Vision-based motion capture for the gait analysis of neurodegenerative diseases: A review.

BACKGROUND: Developments in vision-based systems and human pose estimation algorithms have the potential to detect, monitor and intervene early on neurodegenerative diseases through gait analysis. However, the gap between the technology available and actual clinical practice is evident as most clinicians still rely on subjective observational gait analysis or objective marker-based analysis that is time-consuming. RESEARCH QUESTION: This paper aims to examine the main developments of vision-based motion capture and how such advances may be integrated into clinical practice. METHODS: The literature review was conducted in six online databases using Boolean search terms. A commercial system search was also included. A predetermined methodological criterion was then used to assess the quality of the selected articles. RESULTS: A total of seventeen studies were evaluated, with thirteen studies focusing on gait classification systems and four studies on gait measurement systems. Of the gait classification systems, nine studies utilized artificial intelligence-assisted techniques, while four studies employed statistical techniques. The results revealed high correlations of gait features identified by classifier models with existing clinical rating scales. These systems demonstrated generally high classification accuracies and were effective in diagnosing disease severity levels. Gait measurement systems that extract spatiotemporal and kinematic joint information from video data generally found accurate measurements of gait parameters with low mean absolute errors, high intra- and inter-rater reliability. SIGNIFICANCE: Low cost, portable vision-based systems can provide proof of concept for the quantification of gait, expansion of gait assessment tools, remote gait analysis of neurodegenerative diseases and a point of care system for orthotic evaluation. However, certain challenges, including small sample sizes, occlusion risks, and selection bias in training models, need to be addressed. Nevertheless, these systems can serve as complementary tools, equipping clinicians with essential gait information to objectively assess disease severity and tailor personalized treatment for enhanced patient care.

A Comparison of Objectively Measured Free-Living Physical Behaviour in Adults with and without Lower Limb Amputation.

Objectively monitored free-living physical behaviours of adults with and without lower limb amputation (LLA) were compared. METHODS: 57 adults with LLA wore an activPAL3™ for 8 days. A comparison data set (n = 57) matched on gender, age and employment status was used. Variables included: time sitting; standing; stepping; sit-to-stand transitions; step count and cadence. Comparisons were made between adults with and without LLA and between gender, level and cause of amputation. RESULTS: Participants with LLA due to trauma versus circulatory causes were less sedentary and more active; however, no difference in physical behaviour was recorded across gender or level of amputation. Participants with LLA spent more time sitting (p < 0.001), less time standing and stepping (p < 0.001) and had a lower step count (p < 0.001). Participants with LLA took more steps in cadence bands less than 100 steps·min-1 and fewer steps in cadence bands greater than 100 steps·min-1 compared to participants without LLA. CONCLUSIONS: People with LLA were less active and more sedentary than people without LLA and participated in less activity at a moderate or higher intensity when matched on age, gender and employment. Interventions are needed to promote active lifestyles in this population.

Physical activity guidelines and promotion: An online survey of United Kingdom's prosthetic rehabilitation healthcare professionals.

BACKGROUND: Healthcare professionals play a key role in supporting physical activity participation for people with lower limb absence. OBJECTIVES: The objectives of this study were to survey healthcare professionals' views of people with lower limb absence in the United Kingdom, explore their awareness and knowledge of physical activity recommendations and investigate their current and desirable practice towards physical activity promotion. STUDY DESIGN: Cross-sectional study. METHODS: Potential participants were identified from open-access health-related databases, educational institution databases, and the authors' professional networks. An online 40-item questionnaire was distributed electronically and by post. Survey items were multiple choice, Likert-type scale or open-ended questions to explore the characteristics of healthcare professionals, awareness/knowledge of physical activity guidelines, current and desired practice and views on physical activity promotion. RESULTS: In total, 106 people responded. Physiotherapists had greater awareness/knowledge of physical activity guidelines compared to prosthetists/orthotists and other respondents. Awareness/knowledge of guidelines decreased as age, experience and time since qualification increased. The most common source of knowledge was self-directed learning. CONCLUSION: Continuing and improving education on the content of physical activity guidelines may be helpful for healthcare professionals in promoting physical activity to those with lower limb absence. CLINICAL RELEVANCE: This research aims to inform prosthetic rehabilitation professionals and academics about an under-researched area within physical activity for health. This knowledge could help develop interventions with the aim of improving physical activity promotion and participation, and ultimately the health and well-being of people with limb absence.

