize overall gait deviation indices to determine if children with diplegic CP run closer to typically developing children than they walk. This retrospective comparative study utilized 3D running kinematics that were collected after walking data at two clinical motion analysis centers for children with diplegic cerebral palsy. Separate walking and running Gait Deviation Indices (GDI Walk and GDI* Run), overall indices of multiple plane/joint motions, were calculated and scaled for each participant so that a typically developing mean was 100 with standard deviation of 10. An analysis of variance was used to compare the variables Activity (walking vs running) and Center (data collected at two different motion analysis laboratories). Fifty participants were included in the study. The main effect of Activity was not significant, mean GDI Walk = 76.4 while mean GDI* Run = 77.1, p = 0.84. Mean GDI scores for walking and running were equivalent, suggesting children with diplegic cerebral palsy as a group have similar walking and running quality. However, individual differences varied between activities, emphasizing the need for individual assessment considering specific goals related to running.

Geometrical restoration during total hip arthroplasty is related to change in gait pattern - a study based on computed tomography and three-dimensional gait analysis

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.

The Actuation System of the Ankle Exoskeleton T-FLEX: First Use Experimental Validation in People with Stroke

Robotic devices can provide physical assistance to people who have suffered neurological impairments such as stroke. Neurological disorders related to this condition induce abnormal gait patterns, which impede the independence to execute different Activities of Daily Living (ADLs). From the fundamental role of the ankle in walking, Powered Ankle-Foot Orthoses (PAFOs) have been developed to enhance the users’ gait patterns, and hence their quality of life. Ten patients who suffered a stroke used the actuation system of the T-FLEX exoskeleton triggered by an inertial sensor on the foot tip. The VICONmotion capture system recorded the users’ kinematics for unassisted and assisted gait modalities. Biomechanical analysis and usability assessment measured the performance of the system actuation for the participants in overground walking. The biomechanical assessment exhibited changes in the lower joints’ range of motion for 70% of the subjects. Moreover, the ankle kinematics showed a correlation with the variation of other movements analyzed. This variation had positive effects on 70% of the participants in at least one joint. The Gait Deviation Index (GDI) presented significant changes for 30% of the paretic limbs and 40% of the non-paretic, where the tendency was to decrease. The spatiotemporal parameters did not show significant variations between modalities, although users’ cadence had a decrease of 70% of the volunteers. Lastly, the satisfaction with the device was positive, the comfort being the most user-selected aspect. This article presents the assessment of the T-FLEX actuation system in people who suffered a stroke. Biomechanical results show improvement in the ankle kinematics and variations in the other joints. In general terms, GDI does not exhibit significant increases, and the Movement Analysis Profile (MAP) registers alterations for the assisted gait with the device. Future works should focus on assessing the full T-FLEX orthosis in a larger sample of patients, including a stage of training.

Influence of Etiology and Onset of Deformity on Spatiotemporal, Kinematic, Kinetic, and Electromyography Gait Variables in Patients with Scoliosis-A Prospective, Comparative Study

STUDY DESIGN

Prospective comparative study.

OBJECTIVE

The aim of this study was to compare the spatiotemporal, kinematic, kinetic and electromyographic (EMG) gait variables in patients with adolescent idiopathic scoliosis (AIS) and congenital scoliosis and to compare these gait variables of scoliosis patients with healthy controls.

SUMMARY OF BACKGROUND DATA

Earlier studies have solely focussed on the possibility of altered gait patterns in AIS patients; not much light has been shed on the differences in gait patterns in congenital and adolescent scoliosis patients.

METHODS

Forty scoliosis patients (20 each with AIS and congenital scoliosis) and 20 healthy volunteers were prospectively recruited. After thorough clinical and radiological examination, all patients underwent gait analysis in accordance with standard protocols.The outcome measures included spatiotemporal, kinetic, kinematic and EMG activity. Composite indices for gait analysis-Gait Profile Score (GPS) and Gait Deviation Index (GDI)-were also calculated. Relevant statistical tests were applied to compare the different groups.

RESULTS

No significant difference was found between the AIS and congenital scoliosis groups with respect to baseline demographic and radiological parameters. The two subgroups of scoliosis patients (AIS and congenital) did not differ significantly with respect to any of the measured gait analysis parameters. However, when compared to the healthy age-matched control group, the scoliosis patients differed significantly with respect to gait speed, stride length, step length, GDI, GPS and peak EMG activation for erector spinae, biceps femoris, semimembranosus, rectus femoris, gastrocnemious, and tibialis anterior.

CONCLUSION

Our findings confirm the previous findings of literature regarding the alteration in gait patterns in scoliosis patients when compared to normal individuals. However, the lack of difference in gait analysis variables between AIS and congenital scoliosis patients suggests that this alteration in gait is secondary to the existence of the deformity and does not correlate with the onset or etiology of deformity.Level of Evidence: 2.

Greater Reliance on Cerebral Palsy-Specific Muscle Synergies During Gait Relates to Poorer Temporal-Spatial Performance Measures

Children with cerebral palsy typically exhibit reduced complexity of muscle coordination patterns during walking; however, the specific patterns that characterize their gait abnormalities are still not well documented. This study aimed to identify the specific repertoire of muscle coordination patterns in children with CP during walking compared to same-aged peers without CP and their relationships to gait performance. To identify muscle coordination patterns, we extracted muscle synergies from 10 children with CP and 10 age-matched typically developing children (TD). K-mean clustering and discriminant analyses of all extracted synergies were used to group similar synergies. Then, weight-averaged z-scores were quantified for each cluster to determine their group-specific level. In this cohort, 10 of the 17 distinct clusters were largely CP-specific while six clusters were seen mainly in TD, and one was non-specific. CP-specific clusters generally showed merging of two TD synergies, excessive antagonist co-activation, decreased muscle activation compared to TD, and complex or atypical pattern. Significant correlations were found between weight-averaged z-scores and step length asymmetry, cadence asymmetry, self-selected treadmill speed and AP-COM displacement of the pelvis such that greater CP-specificity of muscle synergies was related to poorer performance, thus indicating that CP-specific synergies can influence motor dysfunction.

