Patients with patellofemoral pain have lower soft tissue flexibility of the kinetic chain compared to healthy controls: A case-control study.

INTRODUCTION: Patellofemoral pain (PFP) is a common musculoskeletal condition. Lower limb range of motion (LLROM) evaluates soft tissue flexibility over multiple joints as part of the kinetic chain. The aims were to study: 1) the reliability of a new LLROM test; 2) differences in LLROM between PFP patients and controls; and 3) the relationship between LLROM and pain-free knee function. METHODS: Patients with PFP and matched controls were recruited from a university campus and private physiotherapy clinics, while observers were blinded for health status. Testing LLROM for maximal knee flexion and hip adduction and the sum of these (total ROM) were performed. Measures of reliability (ICC2,1) were established. Univariate linear regression between LLROM and health status and multivariate analysis between LLROM and knee function were performed. RESULTS: Patients (n = 32 (7 male/25 female, age = 22, BMI = 22.7)) and controls (n = 32 (7 male/25 female, age = 20, BMI = 22.3)) were included. The ICC's for intra- and interobserver reliability ranged from 0.83 (95%CI 0.30-0.93) to 0.89 (0.72-0.95). Symptomatic legs had 7°(3-11, p = 0.014) lower knee flexion, 6°(4-8, p ≤ 0.001) lower hip adduction and 13°(8-17, p ≤ 0.001) lower total ROM than non-symptomatic legs. Multivariate analysis revealed an association between total ROM and pain-free knee function (R2 = 0.438, F = 6.544, p ≤ 0.001). CONCLUSIONS: The new LLROM test was found to be reliable. Patients with PFP had lower LLROM, which was associated with impaired pain-free knee function. Whether improving soft tissue flexibility results in enhanced pain-free knee function should be the subject of future research.

Short-term effectiveness of an intervention targeting lower limb range of motion on pain and disability in patellofemoral pain patients: A randomized, non-concurrent multiple-baseline study.

INTRODUCTION: Patellofemoral pain (PFP) is a common and often long-standing musculoskeletal condition. Evidence of the effectiveness of interventions addressing soft tissue flexibility is conflicting and of inconsistent scientific quality. However, reduced soft tissue flexibility can negatively affect patellofemoral joint kinematics. Lower limb range of motion (LLROM) reflects soft tissue flexibility throughout the kinetic chain. The aim was to evaluate the short-term effectiveness of an intervention targeting LLROM on pain and disability in patients with PFP. METHODS: A randomized, non-concurrent, multiple-baseline single-case design with a two-week intervention phase and baseline and postintervention phase with varying length was conducted. Eight participants (5 females, 3 males) of age 19(±1.6) years, weekly sports participation 12(±3.1) hours and 17(±14) months symptom duration were included. The Anterior Knee Pain Scale - Dutch Version (AKPS-DV) and the Patient Specific Complaint Scale (PSCS) were administered twice a week. After allocating participants to one of four subgroups of reduced LLROM the intervention was applied. The intervention consisted of soft tissue techniques (mobilization, taping, and stretching). RESULTS: Participant 3 and 6 showed a medium and small but statistically significant positive effect on the AKPS-DV. Participant 2 showed a large and statistically significant positive effect on the PSCS. CONCLUSIONS: This study provides moderate evidence that an intervention targeting LLROM in patients with PFP reduces pain and disability in the short-term. Further research is needed to evaluate the long-term effectiveness and optimize individual treatment outcomes.