Arm Posture and Hand Mechanical Impedence in the Control of a Power Drill

This research investigated the control of a hand-held power drill by human operators. A better understanding of human performance in this context may be helpful for the automation of industrial processes, or to prevent occupational disorders such as Carpal Tunnel Syndrome or Hand-Arm Vibration Syndrome. We chose to investigate the control of a drill by analyzing the upper limb posture and hand stiffness of drill operators.

We found that posture was repeatable within a subject, that it was insensitive to both the level of axial force exerted and the drill length. In addition, posture was similar while drilling or pushing on the drill when turned off. These results suggest that upper limb kinematics is an important factor. However, neither maximization of hand manipulability nor isotropy characteristics of a 2D two link model could explain the posture selected by subjects. Instead, minimization of joint torques appeared plausible. Right handed subjects selected a posture that minimized shoulder torque, in contrast to left handed subjects who selected a posture that minimized elbow torque.

We have developed a model to demonstrate how hand stiffness can be used to compensate for the static instability induced by the axial force exerted on a drill handle. As hand stiffness could not be measured directly while subjects were drilling, it was measured while they were asked to push on a drill handle mounted on a pivoting stick. Results showed that subjects did more than simply compensate for the static instability; hand stiffness either remained constant or increased with force. We found no evidence that one would voluntarily modulate his/her hand stiffness to fulfill some criteria. Stiffness increase may just be a well-tuned side effect of muscle activation.

Year	Entry
1979	Amis AA, Dowson D, Wright V. Muscle strengths and musculoskeletal geometry of the upper limb. Eng Med. 1979;8(1):41.
1990	Winters JM, Woo SL-Y, eds. Multiple Muscle Systems: Biomechanics and Movement Organization. New York, NY: Springer-Verlag; 1990.
1982	Rodgers LA, Eglin D, Hart WFD. Rock-drill vibration and white fingers in miners. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:317-323.
1982	Suggs CW, Hanks JM. Resilient handgrips. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:333-337.
1982	Pyykkö I, Hyvärinen J, Färkkilä M. Studies on the etiological mechanism of the vasospastic component of the vibration syndrome. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:13-24.
1977	Reynolds DD, Keith RH. Hand-arm vibration, I: analytical model of the vibration response characteristics of the hand. J Sound Vibrat. March 22, 1977;51(2):237-253.
1982	Griffin MJ, Macfarlane CR, Norman CD. The transmission of vibration to the hand and the influence of gloves. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:103-116.
1982	Suggs CW, Hanks JM, Roberson GT. Vibration of power tool handles. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:245-251.
1982	Auerbach EI. An investigation of chipping hammer vibration. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:311-315.
1982	Azuma T, Ohhashi T. Pathophysiology of vibration-induced white finger: etiological considerations and proposals for prevention. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:31-38.
1990	Hogan N. Mechanical impedance of single- and multi-articular systems. In: Winters JM, Woo SL-Y, eds. Multiple Muscle Systems: Biomechanics and Movement Organization. New York, NY: Springer-Verlag; 1990:149-164.
1978	Chao EY, Morrey BF. Three-dimensional rotation of the elbow. J Biomech. 1978;11(1-2):57-73.
1990	Russell DL. An Analysis of Constrained Motions in Manipulation [PhD thesis]. Cambridge, MA: Massachusetts Institute of Technology; September 1990.
1984	Reynolds DD, Basel R, Wasserman DE, Taylor W. A study of hand vibration on chipping and grinding operators, III: power levels into the hands of operators of pneumatic tools used in chipping and grinding operations. J Sound Vibrat. August 22, 1984;95(4):515-524.
1990	Hogan N, Winters JM. Principles underlying movement organization: upper limb. In: Winters JM, Woo SL-Y, eds. Multiple Muscle Systems: Biomechanics and Movement Organization. New York, NY: Springer-Verlag; 1990:182-194.
1984	Reynolds DD, Falkenberg RJ. A study of hand vibration on chipping and grinding operators, II: four-degree-of-freedom lumped parameter model of the vibration response of the human hand. J Sound Vibrat. August 22, 1984;95(4):499-514.
1983	Grood ES, Suntay WJ. A joint coordinate system for the clinical description of three-dimensional motions: application to the knee. J Biomech Eng. May 1983;105(2):136-144.
1977	Reynolds DD, Angevine EN. Hand-arm vibration, II: vibration transmission characteristics of the hand and arm. J Sound Vibrat. March 22, 1977;51(2):255-265.
1982	Miwa T. Vibration-isolation systems for hand-held vibrating tools. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:303-310.

Year

Entry

1979

Amis AA, Dowson D, Wright V. Muscle strengths and musculoskeletal geometry of the upper limb. Eng Med. 1979;8(1):41.

1990

Winters JM, Woo SL-Y, eds. Multiple Muscle Systems: Biomechanics and Movement Organization. New York, NY: Springer-Verlag; 1990.

1982

Rodgers LA, Eglin D, Hart WFD. Rock-drill vibration and white fingers in miners. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:317-323.

1982

Suggs CW, Hanks JM. Resilient handgrips. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:333-337.

1982

Pyykkö I, Hyvärinen J, Färkkilä M. Studies on the etiological mechanism of the vasospastic component of the vibration syndrome. In: Brammer A., Taylor W, eds. Vibration Effects on the Hand and Arm in Industry. New York, NY: John Wiley & Sons; 1982:13-24.