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 degrees, 60 degrees and 90 degrees/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 degrees, 60 degrees and 90 degrees/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.