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

CONTEXT: Patellar tendinopathy 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 patellar tendinopathy however their contributions to self-reported dysfunction remain unclear.

OBJECTIVE: 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 patellar tendinopathy.

DESIGN: Cross sectional research design.

SETTING: University Laboratory.

PARTICIPANTS: 30 participants with patellar tendinopathy volunteered for this study (age: 23.4±3.6 years, height: 1.8±0.1m, mass: 80.0±20.3kg, BMI: 25.7±4.3).

MAIN OUTCOME MEASURES: Participants completed seven 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.

RESULTS: Correlation analysis found significant relationships between questionnaires and BMI (r=-0.35-0.46), normalized knee extension (r=0.38-0.50) and flexion strength (r=-0.34-0.50), flexibility (r=0.32- -0.38, q angle (r=0.38-0.56) and pelvic tilt (r=-0.40). Regression models (R(2)= 0.22-0.54) identified thigh musculature strength and supine q angle to have greatest predictability for severity in patient-reported outcomes.

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