Wrist biomechanics during two speeds of wheelchair propulsion: An analysis using a local coordinate system

Department of Orthopaedic Surgery, University of Pittsburgh, PA, USA.
Archives of Physical Medicine and Rehabilitation (Impact Factor: 2.57). 04/1997; 78(4):364-72. DOI: 10.1016/S0003-9993(97)90227-6
Source: PubMed


To describe motion, forces, and moments occurring at the wrist in anatomic terms during wheelchair propulsion; to obtain variables that characterize wrist function during propulsion and are statistically stable; and to determine how these variables change with speed.
Case series.
Biomechanics laboratory.
Convenience sample of Paralympic athletes (n = 6) who use manual wheelchairs for mobility and have unimpaired arm function.
Subjects propelled a standard wheelchair on a dynamometer at 1.3m/sec and 2.2m/sec. Biomechanical data were obtained using a force and moment sensing pushrim and a motion analysis system.
Maximum angles, forces, and moments in a local, wrist coordinate system. Each variable was evaluated for stability using Cronbach's alpha. Measures found to be stable (infinity > .8) at each speed were then compared to look for differences associated with speed.
The following measures were stable at both speeds: maximum wrist flexion, ulnar deviation, and radial deviation angles, peak moments acting to cause wrist flexion, extension, and ulnar deviation, peak shear forces acting between the radial and ulnar styloids, and peak axial force acting at the wrist. Of these measures, the following measures differed (p < .05) between speeds (+/-SD): maximum radial deviation (1.3m/sec, 25.1 degrees +/- 9.0; 2.2m/sec, 21.4 degrees +/- 6.9), peak flexion moment (1.3m/ sec, 3.4N.m +/- 3.0; 2.2m/sec, 5.2N.m +/- 3.7), peak extension moment (1.3m/sec, 10.4N.m +/- 4.8; 2.2m/sec, 13.6N.m +/- 5.1), peak shear acting from the ulnar styloid to the radial styloid (1.3m/sec, 2.3N +/- 2.7, 2.2m/sec, 8.3N +/- 7.5) and maximum axial force (1.3m/sec, 50.9N +/- 18.2; 2.2m/sec, 65.9N +/- 27.6).
This study found stable parameters that characterize wrist biomechanics during wheelchair propulsion and varied with speed. Ultimately these parameters may provide insight into the cause and prevention of wrist injuries in manual wheelchair users.

