Effect of static wrist position on grip strength

Background: Grip strength after wrist arthrodesis is reported to be significantly less than normal. One of the reasons suggested for this decrease in grip strength is that the arthrodesis was performed in a suboptimal position. However, there is no consensus on the ideal position of wrist fusion. There is a paucity of studies evaluating the effect of various fixed positions of the wrist on grip strength and therefore, there is no guide regarding the ideal position of wrist fusion. The authors′ aim was to determine the grip strength in various fixed positions of the wrist and subsequently to find out in which position of wrist fusion the grip strength would be maximal.
Materials and Methods: One hundred healthy adults participated in the study. For the purpose of this study, the authors constructed splints to hold the wrist in five different fixed positions: 45, 30 and 15 degrees of wrist extension, neutral and 30 degrees of wrist flexion. The grip strength in all the participants was measured bilaterally, first without a splint and then with each splint sequentially.
Results: The average grip strength without the splint was 34.3 kg for right and 32.3 kg for the left hand. Grip strength decreased by 19-25% when the wrist was splinted. The maximum average grip strength with a splint on was recorded at 45 degrees of extension (27.9 kg for right and 26.3 kg for left side). There was a gradual increase in the grip strength with increase in wrist extension but the difference was not statistically significant (P = 0.29). The grip strength was significantly less in flexed position of the wrist (P < 0.001).