The effect of a single high velocity low amplitude hip mobilization on strength in subjects with knee injuries.

BACKGROUND: Manual therapy have been used as a disinhibitory intervention to increase muscle activation before performing functional tasks that are limited by weakness. Knee injuries are commonly associated with weakness in quadriceps and gluteus. Currently, there is no evidence to support anecdotal experience that a hip distraction mobilization improves muscle performance in subjects with knee injuries and lower extremity weakness. OBJECTIVES: To determine if a hip distraction mobilization would result in an immediate change of maximal force output of the quadriceps and gluteus. DESIGN: Non-controlled observational pre-post design. METHODS: Forty individuals with knee pathology were included. Subjects underwent quadriceps, gluteus maximus, and gluteus medius muscle strength assessment before a single hip distraction of the symptomatic side. An immediate re-assessment of muscle strength of both symptomatic and asymptomatic sides followed the mobilization. RESULTS: /findings: Comparing pre-to post-mobilization strength on the symptomatic side, a significant increase was found with the gluteus maximus (average change = 2.0 kg [95%CI 0.6-3.4]; p < 0.01) but not gluteus medius (0.2 kg [-0.7-1.0]; p = 0.71) or quadriceps (0.1 kg [-1.4-1.7]; p = 0.86). When comparing the strength on the symptomatic side in subjects with weakness greater than the MDD95 (0.7-2.9 kg), a significant increase was again found for gluteus maximus (4.7 kg [2.6-6.8]; p < 0.01) but not for gluteus medius (0.2 kg [-1.0-1.4]; p = 0.71) or quadriceps (1.6 kg [-0.7-3.9]; p = 0.15). CONCLUSION: A single hip distraction resulted in a significant increase in gluteus maximus strength but did not produce a change in gluteus medius or quadriceps strength in subjects with knee injuries.

STRENGTHENING THE GLUTEUS MAXIMUS IN SUBJECTS WITH SACROILIAC DYSFUNCTION.

STUDY DESIGN: Case series. BACKGROUND AND PURPOSE: The literature has emphasized the use of exercise as an intervention for individuals with lumbopelvic pain. However, there is limited information to guide clinicians in exercise selection for those with sacroiliac (SI) joint dysfunction. Altered function of the gluteus maximus has been found in those with SI joint dysfunction. The objective of this case series was to assess the effectiveness of an exercise program directed at increasing gluteus maximus strength in those with clinical tests positive for SI joint dysfunction. CASE DESCRIPTIONS: The eight subjects in this series presented with lumbopelvic pain and clinical evidence of SI joint dysfunction. Each subject underwent 10 treatments over five weeks consisting of five exercises directed at strengthening the gluteus maximus. Radiological assessment and clinical examination were performed to rule out potential concurrent pathologies. Visual analog pain scale, the Oswestry Disability Index, and strength assessed via hand held dynamometry were measured pre- and post-intervention. OUTCOMES: A significant (p<0.001) weakness in gluteus maximus was noted when comparing the uninvolved and involved sides pre-intervention. After completing the strengthening exercise program over 10 visits, statistically significant (p<0.002) increases in gluteus maximus strength and function were found, as well as a decrease in pain. All subjects were discharged from physical therapy and able to return to their normal daily activities. DISCUSSION: The results of this case series support the use of gluteus maximus strengthening exercises in those with persistent lumbopelvic pain and clinical tests positive for SI joint dysfunction.