Osteoarthritis year in review 2020: mechanics

The mechanical environment of the joint during dynamic activity plays a significant role in osteoarthritis processes. Understanding how the magnitude, pattern and duration of joint-specific loading features contribute to osteoarthritis progression and response to treatment is a topic of on-going relevance. This narrative review synthesizes evidence from recent papers that have contributed to knowledge related to three identified emerging subthemes: 1) the role of the joint mechanical environment in osteoarthritis pathogenesis, 2) joint biomechanics as an outcome to arthroplasty treatment of osteoarthritis, and 3) methodological trends for advancing our knowledge of the role of biomechanics in osteoarthritis. Rather than provide an exhaustive review of a broad area of research, we have focused on evidence this year related to these subthemes. New research this year has indicated significant interest in using biomechanics investigations to understand structural vs clinical progression of osteoarthritis, the role and interaction in the three-dimensional loading environment of the joint, and the contribution of muscle activation and forces to osteoarthritis progression. There is ongoing interest in understanding how patient variability with respect to gait biomechanics influences arthroplasty surgery outcomes, and subgroup analyses have provided evidence for the potential utility in tailored treatment approaches. Finally, we are seeing a growing trend in the application of translational biomechanics tools such as wearable inertial measurement units for improved integration of biomechanics into clinical decision-making and outcomes assessment for osteoarthritis.

Preoperative and Postoperative, Three-dimensional Gait Analysis in Surgically Treated Patients With High-grade Spondylolisthesis

BACKGROUND

High-grade spondylolisthesis (HGS) (Myerding grade III-V) in adolescents can lead to a marked alteration of gait pattern and maybe the presenting symptom in these patients. This characteristic gait pattern in patients with HGS has been referred to as the "pelvic waddle." Modern 3-dimensional (3D) gait analysis serves an important tool to objectively analyze the different components of this characteristic gait preoperatively and postoperatively and is an objective measure of postoperative improvement.This study demonstrates the use of 3D gait analysis preoperatively and postoperatively in a cohort of 4 consecutive patients with HGS treated surgically at a single tertiary referral center and utilize this to objectively evaluate outcome of surgical treatment in these patients. This has not been reported previously in a cohort of patients.

METHODS

This is a prospective analysis of patients with HGS who underwent surgical intervention for spondylolisthesis at a single institution. Patient demographics, clinical, and radiologic assessment were recorded, and all patients underwent 3D gait analysis before and after surgical intervention. Kinetic, kinematic, and spatial parameters were recorded preoperatively and postoperatively for all patients. This allowed the outcome of change in gait deviation index, before and after surgical treatment, to be evaluated.

RESULTS

We were able to review complete records of 4 adolescent patients who underwent surgical treatment for HGS. Mean age at surgery was 13.5 years with a minimum follow-up of 2.5 years postoperatively (average 40 mo). Preoperative gait analysis revealed marked posterior pelvic tilt in 2 patients, reduced hip and knee extension in all 4 patients and external foot progression in 3 of the 4 patients. Along with an observed improvement in gait, there was an objective improvement in gait parameters postoperatively in all 4 patients. Gait deviation index score improved significantly from 78.9 to 101.3 (mean).

CONCLUSIONS

Preoperative gait abnormalities exist in HGS and can be objectively analyzed with gait analysis. Surgical intervention may successfully resolve these gait abnormalities and gait analysis is a useful tool to assess the outcome of surgery and quantify an otherwise intangible benefit of surgical intervention.

LEVEL OF EVIDENCE

Level IV-case series.

Three-Dimensional Gait Analysis in Children Undergoing Gastrocsoleus Lengthening for Equinus Secondary to Cerebral Palsy

Background and Objectives: Equinus is the most common deformity in children with cerebral palsy, and surgical lengthening of the gastrocsoleus muscle-tendon unit is the most commonly performed operation for children with cerebral palsy. Treatment outcomes of orthopaedic surgery can be measured objectively with three-dimensional gait analysis. This study examined the quality of evidence for gastrocsoleus lengthening surgery based on objective measures. Materials and Methods: A search was performed with Medline, Embase and PubMed from 1990 to 25 August 2020 using the keywords "cerebral palsy", "equinus", "surgery" and "gait analysis". Only studies of gastrocsoleus lengthening surgery using three-dimensional gait analysis were included, yielding 34 studies. Results: Fourteen studies reported swing phase kinematics and all studies reported a significant improvement. Rates of recurrent equinus and calcaneus were reported in 21 studies and varied widely based on follow-up period and surgical technique. Conclusions: Poor study quality and marked variability in study samples and interventions made comparison difficult. Future studies should consider prospective design, controls or comparison groups and more detailed breakdowns of outcomes by cerebral palsy subtype, sagittal gait pattern, and equinus type in order to allow more rigorous treatment recommendations to be made.

Risk of Falling in a Timed Up and Go Test Using an UWB Radar and an Instrumented Insole

Previously, studies reported that falls analysis is possible in the elderly, when using wearable sensors. However, these devices cannot be worn daily, as they need to be removed and recharged from time-to-time due to their energy consumption, data transfer, attachment to the body, etc. This study proposes to introduce a radar sensor, an unobtrusive technology, for risk of falling analysis and combine its performance with an instrumented insole. We evaluated our methods on datasets acquired during a Timed Up and Go (TUG) test where a stride length (SL) was computed by the insole using three approaches. Only the SL from the third approach was not statistically significant (p = 0.2083 > 0.05) compared to the one provided by the radar, revealing the importance of a sensor location on human body. While reducing the number of force sensors (FSR), the risk scores using an insole containing three FSRs and y-axis of acceleration were not significantly different (p > 0.05) compared to the combination of a single radar and two FSRs. We concluded that contactless TUG testing is feasible, and by supplementing the instrumented insole to the radar, more precise information could be available for the professionals to make accurate decision.

