Sport-discipline and age-related differences in knee extensor musculotendinous morphology and function

Area of Science:

• Sports Medicine
• Biomechanics
• Exercise Physiology

Background:

• Sport-specific demands and progression from youth to elite levels can impact knee musculotendinous morphology and function.
• These changes may contribute to knee pain and injury incidence in athletes.

Purpose of the Study:

• To assess sport- and age-related differences in knee extensor musculotendinous morphology and function.
• To evaluate self-reported knee pain and injury incidence across different sports and age categories.

Main Methods:

• Ninety male athletes across cycling, basketball, and ice hockey were studied, divided into youth (U19) and elite age categories.
• Ultrasonography measured muscle thickness and patellar tendon cross-sectional area (CSA).
• Maximal isometric/isokinetic torque, countermovement jump (CMJ) height, anterior knee pain (AKP), and knee injury history (KIJ) were assessed.

Main Results:

• Elite athletes exhibited larger quadriceps muscle size (QMS) and greater muscle/tendon size and maximal torque compared to youth, though differences diminished when normalized for body mass.
• Cyclists had a higher QMS to body mass ratio but lower patellar tendon stress and CMJ height than basketball and ice hockey players.
• Elite athletes reported significantly higher rates of AKP and KIJ than youth athletes.

Conclusions:

• Cycling is associated with a favorable muscle size-to-body mass ratio and lower tendon stress.
• Basketball and ice hockey demonstrate superior explosive performance.
• Despite coordinated muscle-tendon development from youth to elite levels, elite athletes experience increased knee pain and injury incidence.