Yusuke Komaba

Quantification of postural control deficits in patients with recent concussion: An inertial-sensor based approach

Background: The aim of this study was to quantify postural control ability in a group with concussion compared with a healthy control group. Method: Fifteen concussion patients (4 females, 11 males) and a group of fifteen age‐ and sex‐matched controls were recruited. Participants were tested during the performance of the three stance variants (bilateral, tandem and unilateral) of the balance error scoring system standing on a force place, while wearing an inertial measurement unit placed at the posterior aspect of the sacrum. Findings: The area of postural sway was computed using the force‐plate and the ‘95% ellipsoid volume of sway’ was computed from the accelerometer data. Concussed patients exhibited increased sway area (1513 mm2 [95% CI: 935 to 2091 mm2] vs 646 mm2 [95% CI: 519 to 772 mm2]; p = 0.02) and sway volume (9.46 m3 s− 6 [95% CI: 8.02 to 19.94 m3 s− 6] vs 2.68 m3 s− 6 [95% CI: 1.81 to 3.55 m3 s− 6]; p = 0.01) in the bilateral stance position of the balance error scoring system. The sway volume metric also had excellent accuracy in identifying task ‘errors’ (tandem stance: 91% accuracy [95% CI: 85–96%], p < 0.001; unilateral stance: 91% accuracy [95% CI: 86–96%], p < 0.001). Interpretation: Individuals with concussion display increased postural sway during bilateral stance. The sway volume that was calculated from the accelerometer data not only differentiated a group with concussion from a healthy control group, but successfully identified when task errors had occurred. This may be of value in the development of a pitch‐side assessment system for concussion. Highlights:Postural control performance is evaluated in a cohort with recent concussion.Traditional and novel technologies were used to measure performance.Postural ‘sway’ was quantified with a force plate and a wearable sensor.Concussed patients exhibit increased sway in bilateral stance.These alterations are likely reflective of impaired sensorimotor control.

Context aware falls risk assessment: A case study comparison

This paper describes three retrospective case studies to illustrate the potential clinical value of a system capable of capturing objective gait metrics and environment data from older adults with a history of falls while they go about their daily lives. Participants in this study wore an inertial sensor above each ankle and a wearable camera around their neck for seven consecutive days. Selected metrics are presented to illustrate scenarios where the data collected by the system could be of clinical value. Evidence suggests that obtaining objective gait metrics and environment data from older adults may not only allow healthcare professionals to assess gait more accurately, but also to design treatment plans and falls prevention strategies that are more specifically tailored to each individual.

Quantification of postural control deficits in patients with recent concussion: an inertial-sensor based approach

Objective To quantify postural control ability in a group with concussion compared with a ‘healthy’ control group. Design Case-control study. Setting University Biomechanics Laboratory. Participants Fifteen concussion patients (4 females, 11 males) and a group of fifteen age- and sex- matched controls. Participants were excluded if they had any: lower extremity injury that may affect gait; history of cognitive deficiencies; history of ≥3 previous concussions; loss of consciousness following the concussion for >1 minute; a previously documented concussion in the previous year Independent variable Group; Task (3 stance variants of the Balance Error Scoring System [BESS]) Outcome measures Sway area as computed using a force-plate and sway volume as computed from an accelerometer placed on the sacrum during performance of the BESS. Main results Concussed patients exhibited increased sway area (1500 mm2 [95% CI: 900 to 2000 mm2] vs 650 mm2 [95% CI: 520 to 780 mm2] p=0.02) and sway volume (9.5 m3s–6 [95%CI: 8 to 20 m3s–6] vs 2.80 m3s–6 [95% CI: 1.8 to 3.6 m3s–6]) in the bilateral stance position of the BESS. The sway volume metric also had excellent accuracy in identifying task ‘errors’ (tandem stance: 95% CI: 80–96%, p<0.001; unilateral stance: 95% CI: 85–95%, p<0.001). Conclusions Individuals with concussion display increased postural sway during bilateral stance. The sway volume that was calculated from the accelerometer data not only differentiated a group with concussion from a healthy control group, but successfully identified when task errors had occurred. This may be of value in the development of a pitch-side assessment system for concussion. Competing interests None.

Context focused older adult mobility and gait assessment

This paper presents an initial overview of insights gained into how older adults mobilize in the home and community, based on data from inertial sensors which were worn by study participants over a 7-day period. The addition of a wearable camera provided additional contextual information which can be used to assess mobility and understand the factors that influence it in the free living environment. Seven days of data collected from a group of older adults who had experienced one or more falls in the previous six months was compared to that of a control group with no history of falling. Results showed that both groups spent relatively little time walking in challenging environmental conditions, and that the fallers spent significantly less time walking under regular conditions (no effect on gait) and outdoors. Analysis of gait metrics showed that the fallers were slightly slower in general, and more noticeable differences were observed when the participants were regrouped according to mobility levels determined from baseline assessments using traditional methods.