IMU-Based Gait Normalcy Index Calculation for Clinical Evaluation of Impaired Gait

Inertial measurement units (IMU) have been used for gait analysis in many clinical studies, as a more convenient, low cost and less restricted alternative to the laboratory-based motion capture systems or instrumented walkways. Spatial-temporal gait parameters such as gait cycle duration and stride length calculated from the IMUs were often used in these studies for evaluating the impaired gait. However, the spatial-temporal information provided by IMUs is limited, and sometime suffers incomplete and less effective evaluation. In this study, we develop a novel IMU-based method for clinical gait evaluation. Nine gait variables including three spatial-temporal parameters and six kinematic parameters are extracted from two shank-mounted IMUs for quantifying patient's gait deviations. Based on those parameters, an IMU-based gait normalcy index (INI) is derived to evaluate the overall gait performance. Eight inpatient subjects with gait impairments caused by n-hexane neuropathy and ten healthy subjects were recruited. The proposed gait variables and INI were examined on the inpatients at three to five time instants during the rehabilitation process until being discharged. A comparison with healthy subjects and statistical analysis for the changes of gait variables and INI demonstrated that the proposed new set of gait variables and INI can provide adequate and effective information for quantifying gait abnormalities, and help understanding the progress of gait and effectiveness of therapy during rehabilitation process.

Kinematic cluster analysis of the crouch gait pattern in children with spastic diplegic cerebral palsy using sparse K-means method

BACKGROUND

Crouch gait pattern is a common gait pattern in children with diplegic cerebral palsy with excessive knee flexion throughout stance phase. Few studies have grouped this pattern of gait and usually have examined only the features of gait in the sagittal plane and mostly lower extremities without considering pelvis and trunk behavior. Studies usually categorize the gait pattern according to important variables from the researcher's point of view. Sparse K-means is high dimensional clustering methods that perform clustering and variable selection simultaneously even with low sample size and large number of variables. Our aim was to define existing clusters of crouch gait pattern in children with spastic diplegic cerebral palsy.

METHODS

Cluster analysis was applied on the lower extremity, pelvis and trunk gait kinematics data of 64 limbs of children with crouch gait pattern and 64 limbs of typically developing children. Eighty-nine kinematic variables were used as input variables for clustering.

FINDINGS

Four clusters of crouch gait pattern were defined. Sparse K-means identified influential variables and identified the knee and hip flexion as a major factor in clustering. Kinematic of the trunk, pelvis and ankle was determined in each cluster. Trunk and pelvis kinematic features were strongly correlated with the knee and hip joint flexion severity.

INTERPRETATION

Obtained clusters were confirmed observationally. With increasing knee flexion, the kinematic of the trunk and pelvis were further away from the patterns of typically developing individuals. The clusters ranking appear to be reasonable based on the crouch severity.

Improvement in Gait Pattern and its Relationship With Preoperative Pelvic Compensation After Surgery in Patients With Sagittal Plane Deformity

STUDY DESIGN

Prospective observational study.

OBJECTIVE

The aim of this study was to investigate the improvement in gait parameters after surgery and whether corrective surgery for sagittal imbalance would be influenced by preoperative pelvic compensation.

SUMMARY OF BACKGROUND DATA

There have been no other studies investigating the influence of preoperative pelvic compensation on surgical outcomes.

METHODS

A total of 32 patients who were scheduled to undergo corrective surgery for sagittal plane deformity were included and were followed-up for 1 year after surgery. Radiological parameters were measured on biplanar full-body imaging. Before surgery and 6 months after surgery, three-dimensional motion analyses were performed to estimate center of gravity (CoG) deviation from the center of mass (CoM), mean trunk kyphosis (TK) angle, gait deviation index (GDI), and kinematic parameters. Before surgery, the patients were classified into CoG+ and CoG- groups. "+" and "-" representing increases and decreases in the distance of CoG from CoM of the pelvic segment from first to third trials, respectively. Oswestry Disability Index (ODI) and EuroQol-5D (EQ-5D) were measured for 1 year after surgery.

RESULTS

All radiological parameters improved significantly after surgery. For gait parameters, CoG from CoM, mean TK angle, and minimum angle of the hip and knee joints in the stance phase during walking were significantly decreased after surgery and GDI scores significantly improved after surgery. The mean changes of the CoG distance from the CoG and the mean TK from first to third trials of gait analysis significantly decreased postoperatively. There were no significant differences in ODI and EQ-5D scores over 1-year follow-up assessment between CoG+ and CoG- groups.

CONCLUSION

Preoperative abnormal stooping gait, and progressive worsening of sagittal imbalance in patients with sagittal plane deformity improved after corrective surgery. Patients with preoperative dynamic sagittal imbalance could have similar surgical results to those without it after corrective surgery.

LEVEL OF EVIDENCE

3.

Lower Limb Deformity and Gait Deviations Among Adolescents and Adults With X-Linked Hypophosphatemia

BACKGROUND

X-linked hypophosphatemia (XLH) is a rare genetic disorder characterized by lower limb deformity, gait and joint problems, and pain. Hence, quality of life is substantially impaired. This study aimed to assess lower limb deformity, specific radiographic changes, and gait deviations among adolescents and adults with XLH.

DESIGN

Data on laboratory examination and gait analysis results were analyzed retrospectively. Deformities, osteoarthritis, pseudofractures, and enthesopathies on lower limb radiographs were investigated. Gait analysis findings were compared between the XLH group and the control group comprising healthy adults.

PATIENTS AND CONTROLS

Radiographic outcomes were assessed retrospectively in 43 patients with XLH (28 female, 15 male). Gait analysis data was available in 29 patients with confirmed XLH and compared to a healthy reference cohort (n=76).

RESULTS

Patients with XLH had a lower gait quality compared to healthy controls (Gait deviation index GDI 65.9% +/- 16.2). About 48.3% of the study population presented with a greater lateral trunk lean, commonly referred to as waddling gait. A higher BMI and mechanical axis deviation of the lower limbs were associated with lower gait scores and greater lateral trunk lean. Patients with radiologic signs of enthesopathies had a lower GDI.

