Effect of backpack load on nerve conduction velocity and risk of peripheral neuropathy in upper extremities of undergraduate medical students carrying backpack

Abstract

Background: Prolonged load carriage can potentially affect hand and upper limb use through compression of the nerves, reduction in blood flow, and muscle fatigue. Backpacks of undergraduate medical student are not much different from their syllabus. They carry heavy backpacks on regular basis and many times they wear it incorrectly. Aims and Objectives: We aimed to see the effect of backpack load on motor nerve conduction velocity and hand grip strength in the upper extremities. Materials and Methods: The present study included 31 undergraduate medical students between the age of 18 and 25 years. The procedure is conducted in three phases on different days. In each phase, participants were asked to walk for 5 min with load. In Phase 1, nerve conduction velocity and grip strength weere measured in unloaded condition and after carrying load <10% of body weight. To limit the effect of fatigue, participants are instructed to return to laboratory in next consecutive weeks to repeat the procedure for Phase 2 and 3 as in Phase 1 by increasing load to 10–20% and 20–30% of their body weight respectively. Results: Values of median and ulnar motor nerve conduction velocity obtained without and with increasing % of backpack load after 5 min walk were decreased non-significantly as load increased. There was significant (P>0.001) difference in grip strength of medical students carrying backpack with increasing load after 5 min walk. Conclusion: In this study, we aimed at quantifying the effects of load carriage on overall upper limb performance, with a focus on conduction velocity of motor nerves. This has implications for occupations such as soldiers, firefighters, paramedics, and others who may be required to operate machinery, equipment, tools, or systems that require precise motor control.