Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan.
Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan.
Physiol Rep. 2021 Aug;9(15):e14981. doi: 10.14814/phy2.14981.
A shorter joint moment arm (MA) may help maintain the necessary muscle force when muscle contractions are repeated. This beneficial effect may contribute to reducing the energy cost during running. In this study, we examined the correlation between patellar tendon MA and running performance in endurance runners. The patellar tendon MA and quadriceps femoris muscle volume (MV) in 42 male endurance runners and 14 body size-matched male untrained participants were measured using a 1.5-T magnetic resonance system. The patellar tendon MA was significantly shorter in endurance runners than in untrained participants (p = 0.034, d = 0.65). In endurance runners, shorter patellar tendon MA correlated significantly with better personal best 5000-m race rime (r = 0.322, p = 0.034). A trend toward such a significant correlation was obtained between quadriceps femoris MV and personal best 5000-m race time (r = 0.303, p = 0.051). Although the correlation between patellar tendon MA and personal best 5000-m race time did not remain significant after adjusting for the quadriceps femoris MV (partial r = 0.247, p = 0.120), a stepwise multiple regression analysis (conducted with body height, body mass, patellar tendon MA, and quadriceps femoris MV) selected the patellar tendon MA (β = 0.322) as only a predictive variable for the personal best 5000-m race time (adjusted R = 0.081, p = 0.038). These findings suggest that the shorter patellar tendon MA, partially accorded with the smaller quadriceps femoris size, may be a favorable morphological variable for better running performance in endurance runners.
较短的关节力臂（MA）可能有助于在肌肉收缩重复时保持必要的肌肉力量。这种有益的效果可能有助于降低跑步时的能量消耗。在这项研究中，我们检查了髌腱 MA 与耐力跑者跑步表现之间的相关性。使用 1.5-T 磁共振系统测量了 42 名男性耐力跑者和 14 名身体尺寸匹配的未训练男性参与者的髌腱 MA 和股四头肌肌肉量（MV）。与未训练的参与者相比，耐力跑者的髌腱 MA 明显更短（p=0.034，d=0.65）。在耐力跑者中，较短的髌腱 MA 与个人最佳 5000 米比赛时间呈显著相关（r=0.322，p=0.034）。股四头肌 MV 与个人最佳 5000 米比赛时间之间也存在这种显著相关性的趋势（r=0.303，p=0.051）。尽管在调整股四头肌 MV 后，髌腱 MA 与个人最佳 5000 米比赛时间的相关性不再显著（偏相关 r=0.247，p=0.120），但逐步多元回归分析（以身高、体重、髌腱 MA 和股四头肌 MV 为自变量）仅选择髌腱 MA（β=0.322）作为个人最佳 5000 米比赛时间的预测变量（调整后的 R ²=0.081，p=0.038）。这些发现表明，较短的髌腱 MA 部分与较小的股四头肌大小相吻合，可能是耐力跑者更好跑步表现的有利形态学变量。
