Project description:Wearable robotic devices can restore and enhance mobility. There is growing interest in designing devices that reduce the metabolic cost of walking; however, designers lack guidelines for which joints to assist and when to provide the assistance. To help address this problem, we used musculoskeletal simulation to predict how hypothetical devices affect muscle activity and metabolic cost when walking with heavy loads. We explored 7 massless devices, each providing unrestricted torque at one degree of freedom in one direction (hip abduction, hip flexion, hip extension, knee flexion, knee extension, ankle plantarflexion, or ankle dorsiflexion). We used the Computed Muscle Control algorithm in OpenSim to find device torque profiles that minimized the sum of squared muscle activations while tracking measured kinematics of loaded walking without assistance. We then examined the metabolic savings provided by each device, the corresponding device torque profiles, and the resulting changes in muscle activity. We found that the hip flexion, knee flexion, and hip abduction devices provided greater metabolic savings than the ankle plantarflexion device. The hip abduction device had the greatest ratio of metabolic savings to peak instantaneous positive device power, suggesting that frontal-plane hip assistance may be an efficient way to reduce metabolic cost. Overall, the device torque profiles generally differed from the corresponding net joint moment generated by muscles without assistance, and occasionally exceeded the net joint moment to reduce muscle activity at other degrees of freedom. Many devices affected the activity of muscles elsewhere in the limb; for example, the hip flexion device affected muscles that span the ankle joint. Our results may help experimentalists decide which joint motions to target when building devices and can provide intuition for how devices may interact with the musculoskeletal system. The simulations are freely available online, allowing others to reproduce and extend our work.
Project description:Tai Chi is an available method for the treatment of knee osteoarthritis (KOA). The impacts of Tai Chi on plantar loads of individuals with KOA are not fully understood. 46 participants with knee osteoarthritis were randomly assigned into the Tai Chi group (n = 23) or the control group (n = 23). The Tai Chi group attended a 6-month Tai Chi program, and the control group participated in a wellness education program. Novel Pedar-X system was used to collect the peak pressure (PP) and maximum force (MF) during walking before and 6 months after the intervention. Significant higher peak pressure and maximum force were observed in the 4th and 5th metatarsophalangeal joints in the Tai Chi group. However, there were significant declines in the peak pressure of the whole foot and the 2nd and 3rd metatarsophalangeal joints and maximum force of the heel in the control group. These results suggested that individuals with KOA might change the pattern of plantar loads during walking through Tai Chi, and plantar loads would be useful as a parameter to assess the effect of Tai Chi on knee osteoarthritis. This trial is registered with Clinical Trials: CHiCTR-TRC-13003264.
Project description:BackgroundWalking dysfunction is reported by two-thirds of persons with multiple sclerosis (MS). Assistive devices are frequently recommended to improve walking; however, it is uncommon to consider their psychosocial impact, although many users abandon their assistive devices. The psychosocial impact, walking, balance, and fatigue associated with three assistive devices were compared to guide clinical decision making.MethodsTwenty-five persons with MS (median Expanded Disability Status Scale score, 4.0; range, 2.5-6.0) who reported walking difficulty were trained in the use of three assistive devices-a single-point cane (SPC), a four-point cane (FPC), and a trekking pole (TP)-at 1- to 2-week intervals, then used the assistive device for their usual activities. Outcome measures included the Psychosocial Impact of Assistive Devices Scale (PIADS), the 6-Minute Walk Test (6MWT), walking speed, cadence, stride length, stride time, the 12-item Multiple Sclerosis Walking Scale (MSWS-12), the Activities-specific Balance Confidence (ABC) scale, the 5-item Modified Fatigue Impact Scale (MFIS-5), and a visual analogue scale of fatigue (VAS-F).ResultsThe SPC and TP were more positive in the PIADS adaptability, competence, and self-esteem subscales. The SPC and TP resulted in higher 6MWT, walking speed, cadence, stride length, stride time, and MSWS-12 scores compared with the FPC. No differences were found in ABC scale, MFIS-5, or VAS-F scores.ConclusionsParticipants reported more positive psychosocial impact, and walked faster and with higher quality, with the SPC and TP than with the FPC. Clinicians should consider suggesting an SPC or TP to patients who may benefit from assistive device use and for whom psychosocial impact is an important consideration.
