The Relationships Between Muscle Weakness, Wheelchair Propulsion Technique and Upper Extremity Demand

Links

Abstract

There are millions of individuals throughout the world that rely on manual wheelchair propulsion as their primary method of mobility. Due to the considerable physical demand of wheelchair propulsion, these individuals are at an increased risk of developing upper extremity pain and injuries that can lead to a progressive decline in independence and quality of life. The overall goal of this research was to use a combination of experimental analyses and forward dynamics simulation techniques to gain an increased understanding of the relationships between muscle weakness, wheelchair propulsion technique and upper extremity demand.

In the first study, a set of simulations was used to investigate the compensatory mechanisms that result from weakness in specific muscle groups. The simulation results suggested that the upper extremity musculature is robust to weakness in individual muscle groups as other muscles were able to compensate and restore normal propulsion mechanics. However, high stress levels and potentially harmful shifts in power generated by the rotator cuff muscles were observed. Such overuse could lead to the development of pain and injury in these muscles, suggesting that rehabilitation programs should target strengthening these muscles.

In the second study, a set of objective quantitative parameters was developed to characterize kinematic hand patterns and assess the influence of propulsion speed and grade of incline on the patterns preferred by a group of 170 experienced manual wheelchair users. Increased propulsion speed resulted in a shift away from under-rim hand patterns while increased grade resulted in the hand remaining near the handrim throughout the propulsion cycle. These results identified how individuals modify their hand patterns in response to different propulsion conditions encountered in daily activities.

In the third study, simulations of four commonly observed hand pattern types were generated. The simulations revealed the double loop and semi-circular patterns had the lowest overall muscle stress and total muscle power, suggesting that these hand patterns may reduce upper extremity demand. Together, the results of these studies have provided a scientific basis for designing rehabilitation and training programs aimed at reducing the prevalence of upper extremity injury and pain among individuals who use manual wheelchairs.

Cited Works (11)

Year	Entry
2006	Liu MQ, Anderson FC, Pandy MG, Delp SL. Muscles that support the body also modulate forward progression during walking. J Biomech. 2006;39(14):2623-2630.
2007	Erdemir A, McLean S, Herzog W, van den Bogert AJ. Model-based estimation of muscle forces exerted during movements. Clin Biomech (Bristol, Avon). February 2007;22(2):131-154.
1997	Raasch CC, Zajac FE, Ma B, Levine WS. Muscle coordination of maximum-speed pedaling. J Biomech. June 1997;30(6):595-602.
2002	Zajac FE, Neptune RR, Kautz SA. Biomechanics and muscle coordination of human walking, I: introduction to concepts, power transfer, dynamics and simulations. Gait Post. December 2002;16(3):215-232.
1988	Winters JM, Stark L. Estimated mechanical properties of synergistic muscles involved in movements of a variety of human joints. J Biomech. 1988;21(12):1027-1041.
2005	Holzbaur KRS, Murray WM, Delp SL. A model of the upper extremity for simulating musculoskeletal surgery and analyzing neuromuscular control. Ann Biomed Eng. June 2005;33(6):829-840.
2010	Hamner SR, Seth A, Delp SL. Muscle contributions to propulsion and support during running. J Biomech. October 19, 2010;43(14):2709-2716.
1987	Davy DT, Audu ML. A dynamic optimization technique for predicting muscle forces in the swing phase of gait. J Biomech. 1987;20(2):187-201.
1994	Goffe WL, Ferrier GD, Rogers J. Global optimization of statistical functions with simulated annealing. J Econom. January–February 1994;60:65-99.
2001	de Groot JH, Brand R. A three-dimensional regression model of the shoulder rhythm. Clin Biomech (Bristol, Avon). November 2001;16(9):735-743.
2001	Neptune RR, Kautz SA, Zajac FE. Contributions of the individual ankle plantar flexors to support, forward progression and swing initiation during walking. J Biomech. November 2001;34(11):1387-1398.