STUDY DESIGN: Descriptive, correlational, anatomical laboratory study. OBJECTIVES: To investigate the association between the morphology of the vastus medialis obliquus (VMO) and patellar alignment in patients with patellofemoral pain syndrome (PFPS). BACKGROUND: It has long been presumed that PFPS results from patellar malalignment. Strengthening of the VMO has been suggested as an intervention to treat individuals with PFPS, through correction of abnormal patellar tracking. However, the exact role of the VMO in the etiology and treatment of PFPS is not clear. METHODS AND MEASURES: This study included 58 patients with PFPS, of which 31 had bilateral involvement. A total of 89 knees were imaged with a Merchant's view radiograph at 45° of knee flexion to measure patellar alignment consisting of patellar tilt and congruence angles. Those 89 knees were also examined with sonography with the knee in full extension and quadriceps relaxed to measure VMO morphology and additional characteristics such as insertion level, insertion ratio, fiber angle, and volume. The level of association between radiographic and sonographic measurements was explored to determine any relationship between patellar alignment and morphology of the VMO. RESULTS: The patellar tilt angle was negatively correlated with the VMO insertion level (r = –.58, P<.05), insertion ratio (r= –.52, P<.05), and volume (r = –.45, P<.05). In addition, the patellar congruence angle was negatively correlated with the VMO fibers angle (r = –.23, P<.05). CONCLUSIONS: This study showed that some aspects of VMO morphology, measured in full knee extension with the quadriceps relaxed, were associated with patellar alignment measured with the knee at 45° of flexion. Whether or not VMO morphology serves as a predictor of patella alignment with the knee extended should be the focus of future investigations.

J Orthop Sports Phys Ther. 2008;38(4):196-202, published online 21 November 2007. doi:10.2519/jospt.2008.2568

STUDY DESIGN: A randomized clinical trial design. OBJECTIVE: To investigate the efficacy of high, repetitive, target-matching foot-stepping exercise (TMFSE) performed in a sitting position on proprioception, functional score, and walking velocity for patients with knee osteoarthritis (OA). BACKGROUND: Researchers have suggested that exercises to address knee OA should include proprioceptive training. However, most patients cannot tolerate conventional proprioceptive training performed in a standing position. METHODS AND MEASURES: Forty-nine subjects (mean age ± SD, 63.3 ± 8.1) with knee OA were randomly assigned to the exercise or no intervention groups. The exercise group practiced TMFSE in sitting, 3 sessions weekly for 6 weeks. All subjects underwent assessments of knee reposition error, functional incapacity score, and walking velocity prior to and after intervention. RESULTS: The TMFSE significantly improved reposition error from a mean ± SD of 3.0° ± 1.6° to 1.5° ± 0.6°, walking velocity on ground level from 44.1 ± 2.9 to 38.6 ± 2.5 sec for 60 meters, time to complete a stairs task from 34.2 ± 2.1 to 26.5 ± 2.3 seconds, time to complete a figure-of-eight from 51.3 ± 6.7 to 29.1 ± 3.6 seconds, and score on a functional incapacity scale from 12.0 ± 3.1 to 4.9 ± 1.7, in subjects with knee OA after 6-week intervention (P <.0125). In contrast, the control group showed no change in any of the measured tests. CONCLUSION: TMFSE in sitting appears to be an option for exercise in patients with mild to moderate knee OA. This may be an especially attractive option for patients who may have pain with weight-bearing exercises. A longitudinal study with a larger sample size is needed to confirm the potential use of TMFSE for patients with knee OA.

J Orthop Sports Phys Ther. 2008;38(1):19-25, published online 29 August 2007, doi:10.2519/jospt.2008.2512

KEY WORDS: arthritis, OA, tibiofemoral joint