Eccentric hamstring strength in elite track and field athletes on the British Athletics world class performance program

Key points

1. 01Relative eccentric hamstring force was similar between male and female athletes when normalised to body weight (males 5.21 N/kg, females 4.99 N/kg, p=0.62)
2. 02Track and field athletes showed higher relative eccentric force than published values for Australian Rules Football (4.18 N/kg), soccer (4.11 N/kg), and rugby union (3.65 N/kg)
3. 03Long sprint (400m) athletes had a significantly stronger right limb for peak force (p=0.003, d=0.56) and torque (p<0.05), not seen in short sprinters
4. 04No significant difference in relative force or torque was found between previously injured and non-injured limbs, contrasting with studies in other sports
5. 05The Nordbord device was used for assessment, with reported coefficient of variation of 5.8-8.5%

How it was conducted

Design

Clinical measurement, cross-sectional observational study

Participants

Elite British track and field athletes on the World Class Performance Program, tested January to April

Setting

Two British Athletics performance centres

Assessment tool

Nordbord device measuring eccentric hamstring force and torque during Nordic hamstring exercise

Injury history

Retrospective review of electronic medical records plus athlete questionnaire; injury defined as time-loss greater than one hour

Statistical analysis

Two-way ANOVA for gender and event group comparisons; paired t-test for left vs right limb; Cohen's d for effect size; significance set at p<0.05

What they found

• Average male peak force was 438N (8.38N/kg body weight) and average female peak force was 327N (8.54N/kg), with males significantly greater in absolute terms (p<0.01, d=2.92)
• Relative force showed no significant gender difference (males 5.21 N/kg, females 4.99 N/kg, p=0.62)
• Right limb was significantly stronger than left for the overall group in peak force (p<0.01) and peak torque (p<0.01), with a moderate effect size (d=0.51)
• Long sprint (400m) athletes showed right-limb dominance in peak force (p=0.003, d=0.56) and torque (p<0.05); female long sprinters had 8.23% greater right-limb strength
• Short sprint athletes (100/200m) showed no significant left-right asymmetry in peak force (p=0.50) or torque
• Relative torque in previously injured vs non-injured limbs: left 2.01 vs 1.78 N.m/kg (p=0.074), right 2.13 vs 1.89 N.m/kg (p=0.069); no significant differences
• No significant limb force or torque imbalance in athletes with unilateral injury history relative to the contralateral side (left p>0.05, right p>0.09)

Limitations

• Retrospective injury history collection introduces potential inaccuracy; specific hamstring muscle injured was not recorded in all cases
• Testing was conducted across multiple days by different physiotherapists at two sites, with unknown inter-tester reliability
• Only 25% of athletes had no previous hamstring injury, limiting the comparison between injured and uninjured groups
• Cross-sectional design cannot determine whether pre-injury strength deficits existed or whether rehabilitation restored and exceeded prior levels

Why it matters

For patients

Athletes with a history of hamstring injury who have undergone rehabilitation may achieve eccentric strength comparable to uninjured peers in an elite track and field setting.

For clinicians

Right-limb eccentric strength dominance in 400m athletes likely reflects a normal functional adaptation to bend running and should not automatically be flagged as a rehabilitation target or injury risk factor.

For readers

This study establishes the first normative Nordbord eccentric hamstring strength values for elite track and field athletes, showing higher relative strength than field-sport populations and no persistent deficit after previous injury.