Is there a correlation between the grip strength and the intrinsic muscles/intermetacarpal spaces of the hand?: An ultrasonographic study

Purpose: Gripping is a unique human ability and an extremely complicated action. The aim of this study is to investigate the correlation of the grip strength with sonographic measurement of intrinsic muscles (IM) and the intermetacarpal spaces (IMS) of the hand.

Materials and methods: A total of 38 healthy volunteers (mean age:39.4 years) were examined. All the patients were first evaluated by a physiatrist to rule out any pathology involving the hand. Grip strength was assessed by JAMAR hand dynamometer. Afterwards, IM and IMS areas for both hands (n:76) were measured sonographically at three levels (2nd,3rd and 4th intermetacarpal; palmar side for IM, dorsal side for IMS) by the same radiologist. Pearson's correlation test was used for statistical analysis

Results: The mean grip strength was 41.2±12.4 pounds (range: 20–67.5). Mean areas for IM were 0.91±0.17mm², 0.72±0.14mm², 0.80±0.12mm², and mean areas for IMS were 0.53±0.11mm², 0.46±0.09mm² and 0.42±0.09mm² at 2nd, 3rd and 4th intermetacarpal levels, respectively. There was a positive correlation between the grip strength and the area of IM and IMS (p<0,05 r: 0,259–0,409).

Conclusion: To our knowledge, this is the first study evaluating the correlation of grip strength and the sonographic IM-IMS measurements. The IM and IMS have an important mechanical contribution in the grip strength. This may be of major concern in the diagnosis and follow-up of a variety of clinical conditions. Further research in study groups affected by clinical situations involving the hand, is necessary to reveal the role of IM and IMS