Design of SmartWalk for Estimating Implication of Pathway With Turn and Task Condition on Postural and Gait Indices: Relevance to Fear of Fall.

Fear of Fall (FoF) is often associated with postural and gait abnormalities leading to decreased mobility in individuals with Parkinson's Disease (PD). The variability in knee flexion (postural index) during heel-strike and toe-off events while walking can be related to one's FoF. Depending on the progression of the disease, gait abnormality can be manifested as start/turn/stop hesitation, etc. adversely affecting one's cadence along with an inability to transfer weight from one leg to the other. Also, task demands can have implications on one's gait and posture. Given that individuals with PD often suffer from FoF and their dynamic balance is affected by task conditions and pathways, in- depth investigation is warranted to understand the implications of task condition and pathways on one's gait and posture. This necessitates use of portable, wearable device that can capture one's gait-related indices and knee flexion in free-living conditions. Here, we have designed a portable, wearable and cost-effective device (SmartWalk) comprising of instrumented Shoes integrated with knee flexion recorder units. Results of our study with age-matched groups of healthy individuals (GrpH) and those with PD (GrpPD) showed the potential of SmartWalk to estimate the implication of task condition, pathways (with and without turn) and pathway segments (straight and turn) on one's knee flexion and gait with relevance to FoF. The knee flexion and gait-related indices were found to strongly corroborate with clinical measure related to FoF, particularly for GrpPD, serving as pre-clinical inputs for clinicians.

Portable Electromyogram-sensitive System for Assessment of Fear of Fall: Relevance of Gait Phases for Post-Stroke Patients.

Post-stroke patients often suffer from gait deficits along with Fear of Fall (FoF) that adversely affect their ambulation. The FoF has been reported to be negatively correlated with one's performance in daily life. Clinical scales, e.g., Falls Efficacy Scale are often used to assess one's FoF. Though powerful, it can suffer from subjectivity. Thus, it is important to have reliable assessment of FoF. Motivated by this, we used one's lower limb muscle activation during specific gait phases to assess one's FoF. For this, we developed a portable electromyogram-sensitive system that can synchronously measure one's muscle activation along with gait phases. We conducted an experimental study with post-stroke patients and age-matched healthy controls who walked under Dual-Task condition. We investigated the lower limb muscle (Gastrocnemius Lateralis (GM) and Tibialis Anterior (TA)) activation during Loading Response, Terminal Stance and Initial Swing phases of gait, associated with slips contributing to FoF. Results show that our system could quantify the disparity (∆) in muscle activation between the affected and unaffected sides of patients (∆ =  âˆ¼ 84% during Loading response for both GM and TA, ~32%for GM during Terminal Stance and TA during Initial Swing) which was considerably higher than that between dominant and non-dominant sides of healthy controls. This might infer reduced dynamic stability of patients leading to their FoF. Also, muscle activation could classify patients from healthy controls with 90% accuracy during Loading Response and Initial Swing phases with clinical relevance in diagnostics and monitoring rehabilitation outcomes. Clinical Relevance- This study indicated that our system has potential to be utilized as a tool for diagnostic and monitoring rehabilitation outcomes as it can quantify the residual muscle ability of the post-stroke patients during gait.

Smart Wearable Device for Quantification of Risk of Fall: Exploring Role of Gait Phases and Knee Bending Angle for Parkinson's Patients.

Gait disturbances with falls are common among patients with Parkinson's disease. Falls commonly occur from slips while walking on pathways with turns. Gait phases namely Loading Response and Terminal Stance are linked with forward and backward slips. Also, postural deformities (connected with knee joint angles) are debilitating symptoms of Parkinson's patients and are related with falls. Here, we have focused on exploring the contribution of Loading Response and Terminal Stance to risk of fall along with the relevance of postural deformity (e.g., knee bending) while an individual walked overground on pathways (with 0° and 180° turn) under dual task condition. For this, we have used a wearable device consisting of a pair of Sensored shoes and Knee Bending Angle Recorder Units. The device was used to compute Coefficient of Variation of knee bending angle during different gait phases as an indicator of one's risk of fall that corroborated with clinical measure. Clinical Relevance- A study with age and gender matched healthy and Parkinson's individuals indicated the importance of Loading Response and pathway turn while assessing risk of fall. This can serve as important pre-clinical input while designing intervention paradigms.

The Implication of Pathway Turn and Task Condition on Gait Quantified Using SmartWalk: Changes With Age and Parkinson's Disease With Relevance to Postural Strategy and Risk of Fall.

One's gait can be affected by aging, pathway with turns, task demands, etc., causing changes in gait-related indices and knee flexion (influencing posture). Walking on pathways with turns threatens stability, affecting one's gait-related indices and posture. The ability to overcome such deficits is compromised with age and neurological disorders, e.g., Parkinson's Disease (PD) leading to falls. Also, task demands imposed by single and dual-task (e.g., counting backward while walking) conditions affect the gait of individuals using different postural strategies varying with age and neurological disorder. Existing research has investigated either the effect of the pathway with turn or task condition on one's gait. However, none (to our knowledge) have explored the differentiated implications of the pathway with turn and task conditions on one's gait-related indices and knee flexion while walking. Our study had two phases with 30 participants. Phase 1 had healthy adults (young and old) and Phase 2 had age and gender-matched healthy elderly and individuals with Parkinson's disease (PD) who walked on pathways having turns under single and dual-task conditions. We analysed gait in terms of (i) gait-related indices (Phases 1 and 2) and (ii) knee flexion (Phase 2). Also, we analysed one's counting performance during dual task. One's gait-related indices and knee flexion were measured using a portable gait quantifier. The aim was to (i)understand whether both pathways with turn and task conditions are equally effective in affecting the gait of (a)individuals of varying ages and (b) gender-matched healthy older adults and individuals with PD, (ii)study variations of knee joint angles while walking on pathways having turns (under different task conditions) in terms of its clinical relevance, and (iii) explore the implication of pathway with turn on counting performance (with relevance to postural strategy) with varying age and PD. Results indicated that for the younger group, the task condition caused statistical variations in gait-related indices. For the older group, both pathways with turn and task conditions had statistical implications on gait-related indices. Additionally, individuals with PD demonstrated a higher variation in knee flexion than their healthy counterparts. Again, pathways with varying turns elicited variations in counting performance indicating different postural strategies being employed by the three groups.

Wearable Technology for Evaluation of Risk of Falls.

One's risk of fall can be quantified in terms of variability in one's gait, reflecting a loss of automatic rhythm of one's gait. In gait analysis, variability is commonly understood in terms of the fluctuation in the kinematic, kinetic, spatio-temporal, or physiological information. Here, we have focused on the estimation of knee joint angle (kinematic variable) synchronized with some of the kinetic and spatio-temporal gait parameters while an individual walked overground. Our system consisted of a pair of shoes with instrumented insoles and knee flexion/extension recorder unit having bend sensors. In addition, we have used the Coefficient of Variation for estimating the variability in the knee flexion/extension angle while walking overground as an indicator of the risk of fall. A study with healthy individuals (young and old) walking overground on pathways having 00 and 1800 turning angles indicated the feasibility of our wearable system to compute the variability in knee flexion/extension angle as an indicator of the risk of fall.