CONCLUSIONS

This study showed for the first time that lower limb deformity, BMI, and typical features of XLH such as enthesopathies negatively affected gait quality among adolescents and adults with XLH.

Rapid and robust patterns of spontaneous locomotor deficits in mouse models of Huntington's disease

Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by severe disruption of cognitive and motor functions, including changes in posture and gait. A number of HD mouse models have been engineered that display behavioral and neuropathological features of the disease, but gait alterations in these models are poorly characterized. Sensitive high-throughput tests of fine motor function and gait in mice might be informative in evaluating disease-modifying interventions. Here, we describe a hypothesis-free workflow that determines progressively changing locomotor patterns across 79 parameters in the R6/2 and Q175 mouse models of HD. R6/2 mice (120 CAG repeats) showed motor disturbances as early as at 4 weeks of age. Similar disturbances were observed in homozygous and heterozygous Q175 KI mice at 3 and 6 months of age, respectively. Interestingly, only the R6/2 mice developed forelimb ataxia. The principal components of the behavioral phenotypes produced two phenotypic scores of progressive postural instability based on kinematic parameters and trajectory waveform data, which were shared by both HD models. This approach adds to the available HD mouse model research toolbox and has a potential to facilitate the development of therapeutics for HD and other debilitating movement disorders with high unmet medical need.

Gait Indices for Characterization of Patients with Unilateral Cerebral Palsy

As cerebral palsy (CP) is a complex disorder, classification of gait pathologies is difficult. It is assumed that unclassified patients show less functional impairment and less gait deviation. The aim of this study was to assess the different subgroups and the unclassified patients with unilateral CP using different gait indices. The Gillette Gait Index (GGI), Gait Deviation Index (GDI), Gait Profile Score (GPS) and spatiotemporal parameters derived from instrumented 3D-Gait Analysis (IGA) were assessed. Subgroups were defined using morphological and functional classification systems. Regarding the different gait indices, a ranking of the different gait patterns is evident. Significant differences were found between GMFCS level I and II, Winters et al. (Winters, Gage, Hicks; WGH) type IV and type I and the WGH-unclassified. Concerning the spatiotemporal parameters significant differences were found between GMFCS level I and II concerning velocity. The unclassified patients showed mean values for the different gait indices that were comparable to those of established subgroups. Established gait patterns cause different degrees of gait deviation and functional impairment. The unclassified patients do not differ from established gait patterns but from the unimpaired gait. Further evaluation using 3D-IGA is necessary to identify the underlying gait pathologies of the unclassified patients.

Outcomes of isolated soft tissue surgery for in-toeing gait in patients with ambulatory cerebral palsy

BACKGROUND

Soft tissue surgery to address in-toeing gait in young cerebral palsy (CP) patients may be an alternative in some cases to femoral derotation osteotomy (FDO), which is the currently accepted treatment. The relative contribution of muscular contracture, spasticity and bone deformity is still controversial. In this study, we determined the outcomes of soft tissue surgery on hip internal rotation (HIR) when femoral anteversion was less than 45° and the soft tissues were identified as being the cause.

METHODS

This prospective study included select adolescent patients who were operated in the context of single-event multilevel surgery. The soft tissues' contribution to the HIR was identified beforehand. The surgical procedures focused on the hamstrings, adductor magnus and gluteus minimus muscles.

RESULTS

Over a 6-year period, 21 patients (mean age 14 years) and 25 lower limbs were treated. The HIR improved by an average of 17.4°±4.8° (95% CI). The gait deviation index and gait profile score also improved significantly. At a mean follow-up of 36 months, no loss of correction had occurred.

DISCUSSION

In-toeing gait in CP patents is due to the action of retracted and/or spastic muscles and the presence of excessive bone torsion. When femoral anteversion<45°, confirming soft tissue involvement allows us to do a surgical procedure on the soft tissues only to correct the dynamic aspect of HIR. Our findings suggest that, under the right conditions, soft tissue surgery can improve in-toeing gain in the long term. This technique has its place alongside FDO in certain CP patients who do not have severe femoral anteversion.

Inter-rater reliability of a newly developed gait analysis and motion score

Background:

Gait analysis constitutes an essential part of orthopedic rehabilitation assessment. Previous studies indicate that observational-based gait analysis lacks reliability and requires extensive clinical training. Therefore, gait analysis in the clinical practice heavily relies on technical aids. The aim of the present study is to develop a reliable gait analysis assessment tool that can accurately assess clinically relevant gait cycle parameters in daily clinical practice.

Methods:

In this pilot study, a new gait analysis and motion score (GAMS), comprising 10 observational and 5 technically measured (e.g. pressure plate) gait parameters, was developed. The parameters were dichotomously operationalized, reflecting pathological versus physiological manifestations of the parameters. The rating algorithm was administered by 12 raters using videotaped treadmill sessions of 10 orthopedic subjects ( n = 120 ratings). Inter-rater reliability was calculated using the intraclass correlation coefficient (ICC) and the percentage of rating agreement.

Results:

The mean (standard deviation (SD)) GAMS ratings ranged from 10.0 (1.1) to 21.5 (1.3) points. The overall GAMS ICC was 0.98 (95% confidence interval (CI) 0.96–1.00), whereas the ICC of observational parameters alone was 0.97 (95% CI 0.93–0.99). The mean (SD) percentage of rating agreement was 86.1% (3.3%). For the observational parameters, the mean (SD) rating agreement was 82.5% (4.5%).

Conclusion:

This new GAMS shows excellent overall inter-rater reliability for a continuum of functional gait statuses. The new score may be an appropriate clinical tool to objectively evaluate patients’ gait patterns. Furthermore, the GAMS may find application as a clinician-reported outcome measure in orthopedic rehabilitation. Further studies are required to verify the validity and accuracy of the new GAMS and its functionality in assessing clinical changes in gait patterns.

