Shoulder pain and jerk during recovery phase of manual wheelchair propulsion

Abstract

Repetitive loading of the upper limb due to wheelchair propulsion plays a leading role in the development of shoulder pain in manual wheelchair users (mWCUs). There has been minimal inquiry on understanding wheelchair propulsion kinematics from a human movement ergonomics perspective. This investigation employs an ergonomic metric, jerk, to characterize the recovery phase kinematics of two recommended manual wheelchair propulsion patterns: semi-circular and the double loop. Further it examines if jerk is related to shoulder pain in mWCUs. Data from 22 experienced adult mWCUs was analyzed for this study (semi-circular: n=12 (pain/without-pain:6/6); double-loop: n=10 (pain/without-pain:4/6)). Participants propelled their own wheelchair fitted with SMARTWheels on a roller dynamometer at 1.1 m/s for 3 min. Kinematic and kinetic data of the upper limbs were recorded. Three dimensional absolute jerk experienced at the shoulder, elbow and wrist joint during the recovery phase of wheelchair propulsion were computed. Two-way ANOVAs were conducted with the recovery pattern type and shoulder pain as between group factors. Findings: (1) Individuals using a semi-circular pattern experienced lower jerk at their arm joints than those using a double loop pattern (P<0.05, η²=0.32)_wrist;(P=0.05, η²=0.19)_elbow;(P<0.05, η²=0.34)_shoulder and (2) individuals with shoulder pain had lower peak jerk magnitude during the recovery phase (P≤0.05, η²=0.36)_wrist;(P≤0.05, η²=0.30)_elbow;(P≤0.05, η²=0.31)_shoulder. Conclusions: Jerk during wheelchair propulsion was able to distinguish between pattern types (semi-circular and double loop) and the presence of shoulder pain. Jerk provides novel insights into wheelchair propulsion kinematics and in the future it may be beneficial to incorporate jerk based metric into rehabilitation practice.

Introduction

Approximately 2 million Americans use a manual wheelchair for mobility (LaPlante and Kaye, 2010). Although the use of a manual wheelchair provides numerous benefits (Hosseini et al., 2012), the repetitive strain encountered by the upper limb during propulsion places significant demand on the tissues (Nichols et al., 1979, Gellman et al., 1988, Curtis et al., 1999, Finley et al., 2004) and has been implicated in upper limb injury (Cooper et al., 1998). Indeed up to 70% of manual wheelchair users (mWCUs) report upper extremity pain (Finley et al., 2004). Upper extremity injury in mWCUs has been linked to difficulty performing activities of daily living, decreased physical activity and decreased quality of life (Chow and Levy, 2011).

Consequently, wheelchair propulsion research has led to guidelines to minimize over-use injuries (Boninger et al., 2002, Koontz et al., 2002, Richter et al., 2007). In general the guidelines suggests that individuals use propulsion patterns such as semi-circular and double loop that maximizes the contact angle. However these guidelines do not discuss other kinematic markers of movement such as jerk, that has been implicated in overuse injuries (Berret et al., 2008, Cote et al., 2005, Mark and Landry, 2012, Srinivasan and Mathiassen, 2012, William and Zernicke, 2008).

Jerk, the third derivative of position has been widely employed in clinical rehabilitation and human motor control research to quantify movement smoothness and evaluate the performance of upper limb tasks (Hogan et al., 1987, Flash, 1990, Chang et al., 2005, Caimmi et al., 2008). Occupational ergonomics research has revealed distinct differences in arm jerk between movements in individuals with and without shoulder pain (Cote et al., 2005). Consequently, the purpose of this investigation is to examine jerk in wheelchair propulsion as a function of recovery pattern and shoulder pain.

To appreciate this research it is important that the reader understands that a typical push-rim wheelchair propulsion has two phases, a push phase (hands in contact with push-rim) and a recovery phase (hands move freely to initiate next push). Four general categories of recovery patterns widely reported in the literature are, semi-circular (SC), single loop (SLOP), double loop (DLOP) and ARC (Shimada et al., 1998, Boninger et al., 2002, Richter et al., 2007). The magnitude of forces and moments experienced by the shoulder joint during recovery phase of wheelchair propulsion can be high as that during the push phase (Mercer and Jennifer, 2006, Veeger et al., 1991; Rankin et al., 2011; Sosnoff et al., 2015). Given this association, it is logical to expect that shoulder pain will influence arm kinematics during the recovery phase of wheelchair propulsion. Indeed recent research shows that mWCUs with shoulder pain employed spatial adaptive strategies to wrist kinematics during the recovery phase of wheelchair propulsion (Jayaraman et al., 2014).

This analysis examines jerk-based metrics extracted from the three dimensional kinematics of the upper arm joints during wheelchair propulsion. The main goals are (1) to introduce and benchmark a jerk-based framework for wheelchair propulsion and (2) to examine jerk in wheelchair propulsion as a function of recovery pattern and shoulder pain. To accomplish these goals, two recovery pattern types, SC and DLOP patterns were analyzed. A DLOP pattern is characterized by the hands lifting over the propulsion path and crossing the propulsion path to drop below the hand-rim forming a double loop, while a SC pattern is characterized by the hands dropping below the hand-rim during the recovery phase (Sanderson and Sommer, 1985, Shimada et al., 1998, Boninger et al., 2002; Richter et al., 2007).

We postulate two hypotheses; (H1) that individuals using a SC recovery pattern will experience lower jerk magnitudes at their joints than individuals using a DLOP recovery pattern. (H2) that individuals with shoulder pain will minimize peak jerk magnitude at their upper arm joints during the recovery phase kinematics in an effort to avoid pain. H1 rests on the logical rationale that the arm’s movement trajectory during a SC pattern is simpler than a DLOP pattern. H2 is based on the observation that the neuromuscular system avoids large acceleration changes to avoid pain (Berret et al., 2008).