Impact of Surface Type, Wheelchair Weight, and Axle Position on Wheelchair Propulsion by Novice Older Adults

Abstract

Objective To examine the impact of surface type, wheelchair weight, and rear axle position on older adult propulsion biomechanics. Design Crossover trial. Setting Biomechanics laboratory. Participants Convenience sample of 53 ambulatory older adults with minimal wheelchair experience (65−87y); men = 20, women = 33. Intervention Participants propelled 4 different wheelchair configurations over 4 surfaces; tile, low carpet, high carpet, and an 8% grade ramp (surface, chair order randomized). Chair configurations included: (1) unweighted chair with an anterior axle position, (2) 9.05kg weighted chair with an anterior axle position, (3) unweighted chair with a posterior axle position (Δ0.08m), and (4) 9.05kg weighted chair with a posterior axle position (Δ0.08m). Weight was added to a titanium folding chair, simulating the weight difference between very light and depot wheelchairs. Instrumented wheels measured propulsion kinetics. Main Outcome Measures Average self-selected velocity, push-frequency, stroke length, peak resultant and tangential force. Results Velocity decreased as surface rolling resistance or chair weight increased. Peak resultant and tangential forces increased as chair weight increased, surface resistance increased, and with a posterior axle position. The effect of a posterior axle position was greater on high carpet and the ramp. The effect of weight was constant, but more easily observed on high carpet and ramp. The effects of axle position and weight were independent of one another. Conclusion Increased surface resistance decreases self-selected velocity and increases peak forces. Increased weight decreases self-selected velocity and increases forces. Anterior axle positions decrease forces, more so on high carpet. Effects of weight and axle position are independent. Greatest reductions in peak forces occur in lighter chairs with anterior axle positions.

Manual wheelchair satisfaction among long-term users and caregivers: A French study

“…Cowan et al concluded that the greatest reductions in the resultant peak force would be obtained with the lightest possible wheelchair [19]. To our knowledge, no studies have been carried out on satisfaction with wheelchair accessories.…”

“…affects self-selected velocity, peak resultant force, and peak tangential force and that the addition of 9 kg reduces self-selected velocity and increases peak forces on each surface [19]. Cowan et al concluded that the greatest reductions in the resultant peak force would be obtained with the lightest possible wheelchair [19].…”

Wheelchair users' perceived exertion during typical mobility activities

“…It has been reported that propulsion velocity decreases with an increase in rolling resistance. 20 That is likely to have been a factor in the relatively low self-selected speed of our participants.…”

A theoretical analysis of the influence of wheelchair seat position on upper extremity demand

“…contact angle, release angle) and temporal (i.e. push time, cadence) variables are influenced by propulsion technique and differences in upper extremity impairment (e.g., Newsam et al, 1996;Finley et al, 2004;Mulroy et al, 2004), training (e.g., Rodgers et al, 2001;Rice et al, 2010;Richter et al, 2011) and terrain (e.g., Newsam et al, 1996;Richter et al, 2007;Chow et al, 2009;Cowan et al, 2009). The wheelchair propulsion technique analyzed in this study was derived from representative spatiotemporal values (e.g., Richter, 2001;PVACSCM, 2005;Lin et al, 2009), but other techniques exist.…”