Effectiveness of virtual reality-based gait education in enhancing the rehabilitation outcomes of injured military personnel

INTRODUCTION

Correcting adverse biomechanics is key in rehabilitating musculoskeletal injuries. Verbal instruction remains the primary method for correcting biomechanics and therefore a patient's understanding of these instructions is believed to directly influence treatment outcomes. The aim of this study was to establish the patients' perceptions of virtual reality-based gait education (VR-GEd) and to assess its influence on the standard military rehabilitation outcomes.

METHODS

A retrospective analysis using routinely collected data was performed. Twenty patients with lower-limb musculoskeletal injuries undertook a VR-GEd session on the commencement of a 3-week, multidisciplinary, inpatient course of rehabilitation. Patient outcomes were compared with a group of matched controls, completing the same standardised course of inpatient treatment.

RESULTS

The VR-GEd group exhibited greater reductions the interference pain had on their mood (p=0.022). Improvements in generalised anxiety (p=0.029) were greater in the VR-GEd group but were not large enough to be clinically meaningful. VR-GEd did not influence functional outcomes. Patients rated the sessions highly in terms of enjoyment and perceived value. Patient feedback highlighted that they understood their injury better and felt the session could positively influence their recovery.

CONCLUSION

VR-GEd was proven to be an enjoyable and valued means of educating military inpatients about their injury mechanics. This study found no contraindications for the inclusion of VR-GEd in current rehabilitation programmes. However, current evidence suggests a single VR-GEd session cannot act as a replacement for biofeedback interventions, due to the lack of enhanced improvement across rehabilitation outcomes.

Gait characteristics of children with Williams syndrome with impaired visuospatial recognition: a three-dimensional gait analysis study

Williams syndrome (WS) is a genetically based neurodevelopmental disorder characterized by intellectual disability and impaired visuospatial recognition. The aim of this study was to analyze the gait characteristics of WS children with impaired visuospatial recognition using a three-dimensional gait analysis (3DGA) to clarify the gait adaptation needed to compensate for it. 3DGA was performed in 8 WS children with impaired visuospatial recognition (mean age, 11.8 years) and 9 age-, sex-, height-, and weight-matched controls. Clinical data, fundamental motor tests, and gait variables while walking on a flat surface and walking up a mat were compared between the two groups, and the correlations between variables were analyzed in the WS children. WS children showed impairment of balance function without muscle weakness. In walking on a flat surface, the WS group showed reduced walking speed, short step length, increased variability of step length, increased knee flexion throughout the stance phase, increased horizontal pelvic range of motion (ROM), and a low Gait Deviation Index and a high Gait Profile Score, which are indices of gait quality. In walking up a mat, the WS group showed further reduced walking speed and decreased sagittal hip flexion and ankle dorsiflexion ROM in the swing phase. Impaired balance function was significantly correlated with increased variability of step length and decreased sagittal ankle dorsiflexion ROM in the swing phase. The detailed gait pattern of WS children with impaired visuospatial recognition was presented. These findings show that impaired visuospatial recognition and balance function contribute to gait adaptation.

Using directional statistics to test hypotheses regarding rigid body attitude: Comparison to univariate and multivariate Cardan angle tests

Rigid body attitude and single-joint kinematics are typically expressed using three Cardan angles which represent rotations in anatomical planes. It was recently shown in the Biomechanics literature that Cardan angles inaccurately estimate true mean attitude due to an important mathematical inadequacy: attitude under-representation; at least four quantities are needed to unambiguously specify attitude. Directional statistics, which is the multivariate generalization of (univariate) circular statistics, solves this problem using four-dimensional unit vectors and the mathematics of hyperspherical geometry. The purpose of this study was to compare the results of directional analysis to the results of uni- and multi-variate Cardan analysis for representative joint kinematic data during gait. We analyzed hip, knee and pelvis data from three open datasets and report exemplary results for knee kinematics in v-cut vs. side shuffle tasks. We also conducted Monte Carlo simulations, using synthetic data with precisely controlled true angular effects, to systematically compare directional and Cardan analyses. Results show that directional analysis yielded considerably smaller p values (p<0.03) than Cardan analysis (p>0.055) for the exemplary dataset. Simulation results confirmed that directional analysis is considerably more powerful (i.e., much more able to detect true angular effects) than both uni- and multi-variate Cardan analysis. These results suggest that directional statistics should be used to analyse attitude, including 3D joint kinematics, to avoid false negatives.

Comparison of the Results of Primary Versus Repeat Hamstring Surgical Lengthening in Cerebral Palsy

BACKGROUND

Hamstring surgical lengthening (HSL) has been frequently performed for the correction of knee flexion deformity in cerebral palsy (CP), although recurrence is described in long-term follow-up. Repeat hamstring surgical lengthening (RHSL) can be an option for recurrent knee flexion deformity; however, the results of this approach are still controversial. The purpose of this study was to compare the results of primary HSL and RHSL in CP.

METHODS

Patients with spastic diplegic CP, Gross Motor Function Classification System levels I to III, underwent bilateral medial HSL with complete documentation in the gait laboratory before and after the intervention, were included in the study. A total of 229 subjects met the inclusion criteria and were divided into 2 groups: group A was formed by those who received medial HSL for the first time (185 patients), and group B was composed of individuals who underwent RHSL (44 patients). Clinical and kinematic parameters were evaluated before and after the intervention, and the results compared.

RESULTS

The groups were matched with regard to sex distribution, Gross Motor Function Classification System levels, and follow-up time (>2 y). Popliteal angle was reduced in groups A (60.3 to 51.4 degrees, P<0.001) and B (56.1 to 51.5 degrees, P=0.001) after the intervention. Knee flexion at initial contact was reduced from 40.8 to 28.9 degrees in group A (P<0.001) and from 40.4 to 35.1 degrees in group B (P=0.001). Reduction of minimum knee flexion in the stance phase (24.9 to 17.5 degrees, P<0.001) and improvement of the Gait Deviation Index (52.9 to 60.2, P<0.001) occurred only in group A. Anterior pelvic tilt (APT) increased in groups A (from 17 to 19.5 degrees, P<0.001) and B (from 14.9 to 19.4 degrees, P<0.001) after treatment. Finally, in the comparison between groups, the reduction of knee flexion at initial contact was more significant in group A (P<0.001), whereas the increase of APT was higher in group B.

