Original Research Article
Year: 2018 | Month: January-March | Volume: 3 | Issue: 1 | Pages: 7-12
Nerve Conduction Studies and Surface Electromyography in Barbers
Dr. Priza Subedi1, Dr. Dilip Thakur2, Dr. Rita Khadka2, Dr. Bishnu Hari Poudel3
1Assistant Professor, 2Additional Professor, Basic and Clinical Physiology, 3Professor, B.P Koirala Institute of Health Sciences, Dharan, Nepal
Corresponding Author: Dr. Priza Subedi
Background: Prolonged standing can have deleterious effects on the muscles and peripheral nerves of lower limbs leading to peripheral neuropathy. Barbers stand for quite a long period as due to their occupation which can expose them to neuromuscular disorders.
Aims: To study nerve conduction and surface electromyography of lower limbs; and psychological fatigue in barbers.
Material and methods: This cross sectional study included 26 barbers and 30 healthy controls. Anthropometric, nerve conduction and surface EMG variables were recorded in both groups. Compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) of peripheral nerves of both limbs and motor unit action potentials (MUAPs) of gastrocnemius muscles were recorded. Psychological fatigue was assessed using the Borg scale in the barbers. The unpaired “t” test was applied for comparing anthropometric, cardio respiratory, nerve conduction and surface EMG variables between barbers and controls. Pearson’s correlation was applied for finding association between fatigue score and surface EMG variables in barbers.
Results: CMAP and SNAP responses of peripheral nerves of lower limbs were low in barbers as compared to controls (p <0.05). MUAPs amplitude of left gastrocnemius muscles on activity and recruitment and also, amplitude of right gastrocnemius muscle on activity were high in barbers as compared to controls (p<0.05). Frequency of MUAPs of both gastrocnemius muscles on recruitment positively correlated with fatigue score in the barbers.
Conclusion: The decrease in CMAP and SNAP amplitudes of peripheral nerves in barbers might be due to repetitive stress in the form of prolonged standing leading to entrapment neuropathies. Surface EMG findings showing an increase in MUAP amplitude of both gastrocnemius muscles are an indication of muscle fatigue.
Keywords: muscle fatigue; prolonged standing