Knee and ankle strength and lower extremity power in adolescent female ballet dancers

The aims of this study were twofold: 1. to compare the strength of four muscle groups of the lower limb (quadriceps [Q], hamstrings [H], plantar flexors [PF], and dorsiflexors [DF]) between female adolescent ballet dancers (BALs) and basketball players (BBs) over three angular velocities (30°, 60° and 90°/sec) and two types of contraction (eccentric and concentric); and 2. to compare peak and mean power between the BALs and BBs. Eleven BALs (age: 15.8 ± 1.2 years; stature: 163.9 ± 6.2 cm; body mass: 56.3 ± 5.7 kg; Tanner stage 4: N = 10, stage 5: N = 1) and ten BBs (age: 15.8 ± 1.0 years; stature: 172.5 ± 5.8 cm; body mass: 63.2 ± 10.0 kg; Tanner stage 4: N = 7, stage 5: N = 3) volunteered to participate. Each participant performed one habituation session and one testing session on a Biodex isokinetic dynamometer to determine peak torque. Three angular velocities (30°, 60° and 90°/sec) were used for each muscle group. To determine absolute and relative peak and mean power, participants performed a 30 second anaerobic Wingate test on a cycle ergometer. There were no significant differences in peak torque for Q, H, PF, and DF between the groups. Basketball players produced greater absolute peak power [569.7 ± 82.2 vs. 454.6 ± 79.3 W (p < .05)], relative peak power [9.1 ± 1.3 vs. 8.1 ± 1.0 W/kg body mass (p < .05)], absolute mean power [428.4 ± 53.9 vs. 333.7 ± 68.2 W (p < .05)] and relative mean power [6.83 ± 0.7 vs. 5.9 ± 0.7 W/kg (p < .05)] than BALs. Ballet dancers and BBs had similar isokinetically measured lower extremity muscular strength, but BALs generated lower levels of peak power and mean power compared to BBs.