Mild Quadriceps and Hamstring Strength Deficits Do Not Persist After Sport-Related Concussion.

Area of Science:

• Sports Medicine
• Neurology
• Orthopedics

Background:

• Sport-related concussion (SRC) is associated with an increased risk of lower extremity musculoskeletal injuries.
• Unresolved motor control deficits, such as muscle weakness, may contribute to this heightened injury risk following SRC.

Purpose of the Study:

• To investigate quadriceps and hamstring muscle strength in athletes after SRC at return to sport and 30 days later.
• To compare muscle strength deficits in athletes with SRC to a matched control group.

Main Methods:

• A prospective matched cohort study involved 31 athletes with SRC and matched controls.
• Isokinetic testing assessed quadriceps and hamstring strength at 60 and 180 deg/s, normalized to body mass.
• Data were analyzed using repeated measures general linear models with effect size calculations.

Main Results:

• No significant strength differences were found between athletes with SRC and controls at return to play or 30 days later.
• Effect sizes for strength deficits were small at initial assessment (d = 0.117 to 0.353) and further reduced at follow-up (d = -0.191 to 0.252).
• Quadriceps and hamstring strength deficits were minimal in the SRC group and decreased over the 30-day period.

Conclusions:

• Minimal quadriceps and hamstring strength deficits exist in athletes with SRC at return to play, diminishing over 30 days.
• Strength deficits are unlikely to be a primary factor in the increased risk of lower extremity injuries post-SRC.
• Implementing strength training before return to play could help mitigate any residual strength deficits.