Description

Background and Objectives: Falls are a serious public health issue among older adults and using assistive equipment may lead to increased safety in the home. The Step2Bed (S2B) is an adjustable step stool with a handrail that can be used to increase safety during bed entry and exit. The purpose of this study was to compare bed entry and exit time, muscle activation, joint angles, and ground reaction forces (GRF) of older adults with and without the use of the S2B. We hypothesized that using the S2B during bed transfers would result in decreased transfer times, GRF, co-contraction, required range of motion and movement variability when compared to without the S2B. Methods: Thirty-five participants (mean age=70.9) transferred on and off a plinth under three conditions: using the S2B with handrail (S2B+H), using the S2B without handrail (S2B-H), and without using the S2B (control). Each condition was repeated 3 times and trial order was randomized. Trials were video-recorded to calculate ingress and egress durations. GRF were collected via force plates, electromyography collected muscle activity and joint angles through electro-goniometers. A repeated-measures ANOVA was used to compare these outcomes across conditions. Results: Egress time was significantly less while using the S2B+H (2.1s) compared to control (2.9s) (p<.001). Ingress time was lowest with S2B+H, but not significantly. S2B+H and S2B-H trials resulted in smaller shear forces and vertical forces compared to control (all p<0.026). Center of pressure excursion and displacement in anterior-posterior and medio-lateral directions were lowest in S2B+H, but not significantly. Knee range of motion, angle velocity and variability were significantly less during S2B+H compared to control (all p<0.003). Co-contraction between the plantarflexors and dorsiflexors was lowest when using the S2B+H in comparison to control (all p<0.043). Conclusions: Lower range of motion and GRF while using the S2B+H suggests that it helped to decrease the effort required during bed egress compared to control. Decreased transfer duration, movement variability and co-contraction while using the S2B+H suggests that it provides stability and increased safety while transferring out of bed.