Motor unit number index examination in dominant and non-dominant hand muscles. Laterality 2015;20(6):699-710
Date
08/01/2015Pubmed ID
26227495Pubmed Central ID
PMC4549196DOI
10.1080/1357650X.2015.1041971Scopus ID
2-s2.0-84940460093 (requires institutional sign-in at Scopus site) 7 CitationsAbstract
This study investigated the effect of handedness on motor unit number index (MUNIX). Maximal hand strength, compound muscle action potential (CMAP) and voluntary surface electromyography (EMG) signals were measured bilaterally for the first dorsal interosseous (FDI) and thenar muscles in 24 right-handed and 2 left-handed healthy subjects. Mean (±standard error) grip and pinch forces in the dominant hand were 43.99 ± 2.36 kg and 9.36 ± 0.52 kg respectively, significantly larger than those in the non-dominant hand (grip: 41.37 ± 2.29 kg, p < .001; pinch: 8.79 ± 0.46 kg, p < .01). Examination of myoelectric parameters did not show a significant difference among the CMAP area, the MUNIX or motor unit size index (MUSIX) between the two sides in the FDI and thenar muscles. In addition, there was a lack of correlation between the strength and myoelectric parameters in regression analysis. However, strong correlations were observed between dominant and non-dominant hand muscles in both strength and myoelectric measures. Our results indicate that the population of motor units or spinal motor neurons as estimated from MUNIX may not be associated with handedness. Such findings help understand and interpret the MUNIX during its application for clinical or laboratory investigations.
Author List
Li X, He W, Li C, Wang YC, Slavens BA, Zhou PAuthors
Xiaoyan Li PhD Assistant Professor in the Neurology department at Medical College of WisconsinBrooke Slavens BS,MS,PhD Professor in the Mechanical Engineering department at University of Wisconsin - Milwaukee
MESH terms used to index this publication - Major topics in bold
AdultElectromyography
Female
Functional Laterality
Hand
Hand Strength
Humans
Male
Middle Aged
Muscle Contraction
Muscle, Skeletal
Regression Analysis
Signal Processing, Computer-Assisted
Young Adult