CONCLUSIONS

In the present study, the improvement of knee extension during the stance phase was observed only after the primary medial HSL. Moreover, the increase of APT was more significant when RHSL was performed.

LEVEL OF EVIDENCE

Level III.

3D gait analysis, haemophilia joint health score, leg muscle laterality and biomarkers of joint damage: A cross-sectional comparative assessment of haemophilic arthropathy

Introduction

3D gait analysis has been proposed as a reproducible and valid method to assess abnormal gait patterns and to monitor disease progression in patients with haemophilia (PWH).

Aim

This study aimed at comparing Gait Deviation Index (GDI) between adult PWH and healthy controls, and at assessing the agreement between outcome measures of haemophilic arthropathy.

Methods

Male PWH aged 18‐49 years (prespecified subgroups: 18‐25 vs 26‐49 years) on prophylactic replacement therapy, and male healthy age‐matched controls passed through a cross‐sectional assessment panel. Besides the 3D gait analysis derived GDI, secondary outcomes included kinematic, kinetic and spatio‐temporal gait parameters, the Haemophilia Joint Health Score (HJHS), electric impedance derived leg muscle laterality and inflammatory biomarkers.

Results

Patients with haemophilia (n = 18) walked slower, in shorter steps and accordingly with less functional range of motion in the hips and ankles, as compared to healthy controls (n = 24). Overall, PWH did not differ significantly in GDI and specific gait parameters. PWH had a higher mean HJHS (18.8 vs 2.6, P = .000) and leg muscle laterality (4.3% vs 1.5%, P = .004). A subgroup analysis revealed progressed gait pathology in PWH aged 26‐49 years (not statistically significant). Leg muscle laterality was strongly correlated with HJHS (r = .76, P = .000), whereas GDI just moderately (r = −.39, P = .110). PWH had higher levels of the inflammatory markers CRP and IL‐6.

Conclusion

Progressed gait pathology was found in PWH, mainly those aged 26‐49 years. Leg muscle laterality correlated strongly with HJHS and was identified as a promising tool for detecting progression and physiological consequences of haemophilic joint arthropathy.

Screw Anterior Distal Femoral Hemiepiphysiodesis in Children With Cerebral Palsy and Knee Flexion Contractures: A Retrospective Case-control Study

BACKGROUND

In children with cerebral palsy who demonstrate hamstring tightness, increasing attention is being paid to less invasive methods of correcting knee flexion contractures. Guided growth principles represent one such approach, and in tandem with a serial extension casting protocol, may provide a less invasive method of addressing these contractures. To date, no evidence is available on this combination of procedures. The purpose of this study was to investigate the effectiveness of a combined lengthening/guided growth procedure (hamstring lengthening, percutaneous anterior screw hemiepiphysiodesis, and serial extension casting) in addressing knee flexion contracture, and to compare this approach to hamstring lengthening and serial extension casting alone.

METHODS

Measures from preoperative and postoperative gait analyses were reviewed retrospectively for 10 patients with cerebral palsy who underwent anterior screw hemiepiphysiodesis and hamstring lengthening followed by serial extension casting [anterior epiphysiodesis (AE) group]. These findings were compared with measures from 19 patients with cerebral palsy who underwent hamstring lengthening followed by serial extension casting [no anterior epiphysiodesis (NAE) group]. Postoperative changes in clinical, functional, and kinematic parameters were assessed. Radiographic parameters were also assessed for the AE group.

RESULTS

In the AE group, improvements were measured in knee contracture, popliteal angle, peak stance phase knee extension, knee range of motion, and Gait Deviation Index. Similar results were observed in the NAE group. In the AE group, the lateral distal femoral angle increased into extension by 20.9 degrees at an average of 26-month follow-up. Both groups showed an increase in pelvic tilt postoperatively. There were no surgical complications associated with the screw anterior hemiepiphysiodesis. Four patients did have complaints of knee pain, but the pain was attributable to the implants in only one patient.

DISCUSSION

The AE group demonstrated statistically greater postoperative improvement in popliteal angle, knee flexion contracture, and peak knee extension during stance than the NAE group. Both procedures led to improvements in clinical and functional measures, indicating the validity of this approach as a means of correcting flexion contracture that is less invasive and allows immediate weight bearing.

LEVEL OF EVIDENCE

Level III-therapeutic study.

Anterior distal femoral hemiepiphysiodesis with and without patellar tendon shortening for fixed knee flexion contractures in children with cerebral palsy

PURPOSE

Surgery is often required for fixed knee flexion contractures in patients with neuromuscular conditions. Anterior distal femoral hemiepiphysiodesis (ADFH) is an alternative to distal femoral extension osteotomy (DFEO) in skeletally immature patients. ADFH is typically not accompanied by patellar tendon shortening surgery (PTS). Our purpose was to compare ADFH alone versus ADFH with PTS for treatment of fixed knee flexion contractures and crouched gait in children with cerebral palsy (CP).

METHODS

Retrospective review of pre- and postoperative gait analysis data for children with CP who underwent ADFH alone, or ADFH with PTS. Data were analysed using linear mixed models to control for covariates.

RESULTS

In total, 25 participants (42 limbs) were included, 17 male and eight female, mean age at surgery 12.9 (sd 1.9) years. Both groups experienced significant improvement in popliteal angle, knee extension range of motion (ROM) and knee extension in stance phase. Greater improvement was seen for all variables in the ADFH/PTS group, mainly due to greater popliteal angle and knee flexion during gait preoperatively in that group (p ≤ 0.02) rather than the procedure performed (p ≥ 0.19). There was no difference between groups postoperatively. Rate of contracture resolution was 0.5° to 1.0° per month, faster in larger contractures (p = 0.02).