Project description:BackgroundKnee osteoarthritis (KOA) is an irreversible degenerative disease that characterized by pain and abnormal gait. Radiography is typically used to detect KOA but has limitations. This study aimed to identify changes in plantar pressure that are associated with radiological knee osteoarthritis (ROA) and to validate them using machine learning algorithms.MethodsThis study included 92 participants with variable degrees of KOA. A modified Kellgren-Lawrence scale was used to classify participants into non-ROA and ROA groups. The total feature set included 210 dynamic plantar pressure features captured by a wearable in-shoe system as well as age, gender, height, weight, and body mass index. Filter and wrapper methods identified the optimal features, which were used to train five types of machine learning classification models for further validation: k-nearest neighbors (KNN), support vector machine (SVM), random forest (RF), AdaBoost, and eXtreme gradient boosting (XGBoost).ResultsAge, the standard deviation (SD) of the peak plantar pressure under the left lateral heel (f_L8PPP_std), the SD of the right second peak pressure (f_Rpeak2_std), and the SD of the variation in the anteroposterior displacement of center of pressure (COP) in the right foot (f_RYcopstd_std) were most associated with ROA. The RF model with an accuracy of 82.61% and F1 score of 0.8000 had the best generalization ability.ConclusionChanges in dynamic plantar pressure are promising mechanical biomarkers that distinguish between non-ROA and ROA. Combining a wearable in-shoe system with machine learning enables dynamic monitoring of KOA, which could help guide treatment plans.
Project description:BackgroundInjuries are the number one cause of death in children and cause significant morbidity. Common scenarios for injury include wheeled recreational devices (WRDs) that allow children to be mobile and independent (example ATV-all terrain vehicles, dirt bikes, bicycles, skateboards, and scooters). We present a case series review of these external causes of injury. This study aims to evaluate epidemiologic trends in WRD injuries and patterns in usage of protective gear.ResultsA total of 263 patients were identified as meeting criteria for inclusion with the following causes of injuries-103 bicycle, 73 ATV, 27 dirt bike, 14 skateboard, 13 motorcycle, 7 go carts, 3 hover board, 3 roller skates, 1 dune buggy, 1 motor scooter, 1 rip stick, and 1 tractor toy. Ages of patients ranged from 2 to 18 years of age with the greatest range being noted for bicycles (2-17 years) and motorcycles (3-18 years). The mean age was higher for motorcycle and skateboard (12.9 and 11.6, respectively) and lowest for scooter and bicycle (8.3 and 9.2, respectively). The majority of [overall study (97%) and for each mode of transportation] patients were Caucasian, which is in contrast to our overall ED population, which is only 42% Caucasian. The majority of patients were male [190 (72%)]. Over half of the overall patients, 159 of the 263 (60%), were not wearing a helmet (with only 10 charts having no documentation of helmet use). In regard to ATV riders specifically, 58% were not wearing helmets at the time of injury, with an additional 5 patients who reported their helmet came off. The lowest percentage of riders reporting appropriate helmet use was skateboarders with only 21% wearing helmets, and the highest percentage was dirt bike riders with 74% reporting helmet use.ConclusionCommon scenarios for injury include WRDs that allow children to be mobile and independent. Most of these injuries were found in Caucasian males between the ages of 9-12 with low rates of helmet use. This study adds to the literature with a description of the breadth of products children use and are injured while using.
Project description:PurposeA primary goal for aging policy is to optimize independence in later life. We estimate the cross-sectional association between physical and social challenge in the home environment and use of assistive devices (AD) for mobility in the home, controlling for lower extremity physical performance (short physical performance battery [SPPB]) and other factors.Design and methodsData are from the Women's Health and Aging Study I, a prospective study of the factors related to physical disability in a sample of moderately to severely disabled older women. We describe these associations in the baseline sample overall and also within subsets who do and do not have both a baseline and a 3-year follow-up observation.ResultsOn average, physical challenge in the home environment is inversely associated with level of AD use (p < .05) in the overall sample, independent of SPPB, living alone, and other factors. We do not find a significant (p < .05) association between social challenge and the level of AD use in the overall sample. Findings by follow-up responder status were similar (with minor variability).ImplicationsFuture cohorts who are better educated and more receptive to technology may confront challenges in the home environment that limit their ability to age in place. Our findings suggest that the physical challenges of the home are significantly related to AD use. Future analyses that explore the mechanisms of the home environment as a source of challenges to independent functioning could help in the design of future interventions for these cohorts as they age.
Project description:Prosthetic alignment is an important factor in the overall fit and performance of a lower-limb prosthesis. However, the association between prosthetic alignment and control strategies used by persons with transfemoral amputation to coordinate the movement of a passive prosthetic knee is poorly understood. This study investigated the biomechanical response of persons with transfemoral amputation to systematic perturbations in knee joint alignment during a level walking task. Quantitative gait data were collected for three alignment conditions: bench alignment, 2 cm anterior knee translation (ANT), and 2 cm posterior knee translation (POST). In response to a destabilizing alignment perturbation (i.e., the ANT condition), participants significantly increased their early-stance hip extension moment, confirming that persons with transfemoral amputation rely on a hip extensor strategy to maintain knee joint stability. However, participants also decreased the rate at which they loaded their prosthesis, decreased their affected-side step length, increased their trunk flexion, and maintained their prosthesis in a more vertical posture at the time of opposite toe off. Collectively, these results suggest that persons with transfemoral amputation rely on a combination of strategies to coordinate stance-phase knee flexion. Further, comparatively few significant changes were observed in response to the POST condition, suggesting that a bias toward posterior alignment may have fewer implications in terms of stance-phase, knee joint control.
