Clinical Research Directory

Q-Angle, Segment Length, Quadriceps, and Knee Alignment in Soccer Players

The aim of this study is to investigate the relationship of Q-angle, lower extremity segment lengths, and quadriceps muscle activation with dynamic knee alignment during a single-leg squat in active soccer players. Study hypotheses: H1: There is a significant relationship between Q-angle and dynamic knee alignment during a single-leg squat in active soccer players. H2: There is a significant relationship between femur length and dynamic knee alignment during a single-leg squat in active soccer players. H3: There is a significant relationship between tibia length and dynamic knee alignment during a single-leg squat in active soccer players. H4: There is a significant relationship between the ratio of lower extremity segment lengths and dynamic knee alignment during a single-leg squat in active soccer players. H5: There is a significant relationship between the level of quadriceps muscle activation and dynamic knee alignment during a single-leg squat in active soccer players. H6: When Q-angle, lower extremity segment lengths, and quadriceps muscle activation are evaluated together, they are significantly associated with dynamic knee alignment during a single-leg squat in active soccer players.

Weighted vs Unweighted Plyometric Conditioning on Vertical Jump Performance in Young Male Soccer Players

Explosive lower-limb power is essential for soccer performance and contributes to jumping, sprinting, and rapid changes of direction. Plyometric exercises are commonly used during warm-up to improve neuromuscular readiness and may enhance subsequent athletic performance through post-activation performance enhancement (PAPE). However, it remains unclear whether adding external load during plyometric conditioning provides greater benefits than performing the same exercises without additional load. The purpose of this study is to compare the acute effects of weighted and unweighted plyometric conditioning on vertical jump performance in young male soccer players. Participants complete two experimental sessions separated by 48 hours. In one session, they perform a standardized single-leg plyometric protocol without external load, and in the other session they perform the same protocol while wearing a weighted vest equivalent to 10% of their body mass. Vertical jump height is assessed before exercise and at several time points after the conditioning activity to examine the time course of performance changes. The findings of this study are expected to improve understanding of the optimal use of weighted plyometric conditioning during warm-up and provide practical guidance for coaches and sports practitioners seeking to maximize explosive performance before training and competition.