Preliminary feasibility and acute physiological effects of a single session of upper limb vibration training for persons with spinal cord injury.

CONTEXT: Strong upper limb musculature is essential for persons with spinal cord injury (SCI) to operate a manual wheelchair and live independently. Targeted upper limb vibration may be a viable exercise modality to build muscle efficiently while eliminating some of the barriers associated with exercise for persons with SCI. OBJECTIVE: The purpose of this study was to assess preliminary feasibility of completing a single exercise session of upper limb vibration and compare the acute physiological effects to a single session of standard dumbbell resistance exercise. METHODS: Individuals with SCI performed seven upper limb exercises (1) isometrically using a vibrating dumbbell at 30 Hz for 60 s (n = 22) and (2) using a standard isotonic resistance protocol (n = 15). RESULTS: Nineteen (86.4%) of 22 participants were able to perform all vibration exercises at 30 Hz but hold time success rates varied from 33% (side flies and front raises) to 95% (internal rotation). No significant differences were found between vibration exercise and standard resistance protocol for blood lactate, power output, and heart rate (P > 0.05). Perceptions of the training were positive, with most participants (>70%) expressing interest to train with vibration in the future. CONCLUSIONS: Vibration training was not feasible for all participants, suggesting an individualized approach to starting weight and progression may be necessary. Similar acute physiological changes were seen between vibration exercise and standard resistance protocol, suggesting they could have similar benefits. Additional research is needed to determine if vibration exercise is feasible and beneficial to incorporate into a long-term training program.

Toward Developing a Powered Ankle-Foot Prosthesis With Electromyographic Control to Enhance Functional Performance: A Case Study in a U.S. Service Member.

The only commercially available ankle-foot prosthesis with powered propulsion lacks ruggedization and other capabilities for service members seeking to return to duty and/or other physically demanding activities. Here, we evaluated a ruggedized powered ankle-foot prosthesis with electromyographic control ("Warrior Ankle"; WA) in an experienced male user of the predicate (Empower) prosthesis. The participant (age = 56 years, mass = 86.8 kg, stature = 173 cm) completed a 650 m simulated hike with varying terrain at a fixed, self-selected speed in the WA and predicate prosthesis, with and without a 22.8 kg weighted vest ("loaded" and "unloaded," respectively). Peak dorsiflexion and plantarflexion angles were extracted from each gait cycle throughout the simulated hike (∼500 prosthetic-side steps). The participant walked faster with the WA (1.15 m/s) compared to predicate (0.80 m/s) prosthesis. On the prosthetic side, peak dorsiflexion angles were larger for the WA (loaded: 27.9°; unloaded: 26.9°) compared to the predicate (loaded: 19.4°; unloaded: 21.3°); peak plantarflexion angles were similar between prostheses and loading conditions [WA (loaded: 15.5°; unloaded: 14.9°), predicate (loaded: 16.9°; unloaded: 14.8°). The WA better accommodated the varying terrain profile, evidenced by greater peak dorsiflexion angles, as well as dorsiflexion and plantarflexion angles that more closely matched or exceeded those of the innate ankle [dorsiflexion (WA: 31.6°, predicate: 27.5°); plantarflexion (WA: 20.7°, predicate: 20.5°)]. Furthermore, the WA facilitated a faster walking speed, suggesting a greater functional capacity with the WA prosthesis. Although further design enhancements are needed, this case study demonstrated feasibility of a proof-of-concept, ruggedized powered ankle-foot prosthesis with electromyographic control.

Accessibility facilitators and barriers affecting independent wheelchair transfers in the community.

PURPOSE: The purpose of this study is to identify facilitators and barriers to wheelchair transfers in the community and to identify specific places and surfaces in the community where increasing transfer accessibility could enable greater participation. METHODS: This study enrolled 112 wheeled mobility device users who completed a survey describing barriers to independent transfers. Descriptive statistics (means, standard deviations, and percentages) were used to report the survey results. RESULTS: The majority of subjects (≥50% of the sample) who were impacted by the following features found them to be helpful while transferring: presence of transfer aids, presence of grab bars, large enough transfer surface size, storage space for a wheeled mobility device (WMD), large amounts of space and clearance for legs and feet, soft surfaces, and enough space next to the transfer surface. Ninety percent (90.5%) felt their participation was limited when surfaces higher than their WMD were encountered. Participants also reported feeling limited in their participation due to lack of transfer accessibility at a variety of community destinations, including medical facilities (35.1%), modes of transportation (38.5-52.1%), pools and hot tubs (45.4%), dressing rooms (50.0%), amusement parks (49.1%), and boating areas (52.1%). CONCLUSION: Improving accessibility for independent transfers in the community may support greater participation and lead to a better quality of life. Study findings provide insight into changes that would make the built environment more accessible and safer for wheelchair users who independently transfer.Implications for rehabilitationTransferring independently is one of the most physically demanding tasks for wheelchair users, and physical and environmental factors may affect transferability in the community.Identifying environmental facilitators and barriers to transfers may improve accessibility for wheelchair users, allowing for greater community participation, reduced risk of falls and injuries, and improvements to quality of life.

