Effects of Motor Skill-Based Training on Wheelchair Propulsion Biomechanics in Older Adults: A Randomized Controlled Trial.

OBJECTIVE: To identify whether motor skill-based training improves wheeling biomechanics in older adults and whether transfer or retention occurs. DESIGN: Randomized controlled trial. SETTING: Human mobility laboratory. PARTICIPANTS: Able-bodied older adults 50 years and older deemed ready to participate in physical activity (N=34). INTERVENTION: Participants were randomized to 1 of 3 groups: experimental group with 6 motor skill-based training sessions, active control group with dose-matched uninstructed practice, and the inactive control group (no training or practice). The experimental group's training sessions consisted of two 5-minute blocks of wheelchair propulsion training, separated by a 5-minute break, for a total of 60 minutes of wheeling. Breaks included education and discussion related to wheelchair propulsion. Training focused on increasing push angle, decreasing push frequency, decreasing negative braking forces, and using a circular wheeling pattern with smooth pushes. MAIN OUTCOME MEASURES: Temporal spatial and kinetic variables (ie, push angle, push frequency, total and tangential forces, negative force) were evaluated during steady-state wheeling and biomechanical variables were assessed with the SmartWheel Clinical Protocol to identify transfer. RESULTS: The training group significantly increased push angle and decreased push frequency compared with the practice (P<.05) and control groups (P<.05), which were retained over time and transferred to overground wheeling on tile (P≤.05). The dose-matched practice group did not differ from the inactive control group for any variables (P>.05). CONCLUSIONS: Older adults improve select biomechanical variables following motor skill-based training, which are retained over time and transfer to overground wheeling. Participants in the active control group did not improve with uninstructed practice compared with the inactive control group.

Prior experience does not alter modulation of cutaneous reflexes during manual wheeling and symmetrical arm cycling.

Previous research has reported that training and experience influence H-reflex amplitude during rhythmic activity; however, little research has yet examined the influence of training on cutaneous reflexes. Manual wheelchair users (MWUs) depend on their arms for locomotion. We postulated that the daily dependence and high amount of use of the arms for mobility in MWUs would show differences in cutaneous reflex modulation during upper limb cyclic movements compared with able-bodied control subjects. We hypothesized that MWUs would demonstrate increased reflex response amplitudes for both manual wheeling and symmetrical arm cycling tasks. The superficial radial nerve was stimulated randomly at different points of the movement cycle of manual wheeling and symmetrical arm cycling in MWUs and able-bodied subjects naive to wheeling. Our results showed that there were no differences in amplitude modulation of early- or middle-latency cutaneous reflexes between the able-bodied group and the MWU group. However, there were several differences in amplitude modulation of cutaneous reflexes between tasks (manual wheeling and symmetrical arm cycling). Specifically, differences were observed in early-latency responses in the anterior and posterior deltoid muscles and biceps and triceps brachii as well as in middle-latency responses in the anterior and posterior deltoid. These data suggest that manual wheeling experience does not modify the pattern of cutaneous reflex amplitude modulation during manual wheeling. The differences in amplitude modulation of cutaneous reflexes between tasks may be a result of mechanical differences (i.e., hand contact) between tasks.

Test-retest reliability and minimal detectable change of the SmartWheel clinical protocol.

OBJECTIVES: (1) To quantify the intra- and intersession reliability and minimal detectable change (MDC) of the SmartWheel clinical protocol (SCP) and (2) to compare the reliability of the SCP between experienced and naïve wheelchair users. DESIGN: Test-retest study. SETTING: Biomechanics laboratory. PARTICIPANTS: Manual wheelchair users (WCUs) (n=10) with 1 to 32 years of wheeling experience and able-bodied (AB) naïve users (n=15). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Wheelchair propulsion parameters including average peak force, push frequency, push length, and velocity were measured according to the SCP but with 5 trials per session, for 2 sessions. WCUs and AB users were analyzed separately. Intraclass correlation coefficients ([ICC](2,1) and ICC(2,5)) were calculated to assess intrasession reliability. ICC(2,1) and MDC (with 95% confidence) were calculated for each SCP parameter using a single trial from each session and with the mean of 5 repeated measures to evaluate intersession reliability. RESULTS: Intra- and intersession reliability for WCU parameters ranged from high to very high correlation (ICC range, .70-.99). For AB parameters, intrasession ICC(2,1) ranged from moderate to very high (ICC range, .50-.92), while intersession ICC(2,1) indicated low to very high correlation (ICC range, .25-.90). Estimates of standard error of measurement and MDC were provided for each parameter. For both WCUs and AB users, using the means from 5 trials increased intra- and intersession ICC and decreased MDC values. All MDC values were lower for WCUs compared with AB users. CONCLUSIONS: The SCP is a reliable method for assessing propulsion parameters in WCUs, even if just 1 trial is taken per session. AB users showed lower intra- and intersession reliability compared with WCUs. Therefore, for AB users or individuals with minimal wheeling experience, averaging multiple trials is recommended for the SCP.

