Examining the Association between Lower-body Bone Mineral Composition and Ground Reaction Force in American Football Players

Mechanical loading is a primary determinant of skeletal adaptation, particularly in collision-based sports such as American football. PURPOSE: The purpose was to examine the relationship between lower body bone mineral characteristics and unilateral ground reaction force production in male athletes. The study was conducted to examine whether force-production capacity is related to skeletal mineralization and limb asymmetry. METHODS: One hundred and ten American football athletes participated in the study. Lower body bone mineral composition (BMC), lean mass index, and limb asymmetry were measured using dual-energy X-ray absorptiometry (DXA). A unilateral vertical jump test was performed using the DARI Motion ® markerless motion capture system. DARI ® quantifies the right and left limb peak ground reaction force (GRF) and rate of force development (RFD). Descriptive statistics were used to summarize all variables in the study. Relationships between bone measures and unilateral force production metrics were examined using Pearson r correlation analyses. Statistical significance was set at p ≤ 0.05. RESULTS: Descriptive analyses demonstrated that exposure to high external loading demands have higher lower-limb BMC and higher unilateral GRF. The findings showed high positive correlations between unilateral peak GRF and the BMC of the same limb. Right limb peak GRF was strongly associated with right leg BMC (r = 0.59, p < .001), while left limb peak GRF was strongly associated with left leg BMC (r = 0.53, p < .001). Unilateral GRF values were similar between the right (2334.21 ± 503.7 N) and left limbs (2312.56 ± 468.58 N), with GRF consistently associated with higher skeletal mineralization. CONCLUSION: Overall results indicate a relationship between unilateral force output and lower-body bone health in football players. Demonstrating the importance of integrating DXA and DARI ® for monitoring bone health, neuromuscular performance, and asymmetry in high impact athletes.