Vaisman Alex, Guiloff Rodrigo, Rojas Juan, Delgado Iris, Figueroa David, Calvo Rafael
Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile.
Orthop J Sports Med. 2017 Dec 21;5(12):2325967117744240. doi: 10.1177/2325967117744240. eCollection 2017 Dec.
Achieving a symmetrical power performance (difference <15%) between lower limbs is generally recommended during sports rehabilitation. However, athletes in single-leg-dominant sports, such as professional soccer players, could develop significant asymmetry between their dominant and nondominant legs, such that symmetry does not act as a viable comparison.
To (1) compare maximal muscular power between the dominant and nondominant legs in healthy young adults, (2) evaluate the effect of a single-leg-dominant sport activity performed at the professional level, and (3) propose a parameter of normality for maximal power difference in the lower limbs of this young adult population.
Controlled laboratory study.
A total of 78 healthy, male, young adults were divided into 2 groups according to sport activity level. Group 1 consisted of 51 nonathletes (mean ± SD age, 20.8 ± 1.5 years; weight, 71.9 ± 10.5 kg) who participated in less than 8 hours a week of recreational physical activity with nonspecific training; group 2 consisted of 27 single-leg-dominant professional soccer players (age, 18.4 ± 0.6 years; weight, 70.1 ± 7.5 kg) who specifically trained and competed at their particular activity 8 hours or more a week. For assessment of maximal leg power, both groups completed the single-leg squat jump test. Dominance was determined when participants completed 2 of 3 specific tests with the same extremity. Statistical analysis included the Student test.
No statistical difference was found for maximal power between dominant and nondominant legs for nonathletes ( = -1.01, = .316) or single-leg-dominant professional soccer players ( = -1.10, = .281). A majority (95%) of participants studied showed a power difference of less than 15% between their lower extremities.
Among young healthy adults, symmetrical power performance is expected between lower extremities independent of the existence of dominance and difference in sport activity level. A less than 15% difference in power seems to be a proper parameter to define symmetrical power performance assessed by vertical single-leg jump tests.
在运动康复过程中，通常建议双下肢之间实现对称的功率表现（差异<15%）。然而，从事单腿主导运动的运动员，如职业足球运动员，其优势腿和非优势腿之间可能会出现显著的不对称，以至于对称性并非一个可行的比较指标。
（1）比较健康年轻成年人优势腿和非优势腿之间的最大肌肉力量，（2）评估职业水平的单腿主导运动活动的影响，（3）为该年轻成年人群体下肢最大力量差异提出一个正常参数。
对照实验室研究。
根据运动活动水平，将78名健康的年轻男性成年人分为2组。第1组由51名非运动员组成（平均年龄±标准差，20.8±1.5岁；体重，71.9±10.5kg），他们每周参加少于8小时的非特定训练的娱乐性体育活动；第2组由27名单腿主导的职业足球运动员组成（年龄，18.4±0.6岁；体重，70.1±7.5kg），他们每周专门训练并参加其特定活动8小时或更长时间。为了评估最大腿部力量，两组都完成了单腿深蹲跳测试。当参与者用同一肢体完成3项特定测试中的2项时确定优势腿。统计分析包括学生t检验。
非运动员（t = -1.01，P = .316）或单腿主导的职业足球运动员（t = -1.10，P = .281）的优势腿和非优势腿之间的最大力量没有发现统计学差异。大多数（95%）参与研究的参与者下肢力量差异小于15%。
在年轻健康成年人中，无论是否存在优势腿以及运动活动水平的差异，双下肢之间预期会有对称的功率表现。力量差异小于15%似乎是通过垂直单腿跳测试评估对称功率表现的一个合适参数。
