This study investigated changes in median nerve conduction velocity (NCV) over several weeks of exposure to a voluntary, moderately forceful, repetitive pinching task performed for food rewards by a small sample of young adult female monkeys (Macaca fascicularis). Sensory NCV, derived from peak latency, decreased significantly in the working hands of three of the four subjects. The overall decline in NCV was 25–31% from baseline. There was no decrease in NCV in the non-working hands. The results demonstrate a temporally unambiguous relationship between exposure to a moderately forceful, repetitive manual task and development of median mononeuropathy. This study contributes to the pattern of evidence of a causal relationship between manual work and significant median nerve impairment (carpal tunnel syndrome in humans). In the future, such a model could be used to assess dose-response relationships between physical risk factors and carpal tunnel syndrome.
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References
1.
ArmstrongTJCastelliWAEvansFGDiaz-PerezR. (1984). Some histological changes in carpal tunnel contents and their biomechanical implications. J Occup Med, 26(3), 197–201.
2.
ArmstrongTJChaffinDB (1979). Some biomechanical aspects of the carpal tunnel. J Biomech, 12(7), 567–570.
3.
BanksJJLavenderSABufordJASommerichCM (2006). Measuring palmer pinch strength in non-human primates: Macaca Fascicularis. Paper presented at the 52nd Annual Meeting of Orthopaedic Research Society.
4.
BarrAEBarbeMF (2002). Pathophysiological tissue changes associated with repetitive movement: A review of the evidence. Phys Ther, 82(2), 173–187.
5.
BernardBP (1997). Musculoskeletal Disorders and Workplace Factors (No. DHHS (NIOSH) Publication No. 97–141): US Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health.
6.
ChengEJScottSH (2000). Morphometry of Macaca mulatto forelimb. I. Shoulder and elbow muscles and segment inertial parameters. J Morph, 245, 206–224.
7.
ClarkBDAl-ShattiTABarrAEAminMBarbeMF (2004). Performance of a high-repetition, high-force task induces carpal tunnel syndrome in rats. J Orthop Sports Phys Ther, 34(5), 244–253.
8.
ClarkBDBarrAESafadiFFBeitmanLAl-ShattiTAminM (2003). Median nerve trauma in a rat model of work-related musculoskeletal disorder. J Neurotrauma, 20(7), 681–695.
9.
FalkinerSMyersS. (2002). When exactly can carpal tunnel syndrome be considered work-related?ANZ J Surg, 72(3), 204–209.
10.
GoldsteinSAArmstrongTJChaffinDBMatthewsLS (1987). Analysis of cumulative strain in tendons and tendon sheaths. J. Biomech, 20(1), 1–6.
11.
HakimAJCherkasLEl ZayatSMacGregorAJSpectorTD (2002). The genetic contribution to carpal tunnel syndrome in women: A twin study. Arthritis Rheum, 47(3), 275–279.
12.
HowellABStrausWL (1933). The muscular system. In HartmanCCStrausWL (Eds.), The Anatomy of the Rhesus Monkey (Macaca mulatto) (pp. 67–175). New York: Hafner.
13.
KeirPBachJMRempelD. (1998a). Fingertip loading and carpal tunnel pressure: Differences between a pinching and a pressing task. J Orthop Res, 16(1), 112–115.
14.
KeirPWellsRPLaveryW. (1997). The effects of tendon load and posture on carpal tunnel pressure. J Hand Surg [Am], 22(4), 628–634.
15.
KeirPJBachJMRempelDM (1998b). Effects of finger posture on carpal tunnel pressure during wrist motion. J Hand Surg [Am], 23(6), 1004–1009.
16.
LiuJLauHKPereiraBPKumarVPPhoRW (1996). Terminal nerve branch entries (motor points) of forearm muscles: A comparative study between monkey and human. Acta Anat (Basel), 155(1), 41–49.
17.
MackinnonSEDellonAL (1988). Evaluation of microsurgical internal neurolysis in a primate median nerve model of chronic nerve compression. J Hand Surg [Am], 13(3), 345–351.
18.
MackinnonSEDellonALHudsonARHunterDA (1985). A primate model for chronic nerve compression. J Reconstr Microsurg, 1(3), 185–195.
19.
MooreJSGargA. (1995). The Strain Index: A proposed method to analyze jobs for risk of distal upper extremity disorders. Am Ind Hyg Assoc J, 56(5), 443–458.
20.
NapierJR (1960). Studies of the hands of living primates. Proc Zoo Soc Lond, 133, 647–657.
21.
NapierJR (1961). Prehensibility and opposability in the hands of primates. Symposium Zoo Soc Lond, 5, 115–132.
22.
NapierJR (1993). Hands. Princeton: Princeton University Press.
RoquelaureYMechaliSDanoCFanelloSBenettiFBureauD (1997). Occupational and personal risk factors for carpal tunnel syndrome in industrial workers. Scand J Work Environ Health, 23(5), 364–369.
25.
RydevikBLundborgGBaggeU. (1981). Effects of graded compression on intraneural blood flow. J Hand Surg, 6(1), 3–12.
26.
SchuindFVenturaMPasteelsJL (2090). Idiopathic carpal tunnel syndrome: Histologic study of flexor tendon synovium. J Hand Surg [Am], 15(3), 497–503.
27.
SzaboRMGelbermanRH (1987). The pathophysiology of nerve entrapment syndromes. J Hand Surg, 12A(5, part 2), 880–884.
28.
TichauerER (1978). The biomechanical basis of ergonomics. New York: Wiley-Interscience.
29.
Viikari-JunturaESilversteinB. (1999). Role of physical load factors in carpal tunnel syndrome. Scand J Work Environ Health, 25(3), 163–185.
