Baseline assessments of strength and balance performance and bilateral asymmetries in collegiate athletes

Key points

1. 01Bilateral asymmetries for all four tests stayed below 10% at the 10th-90th percentile range for both men and women across all 14 sports
2. 02Significant sport effects were found for all five performance variables (p < 0.001), but not for asymmetry variables (p >= 0.36), suggesting asymmetry is more individualized than sport-specific
3. 03Strength and balance were only weakly correlated (r < 0.3), indicating they are largely independent and need to be assessed and trained separately
4. 04Normative data are sex- and sport-specific: men's football and wrestling led push-up force; men's basketball and track led jump height; women's golf consistently ranked lowest across tests
5. 05ICC values above 0.97 confirmed excellent test-retest reliability for the jump and push-up force measures

How it was conducted

Design

Cross-sectional normative data study

Participants

304 male and 195 female NCAA Division I athletes aged 18-26 years from 14 sports

Tests

Maximum push-up test (upper extremity strength), countermovement jump test (lower extremity strength), upper extremity Y-balance reaching test, lower extremity Y-balance reaching test

Measurements

Bilateral ground reaction forces (1,000 Hz force platforms) for push-up and jump; normalized reaching distances for balance tests; bilateral asymmetry index calculated as (dominant minus nondominant) / larger value

Analysis

One-way ANOVA across 14 sports, Pearson correlations between performance and asymmetry variables, false discovery rate adjustment (Benjamini-Hochberg)

What they found

• Bilateral asymmetries were generally less than 10% at the 10th-90th percentile range for all men, all women, and all individual sports across all four tests
• Significant sport effects for all five performance variables (p < 0.001); no significant sport effects for any asymmetry variable (p >= 0.36)
• Mean push-up force: men 0.71 body weight (SD 0.12), women 0.49 body weight (SD 0.07); men's wrestling highest at 0.74 BW mean, women's golf lowest at 0.45 BW mean
• Mean jump height: men 0.44 m (SD 0.08), women 0.30 m (SD 0.06); men's track and field highest at 0.47 m, women's spirit lowest at 0.24 m
• Positive but weak correlations between push force and upper extremity reaching distance, between jump height and lower extremity reaching distance, and between jump force asymmetry and lower extremity reaching distance asymmetry for both sexes (p <= 0.006; r < 0.3)
• ICC values were above 0.97 for jump height and bilateral push and jump forces across three official trials

Limitations

• Warm-up protocols, prior sport activity on test day, footwear, testing time, nutrition, hydration, and sleep were not controlled, limiting internal validity
• Normative data are specific to Division I athletes in 14 sports and cannot be generalized to recreational athletes, lower divisions, or other sports
• The commonly cited 10% asymmetry return-to-play criterion and specific performance percentile thresholds still lack direct evidence linking them to reduced reinjury risk
• The upper extremity reaching test's ability to predict injuries or quantify rehabilitation effects has not yet been established

Why it matters

For patients

Athletes recovering from arm or leg injuries can use the 10% asymmetry guideline as a practical target before returning to full sport, rather than relying on symmetry alone.

For clinicians

Clinicians should collect both performance percentiles and asymmetry scores using sex- and sport-specific norms, and should assess strength and balance independently because they reflect different neuromuscular qualities.

For readers

This study provides the first broad normative database covering upper and lower extremity strength and balance in Division I collegiate athletes, filling a gap that previously existed only for concussion management.