Muscle-Tendon Imbalances

Muscle-tendon imbalance is explained as a mismatch between muscle force capacity and tendon stiffness, where muscles become stronger without a corresponding increase in tendon stiffness. The lecture defines tendon strain during maximal voluntary contraction as a key indicator of this problem, using 9% strain as a threshold for clear imbalance. Learners are introduced to data showing that such imbalances are relatively common in athletes, especially with age and in sports dominated by jumping, rapid direction changes, and plyometric loading. The main causes covered include faster adaptation of muscle than tendon, neural strength gains that occur before tendon structure can adjust, and different responses of muscle and tendon to training loads. Moderate-load, fatiguing training and high-rate plyometric work may strengthen muscle without adequately stimulating tendon adaptation. Additional factors such as loading volume and genetics are also discussed. The consequences include a higher risk of tendon pain, particularly patellar tendinopathy, and possible negative effects on muscle activation during movement. Prevention focuses on regular tendon-focused training with moderate to high intensity, low volume, slow loading, and longer time under tension.