Expectations of a Health-Related Mobile Self-Management App Intervention Among Individuals With Spinal Cord Injury.

Background: Our research team developed a mobile application (app) to facilitate health-related self-management behaviors for secondary conditions among individuals with spinal cord injury (SCI). To facilitate mobile app adoption and ongoing use into the community, it is important to understand potential users' expectations and needs. Objectives: The primary objective of this study was to explore user expectations of a mobile app intervention designed to facilitate self-management behavior among individuals with SCI. Methods: Data were collected via one-on-one, semi-structured interviews with a subsample of 20 community-dwelling participants enrolled in a larger, clinical trial. Analysis of the transcripts was undertaken using a six-phase process of thematic analysis. Results: Our analysis identified three main themes for expectations of the mobile app intervention. The first theme, desiring better health outcomes, identified participants' expectation of being able to improve their psychological, behavioral, and physical health outcomes and reduce associated secondary conditions. The second theme, wanting to learn about the mobile app's potential, identified participants' interest in exploring the functionality of the app and its ability to promote new experiences in health management. The third theme, desiring greater personal autonomy and social participation, identified participants' desire to improve their understanding of their health and the expectation for the app to facilitate social engagement with others in the community. Conclusion: By exploring end-users' expectations, these findings may have short-term effects on improving continued mobile health app use among SCI populations and long-term effects on informing future development of mobile app interventions among chronic disease populations.

The Effect of External Power Output and Its Reliability on Propulsion Technique Variables in Wheelchair Users With Spinal Cord Injury.

The purpose of this study was to assess 1) how treadmill slope variance affected external power output (PO) and propulsion technique reliability; and 2) how PO is associated with propulsion technique. Eighteen individuals with spinal cord injury performed two wheelchair treadmill exercise blocks (0% and 1% treadmill slope, standardized velocity) twice on two separate days. PO, velocity, and 14 propulsion technique variables were measured. In a follow-up study, N = 29 performed wheelchair treadmill drag tests. Target and actual slope were documented and PO, intraclass correlation coefficients (ICC) and smallest detectable differences (SDD) were calculated. Within and between visits, the reliability study ICCs were perfect for velocity (1.0), weak for PO (0.33-0.46), and acceptable (>0.70) for five (0% slope) and 10 (1% slope) propulsion technique variables, resulting in SDDs of 35-196%. Measured PO explained 56-90% of the variance in key propulsion technique variables. In the follow-up, PO ICCs were weak (0.43) and SDDs high. Bias between target and actual slope appeared random. In conclusion, PO variability accounts for 50-90% of the variability in propulsion technique variables when speed and wheelchair set-up are held constant. Therefore, small differences in PO between interventions could mask the effect of the interventions on propulsion technique.

Efficiency and perceived exertion of manual wheelchair propulsion: a physiological comparison of push vs pull wheeling.

Manual wheelchair users face a high prevalence of upper extremity pain and injuries associated with poor biomechanics and the relatively low mechanical efficiency of conventional push wheeling. Recently developed geared wheels, which permit the wheelchair user to propel forwards by pulling at the handrims using a 'rowing' motion, have been speculated to improve ergonomics and reduce operational energy costs. This study compared the gross mechanical efficiency (GME) and perceived exertion (RPE) of these geared wheels to standard wheelchair wheels after a motor skill-based training session was conducted to familiarise participants with using both wheels. Fourteen able-bodied males were enrolled in the study. A within-participants, repeated-measures design was used to assess oxygen uptake (VO2), respiratory exchange ratio (RER), energy expenditure (En) and RPE during 5-minute, steady-state wheeling trials. Total external power output (Pext) was obtained using a drag test protocol for comparison over En to determine GME ratio. Stroke frequency and movement pattern were assessed through video tracking and propulsion testing. Although geared wheels required fewer strokes, standard wheels resulted in significantly lower VO2, RPE and En (p ≤ 0.001). These findings suggest overall that standard wheels were more mechanically efficient, likely due to internal energy loss of the geared wheel system.

