The effect of shear-wave elastography on functional results and muscle stiffness in patients undergoing non-selective and selective open kinetic chain exercises

Abstract

Objectives: this study aims to assess the effect of shear-wave elastography (SWE) on vastus medialis obliquus (VMO) and vastus lateralis (VL) muscle performances and functional outcomes of patients with patellofemoral pain syndrome (PFPS) undergoing non-selective open kinetic chain exercises (NSOKCE) and selective open kinetic chain exercises (SOKCE). Patients and methods: this randomized-controlled clinical trial included a total of 40 patients with PFPS (20 males, 20 females; mean age 46.5 +/- 9.8 years, range, 27 to 65 years) and 40 healthy controls (20 males, 20 females; mean age 36.3 +/- 11.2 years, range, 23 to 71) between February 2013 and August 2014. The participants in each group were randomized into subgroups according to NSOKCE or SOKCE for six weeks. The VMO and VL muscles were assessed with the SWE, thigh circumferences were measured, and the Visual Analog Scale (VAS) and Lysholm Knee Scale (LKS) scores were obtained. Results: the OKCE alleviated pain, improved LKS scores, and increased the thigh circumference in PFPS patients. While the healthy controls were able to increase the resting muscle tone of their VMO, the patients with PFPS failed in their both knees. Similarly, resting as well as contracted VMO and VL muscles' functions were improved significantly by both NSOKCE and SOKCE in the healthy controls. The NSOKCE improved the VAS scores in the PFPS group. The increase in the muscle mass of the affected sides of PFPS patients were more evident with NSOKCE. Conclusion: Our study results show that NSOKCE planning can be preferred over SOKCE, thanks to its contribution to pain improvement and increase in the thigh circumference in the conservative treatment of PFPS.