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    • "Numerous studies using inverse dynamics analyses have documented high mechanical loads on the upper extremity (UE) during handrim wheelchair propulsion (Rodgers et al., 1994; Robertson et al., 1996; Boninger et al., 1997; Kulig et al., 1998; Boninger et al., 1999; Boninger et al., 2000; Boninger et al., 2002; Veeger et al., 2002a, b; Rozendaal and Veeger, 2003). While providing useful data and insights that can aid in determining potential links between propulsion mechanics and the development of pain, clinical interpretations made from intersegmental joint forces and moments calculated from an inverse dynamics model are limited. "
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    ABSTRACT: The primary purpose of this study was to compare static and dynamic optimization muscle force and work predictions during the push phase of wheelchair propulsion. A secondary purpose was to compare the differences in predicted shoulder and elbow kinetics and kinematics and handrim forces. The forward dynamics simulation minimized differences between simulated and experimental data (obtained from 10 manual wheelchair users) and muscle co-contraction. For direct comparison between models, the shoulder and elbow muscle moment arms and net joint moments from the dynamic optimization were used as inputs into the static optimization routine. RMS errors between model predictions were calculated to quantify model agreement. There was a wide range of individual muscle force agreement that spanned from poor (26.4% Fmax error in the middle deltoid) to good (6.4% Fmax error in the anterior deltoid) in the prime movers of the shoulder. The predicted muscle forces from the static optimization were sufficient to create the appropriate motion and joint moments at the shoulder for the push phase of wheelchair propulsion, but showed deviations in the elbow moment, pronation-supination motion and hand rim forces. These results suggest the static approach does not produce results similar enough to be a replacement for forward dynamics simulations, and care should be taken in choosing the appropriate method for a specific task and set of constraints. Dynamic optimization modeling approaches may be required for motions that are greatly influenced by muscle activation dynamics or that require significant co-contraction.
    Full-text · Article · Sep 2014 · Journal of Biomechanics
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    • "measuring the six components of the wrench (i.e. three forces: Fx, Fy, Fz, and three torques: Tx, Ty, Tz) applied by the user to the rear wheel handrim (Strauss et al. 1991, Asato et al. 1993, Rodgers et al. 1994, Rodgers et al. 1998, Dabonneville et al. 1998, Wu et al. 1998). These HRDs were mounted on different MWCs and used in several studies for calculating various dynamic or kinetic parameters during propulsion within a laboratory, either on a roller ergometer (Cooper et al. 1995, Cooper et al. 1996, Robertson et al. 1996, Cooper et al. 1997, Boninger et al. 1997, Rodgers et al. 1998) or directly on the floor (Strauss et al. 1991, Dabonneville et al. 1998, Vaslin et al., 1998, Wu et al. 1998, Dabonneville et al. 2000, Guo et al. 2003a, Dabonneville et al. 2005). "
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    ABSTRACT: A six-component handrim dynamometer (HRD) is a dynamometer that rotates around the wheel axle during measurements. For this kind of dynamometer, static zero level calibration is insufficient because the proportion of the forces (i.e. handrim weight and centrifugal force) measured by each sensor varies according to the angular position and velocity of the dynamometer. The dynamic calibration presented in this paper is based on the direct correction of the sensor signals using Fourier's polynomials that take into account the influences of both the handrim weight distribution on the sensors with respect to the wheel's angular position and the effect of the wheel's angular velocity. When these corrections were applied to the signals produced by the sensors while the HRD was rotating and no effort was being exerted on the handrim, the calculated forces and torques remained close to zero, as expected. Based on these results, the wheel dynamometer can be confidently used for studying manual wheelchair locomotion under various real conditions. The method could also be applied in other situations in which a dynamometer rotates during measurements.
    Full-text · Article · Mar 2014 · Computer Methods in Biomechanics and Biomedical Engineering
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    • "Therefore, decreasing of the start angle for the 15° camber decreases the radial deviation of the wrist, and an increase of the end angle increases the ulnar deviation of the wrist. The results are similar with the study of Boninger et al. in 1997 [35]. When the speed increased, wheelchair users' radial deviation angle significantly decreased. "
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    ABSTRACT: Background The rear-wheel camber, defined as the inclination of the rear wheels, is usually used in wheelchair sports, but it is becoming increasingly employed in daily propulsion. Although the rear-wheel camber can increase stability, it alters physiological performance during propulsion. The purpose of the study is to investigate the effects of rear-wheel cambers on temporal-spatial parameters, joint angles, and propulsion patterns. Methods Twelve inexperienced subjects (22.3±1.6 yr) participated in the study. None had musculoskeletal disorders in their upper extremities. An eight-camera motion capture system was used to collect the three-dimensional trajectory data of markers attached to the wheelchair-user system during propulsion. All participants propelled the same wheelchair, which had an instrumented wheel with cambers of 0°, 9°, and 15°, respectively, at an average velocity of 1 m/s. Results The results show that the rear-wheel camber significantly affects the average acceleration, maximum end angle, trunk movement, elbow joint movement, wrist joint movement, and propulsion pattern. The effects are especially significant between 0° and 15°. For a 15° camber, the average acceleration and joint peak angles significantly increased (p < 0.01). A single loop pattern (SLOP) was adopted by most of the subjects. Conclusions The rear-wheel camber affects propulsion patterns and joint range of motion. When choosing a wheelchair with camber adjustment, the increase of joint movements and the base of support should be taken into consideration.
    Full-text · Article · Nov 2012 · BioMedical Engineering OnLine
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