Adolescent elite skiers with and without cam morphology did change their hip joint range of motion with 2 years follow-up

Purpose To investigate how range of motion of the hips and the lumbar spine are affected by continued elite, alpine skiing in young subjects, with and without a magnetic resonance imaging verified cam morphology, in a 2-year follow-up study. The hypothesis is that skiers with cam morphology will show a decrease in hip joint range of motion as compared with skiers without cam, after a 2-year follow-up. Method Thirty adolescent elite alpine skiers were examined at the baseline (mean age 17.3 +/- 0.7 years) and after 2 years. All skiers were examined for the presence of cam morphology (alpha-angle > 55 degrees) using magnetic resonance imaging at the baseline. Clinical examinations of range of motion in standing lumbar flexion and extension, supine hip flexion, internal rotation, FABER test and sitting internal rotation and external rotation were performed both at the baseline and after 2 years. Results Skiers with and without cam morphology showed a significant decrease from baseline to follow-up in both hips for supine internal rotation (right: mean - 13.3 degrees and - 10.9 degrees [P < 0.001]; left: mean - 7.6 degrees [P = 0.004] and - 7.9 degrees [P = 0.02]), sitting internal rotation (right: mean - 9.6 degrees and - 6.3 degrees [P < 0.001]; left: mean - 7.6 degrees [P = 0.02] and - 3.3 degrees [P = 0.008]) and sitting external rotation (right: mean - 16.9 degrees and - 11.4 degrees and left: mean - 17.9 degrees and - 14.5 degrees [P < 0.001]) and were shown to have an increased left hip flexion (mean + 8.4 degrees and + 4.6 degrees [P = 0.004]). Skiers with cam were also shown to have an increased right hip flexion (mean + 6.4 degrees [P = 0.037]). Differences were found between cam and no-cam skiers from baseline to follow-up in the sitting internal rotation in both hips (right: mean 3.25 degrees, left: mean 4.27 degrees [P < 0.001]), the right hip flexion (mean 6.02 degrees [P = 0.045]) and lumbar flexion (mean - 1.21 degrees, [P = 0.009]). Conclusion Young, elite alpine skiers with cam morphology decreased their internal rotation in sitting position as compared with skiers without the cam morphology after 2 years of continued elite skiing.