18/10/2025
📃📌 Hamstring Injuries: Why They Happen, What Works, and The Hidden Keys to Prevention
▪️ Hamstring injuries are a massive challenge in sports, known for their high incidence and recurrence rates.
▪️ They account for about 10% of all injuries in field-based sports, with recurrence rates ranging widely from 15% to 70%.
▪️ Despite decades of intervention strategies, such as resistance training, the prevalence remains stubbornly high, demanding a deeper look into both injury mechanisms and prevention strategies.
⚙️ The Mechanism of Hamstring Injury
▪️ Most hamstring injuries (over 80%) occur during high-speed running.
▪️ The most vulnerable phase is the late swing phase, where the hamstrings act eccentrically.
⬜ 1. The Vulnerable Position:
During late swing, the hamstrings must produce large eccentric forces while operating at long muscle lengths to decelerate the leg.
Animal studies confirm that muscle injuries often happen when high strains occur at long muscle lengths.
⬜ 2. The Primary Victim:
The biceps femoris long head (BFlh) is the muscle most commonly affected.
Musculoskeletal modeling suggests the BFlh muscle–tendon unit (MTU) length peaks significantly longer (at 112% of upright standing length) compared to other hamstring muscles during this phase, placing significantly more strain on it.
⬜ 3. The Core Problem:
Injuries in this phase typically result from insufficient or delayed neural activation, or an inability to produce the necessary force to resist active overstretching.
▪️ Two major risk factors are consistently identified: low eccentric strength and short muscle fascicle lengths.
▪️ Athletes with short resting fascicle lengths (
