Clinical and Functional Comparison between Adolescent Dancers with and without Patellofemoral Pain

Background: Patellofemoral pain (PFP) is common among young dancers. Currently, there is no clear indication as to which measures are most important in discriminating between young dancers with and without PFP.

Aim: To examine dancers with and without PFP for differences in anthropometric parameters, dance background and intensity, knee clinical assessment, dynamic balance, proprioceptive ability and lower extremity strength.

Methods: One hundred and thirty-two young dancers (mean age 13.4±0.9) from 7^th grade (39 dancers), 8^th grade (37 dancers), and 9^th grade (56 dancers) were interviewed for dance background and intensity and were assessed for PFP. Anthropometric measurements (e.g. height and weight), physical examination (e.g. grinding test), dynamic balance (with YBT-kit), proprioception ability (with AMEDA-device) and lower extremity strength (with hand-held dynamometer) examinations were performed.

Results: In total, 27 dancers (20.5%) were identified with unilateral PFP, 56 dancers (42.4%) were identified with bilateral PFP, and 49 dancers (37.1%) had no PFP. In 7^th grade, dancers with PFP had significantly weaker hip abductors and weaker ankle dorsiflexors compared with dancers without PFP (p.05). The dancers with PFP in 7^th grade had higher prevalence of positive grinding test and higher prevalence of positive patellar inhibition compared with healthy dancers (p= .038 and .007, respectively). In 8^th grade no significant differences were found between dancers with and without PFP. In 9^th grade, PFP dancers had longer leg length, they reported more h/week of dance practice in the previous year, had worse proprioception ability and worse dynamic postural balance compared with healthy 9^th grade dancers.

Conclusions: As PFP in young dancers may be influenced by morphologic parameters, dance intensity, strength deficits and lower postural balance and proprioception ability, screening the young dancer for factors related to PFP is important in order to assist health care professionals in establishing effective intervention programs and preventative strategies, and hopefully reducing the risk for PFP.