Effects of carpal tunnel syndrome on force coordination and muscle coherence during precision pinch

Szu-Ching Lu, Kaihua Xiu, Ke Li, Tamara L Marquardt, Peter J Evans, Zong-Ming Li

Research output: Contribution to journalArticle

4 Citations (Scopus)
17 Downloads (Pure)

Abstract

Carpal tunnel syndrome (CTS), caused by entrapment of the median nerve in the carpal tunnel, impairs hand function including dexterous manipulation. The purpose of this study was to investigate the effects of CTS on force coordination and muscle coherence during low-intensity sustained precision pinch while the wrist assumed different postures. Twenty subjects (10 CTS patients and 10 asymptomatic controls) participated in this study. An instrumented pinch device was used to measure the thumb and index finger forces while simultaneously collecting surface electromyographic activities of the abductor pollicis brevis (APB) and first dorsal interosseous (FDI) muscles. Subjects performed a sustained precision pinch at 10% maximum pinch force for 15 sec with the wrist stabilized at 30° extension, neutral, or 30° flexion using customized splints. The force discrepancy and the force coordination angle between the thumb and index finger forces were calculated, as well as the β-band (15-30 Hz) coherence between APB and FDI. The index finger applied greater force than the thumb (p < 0.05); this force discrepancy was increased with wrist flexion (p < 0.05), but was not affected by CTS (p > 0.05). The directional force coordination was not significantly affected by wrist posture or CTS (p > 0.05). In general, digit force coordination during precision pinch seems to be sensitive to wrist flexion, but is not affected by CTS. The β-band muscular coherence was increased by wrist flexion for CTS patients (p < 0.05), which could be a compensatory mechanism for the flexion-induced exacerbation of CTS symptoms. This study demonstrates that wrist flexion negatively influences muscle and force coordination in CTS patients supporting the avoidance of flexion posture for symptom exacerbation and functional performance.

Original languageEnglish
Pages (from-to)328-335
Number of pages8
JournalJournal of Medical and Biological Engineering
Volume37
Issue number3
Early online date24 Mar 2017
DOIs
Publication statusPublished - 30 Jun 2017

Keywords

  • carpal tunnel syndrome
  • median nerve
  • precision pinch

Fingerprint Dive into the research topics of 'Effects of carpal tunnel syndrome on force coordination and muscle coherence during precision pinch'. Together they form a unique fingerprint.

  • Cite this