Injuries Associated with Crutch Use: A Narrative Review.

Crutches are commonly prescribed in physiatric settings to help offload the lower extremities. Crutch use, however, results in abnormal and repetitive weight-bearing through the upper extremities that may result in secondary injury. This narrative review investigates injury types and risk factors associated with crutch use in order to guide healthcare providers on injury prevention strategies. Medline, EMBASE, CINAHL, and the Cochrane Library were systematically reviewed for publications between 1950 and 2018 on neurological, musculoskeletal, or vascular complications associated with crutch use. Titles and abstracts (n = 2395) were screened by two authors. Sixty studies were eligible. Articles were reviewed for level of evidence, crutch type, participant characteristics, and injury characteristics. There were 42 axillary crutch studies, 12 forearm crutch studies, and 6 studies that did not specify crutch type. These studies incorporated 622 individuals, and most were case series or case reports (n = 54). Axillary crutch use was most commonly associated with axillobrachial arterial complications due to pressure from the axillary bar (n = 34). Forearm crutch use was most commonly associated with compressive neuropathies due to pressure from the forearm cuff (n = 6). Improper crutch fitting and/or use were identified as contributing factors to injury in 22 cases. Duration of crutch use and medical comorbidities also influenced the types of injuries seen. There are rare but potentially serious complications associated with crutch use. When prescribing crutches, clinicians should ensure they are properly fit, engage in appropriate gait training, be aware of common crutch-related injuries, and consider potential patient-specific injury risk factors in order to minimize injury risk.

Implementing a self-management mobile app for spinal cord injury during inpatient rehabilitation and following community discharge: A feasibility study.

Objective: To determine the feasibility of implementing and evaluating a self-management mobile app for spinal cord injury (SCI) during inpatient rehabilitation and following community discharge. Design: Pilot feasibility study. Setting: Rehabilitation hospital and community. Participants: Inpatients from rehabilitation hospital following admission for their first SCI. Intervention: A mobile app was developed to facilitate self-management following SCI. The app consisted of 18 tools focusing on goal setting, tracking various health aspects, and identifying confidence regarding components of self-management. In-person training and follow-up sessions were conducted during inpatient rehabilitation and follow-up calls were provided after participants were discharged into the community. Main outcome measures: Participants completed outcome measures at baseline, community discharge, and 3-months post discharge. This study focused on feasibility indicators including recruitment, retention, respondent characteristics, adherence, and app usage. Additionally, participants' self-management confidence relating to SCI (e.g. medication, skin, bladder, pain) was evaluated over time. Results: Twenty participants (median age 39, IQR: 31 years, 85% male) enrolled in the study. Participants' Spinal Cord Injury Independence Measure (SCIM-III) median score was 23 and IQR was 33 (range: 7-84), which did not correlate with app usage. Retention from admission to discharge was 85% and 70% from discharge to 3-months post discharge. Individuals in the study who used the app entered data an average of 1.7x/day in rehabilitation (n = 17), and 0.5x/day in the community (n = 7). Participants' bowel self-management confidence improved between admission and discharge (P < 0.01). Conclusions: Feasibility indicators support a larger clinical trial during inpatient rehabilitation; however, there were challenges with retention and adherence following community discharge.

Exploring the ecological validity and variability of a 10-min bout of wheeling.

PURPOSE: To determine the ecological validity of using able-bodied participants to perform a 10-min wheeling trial by (1) evaluating changes in biomechanics over the trial in manual wheelchair users and able-bodied participants naïve to wheeling and (2) describing differences in changes and variability between groups. MATERIALS AND METHODS: Manual wheelchair users (n = 7, 2-27 years' experience) and able-bodied participants (n = 11) wheeled for 10 min. Kinetic and temporal variables were collected and averaged over each minute, while wheeling strategy (movement pattern) was categorized at minutes 1 and 10. RESULTS: There was a main effect of time for push angle, and a main effect of group for average push angle, tangential force and total force. Manual wheelchair users used larger push angles and forces compared to able-bodied participants. Surprisingly, intercycle variability did not differ between groups. CONCLUSION: Using able-bodied participants to represent manual wheelchair users performing a 10-min wheeling trial is not ecologically valid and caution should be used when interpreting push angle and forces applied to the pushrim. Considering that push angle was the only variable that demonstrated a main effect of time, long durations (e.g., 10 min) of wheeling may be appropriate for use in study designs acknowledging potential changes in wheeling strategy and push angle. Implications for Rehabilitation Some experienced wheelchair users and non-wheelchair users modify their movement pattern from an arc to a circular pattern within a 10-min wheeling trial. There are clear biomechanical differences in push angle and forces applied to the pushrim between wheelchair users with experience and able-bodied non-wheelchair users. Able-bodied participants who have no prior manual wheeling experience are no more variable than long-term wheelchair users. Variability may play an important role in wheelchair propulsion.