CONCLUSIONS

ADFH with and without PTS is effective in improving knee extension in skeletally immature patients with CP, correcting contractures at a rate of 0.5° to 1.0° per month. Combined ADFH and PTS surgery may be preferable in patients with larger contractures of up to 30° to 35°.

LEVEL OF EVIDENCE

III.

Indications for gastrocsoleus lengthening in ambulatory children with cerebral palsy: a Delphi consensus study

PURPOSE

Equinus is the most common deformity in cerebral palsy (CP) and gastrocsoleus lengthening (GSL) is the most commonly performed surgery to improve gait and function in ambulatory children with CP. Substantial variation exists in the indications for GSL and surgical technique. The purpose of this study was to review surgical anatomy and biomechanics of the gastrocsoleus and to utilize expert orthopaedic opinion through a Delphi technique to establish consensus for surgical indications for GSL in ambulatory children with CP.

METHODS

A 17-member panel, of Fellowship-trained paediatric orthopaedic surgeons, each with at least 9 years of clinical post-training experience in the surgical management of children with CP, was established. Consensus for the surgical indications for GSL was achieved through a standardized, iterative Delphi process.

RESULTS

Consensus was reached to support conservative Zone 1 surgery in diplegia and Zone 3 surgery (lengthening of the Achilles tendon) was contraindicated. Zone 2 or Zone 3 surgery reached general agreement as a choice in hemiplegia and under-correction was preferred to any degree of overcorrection. Agreement was reached that the optimum age for GSL surgery was 6 years to 10 years and should be avoided in children aged under 4 years. Physical examination measures with the child awake and under anaesthesia were important in decision making. Gait analysis was supported both for decision making and for assessing outcomes, in combination with patient reported outcomes (PROMS).

CONCLUSIONS

The results from this study may encourage informed practice evaluation, reduce practice variability, improve clinical outcomes and point to questions for further research.

LEVEL OF EVIDENCE

V.

The Utility of Gait Deviation Index (GDI) and Gait Variability Index (GVI) in Detecting Gait Changes in Spastic Hemiplegic Cerebral Palsy Children Using Ankle-Foot Orthoses (AFO)

Background: Cerebral palsy (CP) children present complex and heterogeneous motor disorders that cause gait deviations. Clinical gait analysis (CGA) is used to identify, understand and support the management of gait deviations in CP. Children with CP often use ankle–foot orthosis (AFO) to facilitate and optimize their walking ability. The aim of this study was to assess whether the gait deviation index (GDI) and the gait variability index (GVI) results can reflect the changes of spatio-temporal and kinematic gait parameters in spastic hemiplegic CP children wearing AFO. Method: The study group consisted of 37 CP children with hemiparesis. All had undergone a comprehensive, instrumented gait analysis while walking, both barefoot and with their AFO, during the same CGA session. Kinematic and spatio-temporal data were collected and GVI and GDI gait indexes were calculated. Results: Significant differences were found between the barefoot condition and the AFO conditions for selected spatio-temporal and kinematic gait parameters. Changes in GVI and GDI were also statistically significant. Conclusions: The use of AFO in hemiplegic CP children caused a statistically significant improvement in spatio-temporal and kinematic gait parameters. It was found that these changes were also reflected by GVI and GDI. These findings might suggest that gait indices, such as GDI and GVI, as clinical outcome measures, may reflect the effects of specific therapeutic interventions in CP children.

Dimensional reduction of balance parameters in risk of falling evaluation using a minimal number of force-sensitive resistors

Purpose. As the instrumented insole is available for a wide commercial range in the retail trade, this study aims to reduce its overall cost using fewer sensors by carrying out an effective risk of falling evaluation. Methods. We compared the effect of reducing balance parameters using four and three force-sensing resistors (FSRs) of an instrumented insole. Data were previously collected among elderly participants during a Timed Up and Go (TUG) test. Results. While reducing the number of balance parameters, during sit-to-stand and stand-to-sit activities, the risk scores using four FSRs were not significantly different compared with three FSRs. Parameter reduction did not show any significant loss of information among the study population using four FSRs. For certain configurations of three FSRs, a significant effect of information loss was found in the study participants, revealing the importance of investigating the sensor locations in the process. Conclusions. We conclude that it is feasible to estimate a risk index during a TUG test not only after reducing the number of needed sensing units from four to three FSRs but also after reducing the number of balance parameters. The three FSRs should be located at strategic positions to avoid a significant loss of information.

Clinical gait analysis and physical examination don't correlate with physical activity of children with cerebral palsy. Cross-sectional study

Gait analysis and physical clinical measures are usually performed in children with cerebral palsy to help the surgeons make therapeutic decision. However, the level of physical activity in daily life is not systematically assessed. The aim of this cross sectional study was to examine the correlations between: three-dimensional gait analysis kinematic and spatiotemporal parameters, clinical measures and physical activity. Participants were 30 children with cerebral palsy (10–18 y), with GMFCS I–III. Daily physical activity was measured with an Actigraph GT3X accelerometer in free living environment during seven consecutive days. The percent of time spent in sedentary, in moderate to vigorous physical activity and the number of steps per day were computed from the accelerometer data. Kinematics parameters did not correlate with physical activity. Moderate correlations were found between spatio-temporal parameters and physical activity, for instance timing of toe-off (r = −0.40, p = 0.03). Few physical examination parameters were correlated with physical activity, such as the hip flexors selective motor control (r = 0.69 with moderate to vigorous activity and r = 0.70 with steps per day, p < 0.05). The physical activity profile cannot be sufficiently determined by a combination of clinical measures.

Quantification of abnormal upper limb movement during walking in people with acquired brain injury

BACKGROUND

Abnormal upper limb movements frequently affect people with acquired brain injury (ABI) during walking. Three-dimensional motion analysis (3DMA) can quantify upper limb abnormality kinematically, with composite scores condensing multiple joint axes data into a single score.

RESEARCH QUESTION

Are 3DMA-derived composite scores valid (known-groups and convergent validity), reliable and able to quantify speed-related changes in abnormal upper limb movement during walking?

