Mersmann F, Bohm S, Schroll A, Boeth H, Duda G, Arampatzis A
Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.
Center for Sports Science and Sports Medicine, Berlin, Germany.
Scand J Med Sci Sports. 2014 Aug;24(4):e283-9. doi: 10.1111/sms.12166. Epub 2013 Dec 27.
Adolescence may be regarded as a critical phase of tissue plasticity in young growing athletes, as the adaptation process of muscle-tendon unit is affected by both environmental mechanical stimuli and maturation. The present study investigated potential imbalances of knee extensor muscle strength and patellar tendon properties in adolescent compared with middle-aged athletes featuring long-term musculotendinous adaptations. Nineteen adolescent elite volleyball athletes [(A), 15.9 ± 0.6 years] and 18 middle-aged competitively active former elite volleyball athletes [(MA), 46.9 ± 0.6 years] participated in magnetic resonance imaging and ultrasound-dynamometry sessions to determine quadriceps femoris muscle strength, vastus lateralis morphology and patellar tendon mechanical and morphological properties. There was no significant age effect on the physiological cross-sectional area of the vastus lateralis and maximum knee extension moment (P > 0.05) during voluntary isometric contractions. However, the patellar tendon cross-sectional area was significantly smaller (A: 107.4 ± 27.5 mm(2) ; MA: 121.7 ± 39.8 mm(2) ) and the tendon stress during the maximal contractions was significantly higher in adolescent compared with the middle-aged athletes (A: 50.0 ± 10.1 MPa; MA: 40.0 ± 9.5 MPa). These findings provide evidence of an imbalanced development of muscle strength and tendon mechanical and morphological properties in adolescent athletes, which may have implications for the risk of tendon overuse injuries.
青春期可被视为年轻成长中运动员组织可塑性的关键阶段，因为肌腱单元的适应过程受到环境机械刺激和成熟度的双重影响。本研究调查了与具有长期肌腱适应性的中年运动员相比，青少年膝关节伸肌力量和髌腱特性的潜在失衡情况。19名青少年精英排球运动员[（A组），15.9±0.6岁]和18名中年曾参加过竞技比赛的前精英排球运动员[（MA组），46.9±0.6岁]参与了磁共振成像和超声测力测试，以确定股四头肌力量、股外侧肌形态以及髌腱的力学和形态学特性。在自愿等长收缩过程中，股外侧肌的生理横截面积和最大膝关节伸展力矩不存在显著的年龄效应（P>0.05）。然而，与中年运动员相比，青少年的髌腱横截面积显著更小（A组：107.4±27.5mm²；MA组：121.7±39.8mm²），且在最大收缩时的肌腱应力显著更高（A组：50.0±10.1MPa；MA组：40.0±9.5MPa）。这些发现为青少年运动员肌肉力量与肌腱力学和形态学特性的发育失衡提供了证据，这可能对肌腱过度使用损伤的风险具有影响。
