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Introduction. Several studies have quantified the benefit of using. Pushrim-Activated Power-Assisted Wheelchairs. (PAPAW) to assist manual wheelchair (MW) ...
EFFECT OF A POWER-ASSISTED MANUAL WHEELCHAIR ON THE BIOMECHANICAL PARAMETERS OF THE PROPULSION CYCLE. Didier Pradon (1), Elodie Garrec (1), Isabelle Vaugier (2), Thierry Weissland (3), Caroline Hugeron (4), Bruno Guillon (5) 1. U1179 End:icap CHU Raymond Poincaré UVSQ, France; 2. CIC 1429 CHU Raymond Poincaré UVSQ, France; 3. EA-3300, UFR-STAPS UPJV, France, 4. CHU Raymond Poincaré UVSQ, France, 5. Fondation Garches, France

Introduction

Results

Several studies have quantified the benefit of using Pushrim-Activated Power-Assisted Wheelchairs (PAPAW) to assist manual wheelchair (MW) users in their daily movement [1,2]. These studies highlight the efficiency of these PAPAW in increasing the movement autonomy. However, few studies focused on the biomechanical or physiological parameters of the MW propulsion when users used these PAPAW. According to the systematic review of Kloosterman et al. [3] from 2013 completed with a pubmed research based on the same keywords, only 9 studies in total stand out. Yet recent epidemiological studies by Florio et al. [4] emphasized the interest in specifically exploring the use of mobility assistance such as PAPAW. In recent years PAPAW have improved. New technological solutions have been proposed to such as adding a fifth motorized wheel instead of replacing the rear wheels. The purpose of this study is to evaluate the effect of the use of the SmartDrive on the biomechanical parameters of the MW propulsion cycle.

The main results show significant differences in all analyzed parameters. The use of the SmartDrive (SD) reduces the effort during the propulsion of the MW : total and tangential forces, as well as the external mechanical power. The Use of the SD increases the traveled distance during the 6 minutes test. In fact, the patients with SD travel 538 ± 104m and the ones without SD only 470 ± 124m.

Methods 22 spinal cord injury subjects were recruited (47±11 years old; 1.75±0.08m; 69±13kg) and signed an informed consent. All subjects used their personal MW. An instrumented wheel (SmartWheel, Out-Front; Mesa, Arizona, USA) was used to collect kinetic data. The push rim kinetic data, during the propulsion, were collected at 240 Hz. A motorized wheel (SmartDrive MX2, Max Mobility, Antioch, TN, USA) was used. This propulsion assistance is activated when the subject realizes a first propulsion. The engine develops a torque that moves the wheelchair without the subject participation. The travel in MW was performed on an outdoor path with an outdoor smooth tar coated path. The Subjects were asked to move at their favorite speed during a 6 minutes test. Each subject makes several round trip on a 150m straight line formed half by a 3% slope and a flat part. The analyzed variables were: distance and speed over the total duration of the test. Concerning the kinetic parameters, the following parameters were quantified over the first 150 meters: power, number of cycle, total force, tangential force, average speed. A Wilcoxon test was used with a significativity when p