Clinical Measures and Their Contribution to Dysfunction in Individuals With Patellar Tendinopathy

Patellar tendinopathy (PT) is prevalent in physically active populations, and it affects their quality of living, performance of activity, and may contribute to the early cessation of their athletic careers. A number of previous studies have identified contributing factors for PT; however, their contributions to self-reported dysfunction remain unclear.

The purpose of this investigation was to determine if strength, flexibility, and various lower-extremity static alignments contributed to self-reported function and influence the severity of PT.

Cross-sectional research design.

University laboratory.

A total of 30 participants with PT volunteered for this study (age: 23.4 [3.6] y, height: 1.8 [0.1] m, mass: 80.0 [20.3] kg, body mass index: 25.7 [4.3]).

Participants completed 7 different patient-reported outcomes. Isometric knee extension and flexion strength, hamstring flexibility and alignment measures of rearfoot angle, navicular drop, tibial torsion, q-angle, genu recurvatum, pelvic tilt, and leg length differences were assessed. Pearson's correlation coefficients were assessed to determine significantly correlated outcome variables with each of the patient-reported outcomes. The factors with the highest correlations were used to identify factors that contribute the most to pain and dysfunction using backward selection, linear regression models.

Correlation analysis found significant relationships between questionnaires and body mass index (r = -.35-.46), normalized knee extension (r = .38-.50) and flexion strength (r = -.34-.50), flexibility (r = .32-.38, q-angle (r = .38-.56), and pelvic tilt (r = -.40). Regression models (R² = .22-.54) identified thigh musculature strength and supine q-angle to have greatest predictability for severity in patient-reported outcomes.

These findings put an emphasis of bodyweight management, improving knee extensor and flexor strength, and posterior flexibility in PT patients.