Influences and trends of various shape-capture methods on outcomes in trans-tibial prosthetics: A systematic review.

INTRODUCTION: In trans-tibial prosthetics, shape-capture methods are employed to create a representation of the residuum. Shape-capture methods can be grouped into the categories of 'hands-on', 'hands-off' and computer-aided design. OBJECTIVE: This review examines the influences and trends of shape-capture methods on the outcomes of quality, comfort of user and clinical efficiency, in the population of trans-tibial prosthesis users. STUDY DESIGN: Systematic Review. METHOD: Databases and relevant journals were searched. Participants included trans-tibial prosthetics users/limb models. Interventions included shape-capture methods. Outcomes included quality, comfort of user and clinical efficiency. RESULTS: Overall, 22 papers were evaluated; 8 papers evaluated hands-on and hands-off methods, 2 evaluated computer-aided design and 12 evaluated measurement systems used with shape capture. No papers relating to clinical efficiency were found. CONCLUSION: Overall evidence was weak in suggesting that effects on outcomes were due to the sole influences of shape capture. However, studies suggest that hands-on methods are dependent on a prosthetist's skill. Hands-off methods, although repeatable, might still require experience to attain a good fit. Computer-aided design studies were mostly done on theoretical models. Shape-capture measurements require more consistent 'gold standards'. The relation between socket fit and comfort is still unclear. Overall, more research is required in each area. CLINICAL RELEVANCE: A good fitting prosthetic socket is crucial for efficient and comfortable use of a prosthesis. To attain the best chances of a good fit, it is important that the characteristics of the residuum are captured as accurately as possible during the initial "shape capture" stage. This paper attempts to categorize and evaluate the existing shape capture methods on their influence and trends on various outcomes - Quality of shape capture, comfort of user and clinical efficiency.

Evaluation of the hip joint contact force in subjects with Perthes based on OpenSIM.

The head of femoral bone is deformed in the subjects with Leg Calve Perthes disease (LCPD). This may be due to the excessive loads applied on it. There are no studies that report the hip joint contact force in subjects with LCPD. Therefore, the aim of this study was to evaluate the hip joint contact force in subjects with Perthes disease. Ten typically-developing (TD) children and 10 children with LCPD were recruited in this study. The kinematics and kinetics of the subjects were evaluated in 3D motion analysis. The hip joint contact force was approximated using OpenSIM software. Differences were determined with an independent t-test. There was a significant difference between walking speed of TD and Perthes subjects (63.8 (±8.1) and 57.4 (±7.0) m/min, respectively). The first peak of hip joint contact force was 4.8 (±1.7) N/BW in Perthes subjects, compared to 7.6 (±2.5) N/BW in TD subjects (p = 0.004). The peak hip joint contact force in mediolateral and anteroposterior directions was significantly lower in Perthes subjects (p < 0.05). The hip joint excursion was 40.0 (±5.6) and 46.4 (±8.5) degrees in Perthes and normal subjects, respectively (p = 0.03). The hip joint contact forces were lower in the subjects with Perthes disease. Therefore, it can be concluded that the strategies used by LCPD subjects were successful to decrease hip joint contact force.

Evaluation of the magnitude of hip joint deformation in subjects with avascular necrosis of the hip joint during walking with and without Scottish Rite orthosis.

