Inter-limb musculoskeletal differences in competitive ten-pin bowlers: a preliminary analysis.

OBJECTIVES To compare musculoskeletal characteristics of the loaded and non-loaded forearm and upper leg of competitive ten-pin bowlers. METHODS 10 competitive bowlers (30.6∓6.8 yrs) had their areal bone mineral density (aBMD) and body composition measured with Dual Energy X-ray Absorptiometry (DXA). Volumetric bone mineral density (vBMD) and bone characteristics were assessed at 4% and 66% of the limb length of each radius and 50% of the limb length of each femur using a pQCT. Bone and muscle characteristics of the loaded and non-loaded limbs were compared and analyzed using paired t-tests. RESULTS The loaded arm of competitive bowlers had significantly (p<0.05) greater bone free lean body mass (BFLBM) (5%) and ultra distal radius site (UD radius) aBMD (6.3%) compared to the non-loaded side. Cortical and trabecular vBMD was significantly (p<0.05) greater (1.3%, 4.8%) at the radius 66% and 4% sites in the loaded forearm, respectively. aBMD of the femoral neck, trochanter, and total hip were significantly greater (12.2-15.6%) in the slide leg. Total (5.2%) and cortical (9.2%) bone areas, total (8.2%) and cortical (8.7%) bone mineral content (BMC), and cortical wall thickness (9%) were significantly greater at the 50% femur site in the slide leg compared to the contralateral side. CONCLUSION The femoral shaft of bowlers adapts by increasing bone area and cortical thickness without a change in vBMD, while the loaded radius adapts by increasing vBMD.