Rehabilitation professional and user evaluation of an integrated push-pull lever drive system for wheelchair mobility.

Wheeled mobility devices enable persons with limited mobility to maintain an independent lifestyle. Lever-drive propulsion options have been shown to increase wheeled mobility device efficiency while reducing physical strain on users. Despite these benefits, they have not been widely adopted for everyday use. Two novel lever-drive devices (RoScooter and RoTrike) provide an alternative to pushrim propulsion by using an integrated front-and-center push-pull lever mechanism. The objectives of this study were to assess the usability and performance of the lever-drive devices using both rehabilitation professional and user feedback. The study enrolled 17 rehabilitation professionals and 13 users who performed various mobility tasks to rate the performance of the RoScooter and RoTrike for ease of use, stability, safety, appearance, and comfort. Users were graded on their performance using a scoring system based on the Wheelchair Skills Test. Rehabilitation professionals suggested improvements in regard to adjustability, maneuverability, target population, and appearance, preferring the operations of the RoScooter to the RoTrike. Users reported that the devices were entertaining and easy to use, but improvements in adjustability, reversal methods, and operation options to appeal to a wider range of consumers are needed before lever-drive devices are suitable to replace or supplement current wheeled mobility devices.

An ergonomic comparison of three different patient transport chairs in a simulated hospital environment.

The purpose of this study was to compare caregiver muscle activation and joint angles between two ergonomic transport chairs designed to mitigate discomfort and safety risks associated with patient transport, the Stryker® Prime TC and the Staxi® Medical Chair, and a depot wheelchair. Twenty-three caregivers completed level walking and ramped tasks with each device and an 84 kg manikin. Surface electromyography for the upper extremities and back muscles and motion data were collected. The Staxi showed a statistical trend for higher wrist extensor and flexor carpi ulnaris activity compared to the Stryker chair (p ≤ 0.078) and greater wrist flexion than the Stryker and depot chairs (p ≤ 0.004). The depot chair showed greater peak trunk flexion than the Stryker chair (p = 0.004). Overall results suggest that ergonomic chair design may improve joint positioning of the trunk and elbows when operating patient transport chairs over level and ramped surfaces.

Upper-limb biomechanical analysis of wheelchair transfer techniques in two toilet configurations.

BACKGROUND: Using proper technique is important for minimizing upper limb kinetics during wheelchair transfers. The objective of the study was to 1) evaluate the transfer techniques used during toilet transfers and 2) determine the impact of technique on upper limb joint loading for two different toilet configurations. METHODS: Twenty-six manual wheelchair users (23 men and 3 women) performed transfers in a side and front wheelchair-toilet orientation while their habitual transfer techniques were evaluated using the Transfer Assessment Instrument. A motion analysis system and force sensors were used to record biomechanical data during the transfers. FINDINGS: More than 20% of the participants failed to complete five transfer skills in the side setup compared to three skills in the front setup. Higher quality skills overall were associated with lower peak forces and moments in both toilet configurations (-0.68 < r < -0.40, p < 0.05). In the side setup, participants who properly placed their hands in a stable position and used proper leading handgrips had lower shoulder resultant joint forces and moments than participants who did not perform these skills correctly (p ≤ 0.04). In the front setup, positioning the wheelchair within three inches of the transfer target was associated with reduced peak trailing forces and moments across all three upper limb joints (p = 0.02). INTERPRETATION: Transfer skills training, making toilet seats level with the wheelchair seat, positioning the wheelchair closer to the toilet and mounting grab bars in a more ideal location for persons who do sitting pivot transfers may facilitate better quality toilet transfers.