The femoral head in subjects with leg calve perthes disease (LCPD) is generally considerably deformed. It is debatable whether this deformation is due to an increase in applied loads, a decrease in bone mineral density or a change in containment of articular surfaces. The aim of this study was to determine the influence of these factors on deformation of the femoral head. Two subjects with LCPD participated in this study. Subject motion and the forces applied on the affected leg were recorded using a motion analysis system (QualsisTM) and a Kistler force plate. OpenSim software was used to determine joint contact force of the hip joint whilst walking with and without a Scottish Rite orthosis. 3D Models of hip joints of both subjects were produced by Mimics software. The deformation of femoral bone was determined by Abaqus. Mean values of the force applied on the leg increased while walking with the orthosis. There was no difference between bone mineral density (BMD) of the femoral bone of normal and LCPD sides (p-value>0.05) and no difference between hip joint contact force of normal and LCPD sides. Hip joint containment appeared to decrease follow the use of the orthosis. It can be concluded that the deformation of femoral head in LCPD may not be due to change in BMD or applied load. Although the Scottish Rite orthosis is used mostly to increase hip joint containment, it appears to reduce hip joint contact area. It is recommended that a similar study is conducted using a higher number of subjects.

Evaluation of the influences of various force magnitudes and configurations on scoliotic curve correction using finite element analysis.

Scoliosis is a lateral curvature in the normally straight vertical line of the spine, and the curvature can be moderate to severe. Different treatment can be used based on severity and age of subjects, but most common treatment for this disease is using orthosis. To design orthosis types of force arrangement can be varied, from transverse loads to vertical loads or combination of them. But it is not well introduced how orthoses control scoliotic curve and how to achieve the maximum correction based on force configurations and magnitude. Therefore, it was aimed to determine the effect of various loads configurations and magnitudes on curve correction of a degenerative scoliotic subject. A scoliotic subject participated in this study. The CT-Scan of the subject was used to produce 3D model of spine. The 3D model of spine was produced by Mimics software and the finite element analysis and deformation of scoliotic curve of the spine under seven different forces and in three different conditions was determined by ABAQUS software. The Cobb angle in scoliosis curve decreased significantly by applying forces. In each condition depends on different forces, different corrections have been achieved. It can be concluded that the configurations of the force application mentioned in this study is effective to decrease the scoliosis curve. Although it is a case study, it can be used for a vast number of subjects to predict the correction of scoliosis curve before orthotic treatment. Moreover, it is recommended that this method and the outputs can be compared with clinical findings.

The effect that energy storage and return feet have on the propulsion of the body: a pilot study.

A variety of energy storage and return prosthetic feet are currently available for use within lower limb prostheses. Designs claim to provide a beneficial energy return during push-off, but the extent to which this occurs remains disputed. Techniques currently used to measure energy storage, dissipation and return within the structure of the prosthetic foot are debatable, with limited evidence to support substantial elastic energy storage and return from existing designs. The aim of this study was to evaluate the performance of energy storage and return foot designs through considering the ankle power during push-off and the effect on body centre of mass propulsion. To achieve this aim, the gait patterns of six trans-tibial prosthetic users wearing different designs of energy storage and return feet were analysed while ascending a ramp. Three examples of energy storage and return feet (suitable for moderate activity) were selected and randomly evaluated: the Blatchford's Epirus, Össur Assure and College Park Tribute feet. The power at the anatomical and mechanical ankle joints was integrated to evaluate the work done over the gait cycle. The direction of the inertial force, and therefore propulsion of the body centre of mass, was used to indicate the effect of the energy return by the energy storage and return feet. Results indicate that although energy storage and return feet may provide energy return, the work done around the prosthetic ankle indicates net power absorption. Therefore, the prosthetic limb is unable to contribute to the body centre of mass propulsion to the same extent as the biological limb.

Provision of prosthetic and orthotic services in low-income countries: a review of the literature.

BACKGROUND: Disability is inextricably linked to poverty. A total of 80% of the disabled population lives in low-income countries. The demand for prosthetic and orthotic services in these countries is increasing, and a variety of methods to provide services are currently used. OBJECTIVES: To assess current models of provision to facilitate sustainable, evidence-based prosthetic and orthotic services. STUDY DESIGN: Literature review. METHODS: A literature search was performed through Medline (Ovid), PubMed, ISI Web of Knowledge, EMBASE and RECAL Legacy using combinations of subject heading and text word searching strategies. Full-text publications were critically appraised and ranked according to the Scottish Intercollegiate Guidelines Network guidelines. RESULTS: Three areas were deemed pertinent to the research question. Studies were grouped into one or more of these categories based on the issues addressed: instigators, types of service provision, demographics and region-specific issues. It was found that many complex factors influence prosthetic and orthotic services in low-income countries. Demographic and regional idiosyncrasies require prosthetic and orthotic services to be tailored to address the specific needs of individual countries. CONCLUSIONS: The lack of and quality of available research made efficacy of methods used to provide services in low-income countries difficult to determine.