METHODS

This observational study compared 42 adults with ABI and abnormal upper limb movements during walking with 36 healthy controls (HC) at a matched walking speed intention. Participants underwent 3DMA assessment of self-selected and fast walking speeds. Composite scores quantified the affected upper limb's kinematic abnormality. The Arm Posture Score arithmetic mean version (APSam) and 1.96 standard deviation reference-range scaled versions; the Kinematic Deviation Score mean (KDSm) and worst score (KDSw) were evaluated for association with each other and subjective abnormality rating (Pearson's 'r' correlation), test-retest reliability (intra-class correlation coefficient (ICC)), and ability to quantify speed-related changes in abnormal upper limb movement (Cohen's d effect size (ES), % change scores).

RESULTS

Very strong correlations existed between composite scores. The KDSm under-classified upper limb abnormality, whereas the KDSw captured the majority of ABI participants. All scores had moderate-strong correlations with subjective rating of abnormal upper limb movements (r = 0.54 - 0.79) and very strong test-retest reliability (ICCs > 0.81). The APSam demonstrated a 16% (ES = 0.76) walking speed-related increase in upper limb abnormality, whilst decreases were demonstrated in the KDSm 26% (ES 0.90) and KDSw 35% (ES 0.96).

SIGNIFICANCE

The APSam, KDSw, and number of abnormal joint axes comprehensively assess the whole upper limb abnormal movements, accurately classifies abnormality, and quantifies severity. This study illustrated notable presence of abnormal upper limb movements at self-selected walking speed and small increase at fast speeds. However, when scaled to HC variability, the fast walk kinematics became less abnormal due to increased HC movement variability.

Disease-specific gait deviations in pediatric patients with X-linked hypophosphatemia

BACKGROUND

X-linked hypophosphatemia (XLH) represents the most common genetic form of rickets featuring profound hypophosphatemia with associated skeletal and non-skeletal manifestations. Early onset gait disturbances contribute strongly to the burden of disease. However, no study has comprehensively characterized naturally occurring gait deviations in pediatric patients with XLH.

RESEARCH QUESTIONS

Can disease-specific gait deviations and potentially influencing factors be identified by gait analysis in non-surgically treated children with XLH?

METHODS

Gait laboratory assessments of 12 pediatric patients with XLH without previous long bone surgery was retrospectively analyzed and compared to age-matched healthy controls. Radiologic and clinical parameters of XLH patients were correlated with kinematic gait variables and gait scores.

RESULTS

Reduced external knee rotation and increased external hip orientation was ubiquitous in children with XLH. Increased lateral trunk lean, or "waddling gait", occurred in five children and was associated with varus knee deformities. Overall, children with XLH showed a reduced Gait Deviation Index (GDI) compared to controls. Radiologic and gait analysis revealed complex combined frontal and torsional deformity of the lower limbs as a common feature in XLH. Higher Body Mass Index (BMI) was associated with both lateral trunk lean and impaired GDI.

SIGNIFICANCE

Gait analysis is feasible to quantify gait deviations and lower limb deformities in pediatric patients with XLH. Specific gait characteristics including internal knee rotation and external hip rotation are common among patients with XLH and contribute to impaired gait scores. Our data suggest the use of gait and deformity data assessment as outcome parameters in future observational and interventional studies. Standardized assessment might contribute to targeted treatments to improve life quality in XLH patients.

SWEAT2 Study: Effectiveness of Trunk Training on Gait and Trunk Kinematics After Stroke: A Randomized Controlled Trial

OBJECTIVE

Trunk training after stroke is an effective method for improving mobility, yet underlying associations leading to the observed mobility carryover effects are unknown. The purposes of this study were to investigate the effectiveness of trunk training for gait and trunk kinematics and to find explanatory variables for the mobility carryover effects.

METHODS

This study was an assessor-masked, randomized controlled trial. Participants received either additional trunk training (n = 19) or cognitive training (n = 20) after subacute stroke. Outcome measures were the Tinetti Performance-Oriented Mobility Assessment (POMA), the Trunk Impairment Scale, spatiotemporal gait parameters, center-of-mass excursions, and trunk and lower limb kinematics during walking. Multivariate analysis with post hoc analysis was performed to observe treatment effects. Correlation and an exploratory regression analysis were used to examine associations with the mobility carryover effects.

RESULTS

Significant improvements after trunk training, compared with the findings for the control group, were found for the Trunk Impairment Scale, Tinetti POMA, walking speed, step length, step width, horizontal/vertical center-of-mass excursions, and trunk kinematics. No significant differences were observed in lower limb kinematics. Anteroposterior excursions of the trunk were associated with 30% of the variability in the mobility carryover effects.

CONCLUSIONS

Carryover effects of trunk control were present during ambulation. Decreased anteroposterior movements of the thorax were the main variable explaining higher scores on the Tinetti POMA Gait subscale. However, the implementation and generalizability of this treatment approach in a clinical setting are laborious and limited, necessitating further research.

IMPACT

Trunk training is an effective strategy for improving mobility after stroke. Regaining trunk control should be considered an important treatment goal early after stroke to adequately prepare patients for walking.

Deep neural networks enable quantitative movement analysis using single-camera videos

Many neurological and musculoskeletal diseases impair movement, which limits people's function and social participation. Quantitative assessment of motion is critical to medical decision-making but is currently possible only with expensive motion capture systems and highly trained personnel. Here, we present a method for predicting clinically relevant motion parameters from an ordinary video of a patient. Our machine learning models predict parameters include walking speed (r = 0.73), cadence (r = 0.79), knee flexion angle at maximum extension (r = 0.83), and Gait Deviation Index (GDI), a comprehensive metric of gait impairment (r = 0.75). These correlation values approach the theoretical limits for accuracy imposed by natural variability in these metrics within our patient population. Our methods for quantifying gait pathology with commodity cameras increase access to quantitative motion analysis in clinics and at home and enable researchers to conduct large-scale studies of neurological and musculoskeletal disorders.