Project description:ObjectiveTo investigate which assistive devices people with advanced cancer have and whether they are in use. In addition, to explore the characteristics of people with advanced cancer who have unmet needs for assistive devices.MethodsThis descriptive cross-sectional study used data from a randomised controlled trial evaluating efficacy of an occupational therapy-based intervention. Participants were 237 people with advanced cancer. Data were collected by means of instruments about demography, functioning and assistive devices.ResultsThe most frequent assistive devices possessed by the participants were as follows: (1) small aids for dressing (47%), (2) Pillow for positioning (40%) and (3) electrically operated adjustable bed (39%). The prevalence of assistive devices was 92% (95% confidence interval [CI]: 88%-95%) with 14.2% non-use, largest for trolley tables (50%). In all, 27.4% of the participants were found to have unmet needs for assistive devices. These participants had similar characteristics to the other participants except from lower activity of daily living (ADL) ability (p values = <0.001).ConclusionThe assistive devices possessed by the participants were primarily for positioning and resting, and most were in use. More than a fourth of the participants had unmet needs for assistive devices and were characterised by lower ADL ability.
Project description:ObjectivesTo provide a profile of older adults who successfully accommodate declines in capacity by using assistive devices.MethodUsing the National Health and Aging Trends Study, we provide national estimates of prevalent, incident, and persistent successful accommodation of mobility and self-care activity limitations. For incident and persistent accommodation groups, we describe their subjective wellbeing and participation restrictions, health and functioning, demographic and socioeconomic characteristics, and acquisition of assistive devices and environmental features. We estimate regression models predicting incident and persistent successful accommodation and the extent of wellbeing and participation restrictions for incident and persistent groups (vs. those who are fully able).ResultsNearly one-quarter of older adults have put in place accommodations that allow them to carry out daily activities with no assistance or difficulty. In adjusted models, incident and persistent successful accommodation is more common for those ages 80-89, those with more children, and those living in homes with environmental features already installed; wellbeing levels for these groups are similar and participation restrictions only slightly below those who are fully able.DiscussionA focus on facilitating successful accommodation among those who experience declines in capacity may be an effective means of promoting participation and wellbeing in later life.
Project description:BACKGROUND:Aerobic training has the potential to restore function, stimulate brain repair, and reduce inflammation in people with Multiple Sclerosis (MS). However, disability, fatigue, and heat sensitivity are major barriers to exercise for people with MS. We aimed to determine the feasibility of conducting vigorous harness-supported treadmill training in a room cooled to 16 °C (10 weeks; 3times/week) and examine the longer-term effects on markers of function, brain repair, and inflammation among those using ambulatory aids. METHODS:Ten participants (9 females) aged 29 to 74 years with an Expanded Disability Status Scale ranging from 6 to 7 underwent training (40 to 65% heart rate reserve) starting at 80% self-selected walking speed. Feasibility of conducting vigorous training was assessed using a checklist, which included attendance rates, number of missed appointments, reasons for not attending, adverse events, safety hazards during training, reasons for dropout, tolerance to training load, subjective reporting of symptom worsening during and after exercise, and physiological responses to exercise. Functional outcomes were assessed before, after, and 3 months after training. Walking ability was measured using Timed 25 Foot Walk test and on an instrumented walkway at both fast and self-selected speeds. Fatigue was measured using fatigue/energy/vitality sub-scale of 36-Item Short-Form (SF-36) Health Survey, Fatigue Severity Scale, modified Fatigue Impact Scale. Aerobic fitness (maximal oxygen consumption) was measured using maximal graded exercise test (GXT). Quality-of-life was measured using SF-36 Health Survey. Serum levels of neurotrophin (brain-derived neurotrophic factor) and cytokine (interleukin-6) were assessed before and after GXT. RESULTS:Eight of the ten participants completed training (attendance rates ≥ 80%). No adverse events were observed. Fast walking speed (cm/s), gait quality (double-support (%)) while walking at self-selected speed, fatigue (modified Fatigue Impact Scale), fitness (maximal workload achieved during GXT), and quality-of-life (physical functioning sub-scale of SF-36) improved significantly after training, and improvements were sustained after 3-months. Improvements in fitness (maximal respiratory exchange ratio and maximal oxygen consumption during GXT) were associated with increased brain-derived neurotrophic factor and decreased interleukin-6. CONCLUSION:Vigorous cool room training is feasible and can potentially improve walking, fatigue, fitness, and quality-of-life among people with moderate to severe MS-related disability. TRIAL REGISTRATION:The study was approved by the Newfoundland and Labrador Health Research Ethics Board (reference number: 2018.088) on 11/07/2018 prior to the enrollment of first participant (retrospectively registered at ClinicalTrials.gov: NCT04066972. Registered on 26 August 2019.