Motivations and barriers to prosthesis users participation in physical activity, exercise and sport: a review of the literature.

BACKGROUND: The UK will host the Paralympics in 2012 and the Commonwealth Games in 2014 showcasing the talents of elite athletes and aiming to inspire the population to become involved. However, low levels of physical activity are prevalent: only 40% of men and 28% of women meet the minimum UK physical activity recommendations. The population of people with limb absence is no exception. OBJECTIVES: To determine if people with amputation are participating in physical activity and sport; whether post-amputation activity levels match pre-amputation levels; and if there are motivations and barriers to participation. STUDY DESIGN: Literature review. METHODS: Five reviewers systematically searched all peer reviewed and gray literature in seven bibliographic databases and the Cochrane Library. RESULTS: Following rigorous elimination, 12 articles were finally included in the review and critically appraised. Four themes were identified: components; rehabilitation outcomes; body image; and motivations and barriers to participation. CONCLUSION: People with limb absence are not participating in physical activity conducive to health benefits, and only a minority participate in exercise and sports. Participation following amputation does not mirror that of pre-amputation levels, and more barriers than motivations exist to adopting or maintaining a physically active lifestyle.

Design of manikin for testing of residual-limb shape-capture method: technical note.

Consensus is still lacking on how best to capture the shape of a residual limb. Computer-aided design systems have not proven more accurate, repeatable, or reliable than traditional plaster of paris methods. Research is limited in design, relates to clinical trials, and is based on opinions and clinical experience. Many outcome measurements are based on qualitative estimations of prosthetic fit or patient feedback rather than quantitative measurements. Research must identify the most accurate, repeatable, and reliable methods for residual-limb shape capture under conditions most likely to enhance socket fit. Measurement is difficult because a reference grid is required for identifying the residual limb's axis for ensuring direct comparison. This article describes a manikin production method for testing the shape capture of the residual limb. Diameters and volume were measured at specific levels with a programmable computer numerical control milling machine and a displacement tool, with a combined accuracy of 5 micrometers.

Repeatability of a new observational gait score for unilateral lower limb amputees.

The aim of this study was to assess the repeatability of an observational gait analysis score that was developed specifically for unilateral amputees. Ten videotaped sequences were analysed by six experienced observers on two separate occasions. Data were analysed using percentage agreement, the kappa statistic and the coefficient of repeatability. The score demonstrated good intraobserver repeatability with an average repeatability coefficient of 3 (range 1.5-4.6). Interobserver repeatability was poor with a repeatability coefficient of 5.9. This score could be used in practice to assess amputees and is most repeatable if used by the same observer to evaluate changes in patients over time.

Head shape measurement standards and cranial orthoses in the treatment of infants with deformational plagiocephaly.

This review aims to determine how head shape is measured and describes the use of orthoses in the management of deformational plagiocephaly. A systematic review was conducted and papers published in English up to and including 2006 were sourced from nine databases. After initial screening, 20 papers were included; three literature reviews and 17 original papers. Of the original papers, eight concerned the method of head shape measurement. Measurements are important in determining clinical classification and treatment modality of deformational plagiocephaly. All studies were appraised and assigned a level of evidence according to the Scottish Intercollegiate Guidelines Network. Methodological quality was inadequate. Publications involving the use of cranial orthoses used convenience samples, were not blinded, and used different measurement techniques. No comparison groups were included and participants were not randomized. Evidence suggests that conservative treatments might reduce skull deformity although the quality is poor. Clinical studies investigating the use of cranial orthoses reported beneficial effects. Further research is required to identify the efficacy of cranial orthoses in the treatment of deformational plagiocephaly based on a standardized measurement technique to facilitate classification of this condition.