Goal satisfaction improves with individualized powered wheelchair skills training.

PURPOSE: To determine improvements in goal satisfaction following individualized mobility-related powered wheelchair skills training and whether changes in satisfaction are maintained 3 months post-training. MATERIALS AND METHODS: Seventeen powered wheelchair users, from two centres, who were randomized to the training intervention from a larger multicentre study, were included in this secondary analysis. The intervention consisted of five 30-min individualized Wheelchair Skills Training Program sessions. Participants rated their current satisfaction with each of their goals from 0 to 10 (10 being the highest) prior to training, immediately after the intervention, and approximately 3 months following the intervention. Themes relating to the participants' goals were also explored. RESULTS: Goal satisfaction scores improved statistically (p < .001) from baseline (4.7 ± 1.9) to immediately following training (8.0 ± 1.0) and were maintained 3 months (8.3 ± 1.2) following the intervention. Participants' goal satisfaction scores were not significantly correlated with goal attainment scores recorded by the trainer (r = 0.387, n = 17, p = .125). The majority of goals set fell into the broader "manoeuvring" category. CONCLUSION: Goal satisfaction following the Wheelchair Skills Training Program improved years after initially learning how to operate a powered wheelchair. The five training sessions were effective in improving goal satisfaction. The quantification of goal satisfaction appears to be a sensitive outcome for powered wheelchair users undergoing mobility-related training. Implications for rehabilitation Goal satisfaction improved following the Wheelchair Skills Training Program. Even with years of powered wheelchair experience, the majority of goals set fell into the broader "manoeuvring" category. An individual's goal satisfaction may not correlate with whether they have attained their goal as determined by a trainer.

The influence of a polymer damper on swing-through crutch gait biomechanics.

Forearm crutch technology has evolved slowly compared to other assistive mobility devices, despite the highly repetitive nature of forearm crutch gait and the high incidence of overuse injuries. Using 13 able-bodied volunteers between the ages of 19 and 27, we compared the ground reaction forces of a novel crutch design featuring an elastomeric polymer situated below the handle to an identical design without a damper system and to a commercially available generic rigid forearm crutch model. There were no differences in peak vertical force or impulse between crutches. The crutch with the damper system demonstrated a significantly smaller peak braking force and impulse compared to the generic forearm crutch model. However, the crutch with the damper system demonstrated a significantly larger peak propulsive force and impulse compared to both crutch models. This finding indicates that a forearm crutch with a damper system may help to propel the crutch forward when walking on level surfaces, which could impact forward momentum.

Mechanical efficiency of two commercial lever-propulsion mechanisms for manual wheelchair locomotion.

The purpose of this study was to (1) evaluate the mechanical efficiency (ME) of two commercially available lever-propulsion mechanisms for wheelchairs and (2) compare the ME of lever propulsion with hand rim propulsion within the same wheelchair. Of the two mechanisms, one contained a torsion spring while the other used a roller clutch design. We hypothesized that the torsion spring mechanism would increase the ME of propulsion due to a passive recovery stroke enabled by the mechanism. Ten nondisabled male participants with no prior manual wheeling experience performed submaximal exercise tests using both lever-propulsion mechanisms and hand rim propulsion on two different wheelchairs. Cardiopulmonary parameters including oxygen uptake (VO2), heart rate (HR), and energy expenditure (En) were determined. Total external power (Pext) was measured using a drag test protocol. ME was determined by the ratio of Pext to En. Results indicated no significant effect of lever-propulsion mechanism for all physiological measures tested. This suggests that the torsion spring did not result in a physiological benefit compared with the roller clutch mechanism. However, both lever-propulsion mechanisms showed decreased VO2 and HR and increased ME (as a function of slope) compared with hand rim propulsion (p < 0.001). This indicates that both lever-propulsion mechanisms tested are more mechanically efficient than conventional hand rim propulsion, especially when slopes are encountered.