In this study, we investigated age differences in manual force production to explore their neurophysiological basis. Manual pinching and gripping forces were first measured during unilateral and bilateral efforts in two groups of right-handed adults (young, n = 12, senior, n = 11). Then, transcranial magnetic stimulation (TMS) was applied to each hemisphere to assess central motor inhibition via the contralateral and ipsilateral silent period (cSP, iSP). Laterality quotients (LQs) were computed to determine asymmetries for unimanual strength tests and hemispheric asymmetries in TMS measures. Bilateral indices (BLI) were computed to assess the bilateral force deficit (BFD). During unilateral efforts, both young and senior participants exhibited similar degrees of asymmetry. Similarly, no age difference was detected when comparing LQs derived from TMS measures. During bilateral efforts, although BLI tended to be lower in seniors, no age difference was detected. Asymmetry in strength and BLI showed no association with hemispheric asymmetry in TMS measures, except for the asymmetry in pinch strength, which was associated with asymmetry in the iSP duration. These observations confirm that asymmetries in manual strength and BFD are little affected by age. Also, our results show that hemispheric asymmetries in transcallosal inhibition are associated with pinch strength asymmetry.

在这项研究中，我们调查了人工力量产生的年龄差异，以探讨其神经生理学基础。首先在两组惯用右手的成年人（年轻，n  = 12，老人，n = 11）。然后，将经颅磁刺激（TMS）应用于每个半球，以通过对侧和同侧静默期（cSP，iSP）评估中枢运动抑制。计算横向商（LQ）以确定单手强度测试的不对称性和TMS度量中的半球不对称性。计算双边指数（BLI）以评估双边力量不足（BFD）。在单方面的努力中，年轻和资深参与者都表现出相似的不对称程度。同样，在比较由TMS测度得出的LQ时，未发现年龄差异。在双边努力中，尽管老年人的BLI倾向较低，但未发现年龄差异。强度和BLI的不对称性与TMS措施中的半球不对称性无关，除了捏合强度的不对称性，这与iSP持续时间的不对称有关。这些观察结果证实，人工力量和BFD的不对称性几乎不受年龄的影响。同样，我们的结果表明，经call骨抑制中的半球不对称与捏合强度不对称有关。