Aim. To identify differences in hip muscle strength, knee valgus during a single leg squat (SLS),and function between subjects with Greater Trochanter Pain Syndrome (GTPS) and healthy(H) subjects. To determine associations between pain, function, hip strength and SLS in GPTS subjects. Study Design: Observational study of 14 (3 male 11 female) PFP patients (mean symptom duration 17 months), matched for age height and weight with 14 healthy (H) subjects, All subjects fulfilled specific inclusion and exclusion criteria. Appropriate Ethical approval was obtained. Measures for both groups were Knee valgus angle during SLS using 2D motion capture and SiliconCoach software for measurement of knee valgus angles, hip abduction, internal and external rotation muscle strength using hand held dynamometry, visual analogue scale for pain. Lower Extremity Functional Scale (LEFS). All measures were taken on the affected leg for GPTS subjects and matched for the equivalent leg in healthy group. Strength was reported as a percentage of body weight. SiliconCoach was reliable for intra-rater reliability of knee valgus angle (ICC.996). Results. There were no significant differences in age, height and weight (p=.85,.57,.51 respectively). Significant differences existed in hip abduction strength p=.005(GPTS13.72 (7.65), H21.49 (5.55)) and LEFS p=0.001(GPTS 57.28(16.55), H76.92(4.44)). There were no significant differences in internal and external rotation and knee valgus angles p=.509, p=.505, p=.159 respectively. There was a negative correlation between pain and function r=.879) p=0.001) and a moderate positive correlation between function and hip abduction strength r=.428 (p=.127). This preliminary study shows that patients with GPTS have reduced strength in hip abductor musculature when compared to healthy subjects. This may be due to pain inhibition; however the true causes of pain need to be determined. Pain and to a lesser extent hip abductor strength appears to have an effect on function in GPTS patients. In summary the results indicate that hip abductor muscle strengthening and management strategies to reduce pain should be included in the rehabilitation programmes of patients with GPTS. Further research with larger numbers of subjects should be developed to investigate this subject

In patients with developmental dysplasia of the hip (DDH) chronic joint dislocation induces remodeling of the soft tissue with contractures, muscle atrophy, especially of the hip abductors muscles, leading to severe motor dysfunction, pain and disability (1). The aim pf the present work is to explore if a correct positioning of the prosthetic implants through 3D skeletal modeling surgical planning technologies and an adequate customized rehabilitation can be beneficial for patients with DDH in improving functional performance. The project included two branches: a methodology branch of software development for the muscular efficiency calculation, which was inserted in the Hip-Op surgical planning system (2), developed at IOR to allow surgical planning for patients with complex hip joint impairment; and a clinical branch which involved the use of the developed software as part of a clinical multicentric randomized trial. 50 patients with DDH were randomized in two groups: a simple surgical planning group and an advanced surgical planning with muscular study group. The latter followed a customized rehabilitation program for the strenghtening of hip abductor muscles. All patients were assessed before surgery (T0) and at 3 (T1) and 6 months (T2) postoperatively using clinical outcome (WOMAC, HHS, ROM, MMT, SF12, 10mt WT) and instrumental measures (Dynamometric MT). Pre- and post-operative musculoskeletal parameters obtained by the software (i.e., leg length discrepancy, hip abductor muscle lengths and lever arms) using Hip-Op during the surgical planning were considered. One Way ANOVA for ROM measurement showed a significant improvement at T2 in patients included in experimental group, as well as WOMAC, HHS and SF12 score. The Dynamometric MT score showed significant differences between at T2 (p<0.009). Spearman's rank correlation coefficients showed a significant correlation between both pre- and post-operative abductors lever arm (mm) and hip abductor muscle strength at T2 (ρ = −0.55 pre-op and ρ = −0.51 post-op, p p<0.012 and p<0.02 respectively) and between the operated pre-postoperative leg length variation (mm) and the hip abductor muscle strength (ρ = −0.55, p p<0.013). Results so far obtained showed an improvement of functional outcomes in patients undergoing hip replacement surgery who followed therapeutic diagnostic pathway sincluding a preoperative planning including the assessment of the abductiors lever arm and a dedicated rehabilitation program for the strenghtening of abductios. Particularly interesting is the inverse relationship between the strength of the hip abductor muscles and the variation of the postoperative abductor lever arm

Aim. To determine differences in knee valgus angles produced during a single leg squat and hip muscle strength between healthy subjects and patients with patellofemoral pain (PFP). To determine correlations between variables of hip muscle strength, knee valgus angle and pain. Study design: Observational study of 20 (8 male 12 female) healthy (H) subjects, matched for age height and weight with 20 (8 male 12 female) PFP patients (mean symptom duration 46.75 weeks). All subjects fulfilled specific inclusion and exclusion criteria. Appropriate Ethical approval was obtained. Measures for both groups were Knee valgus angle during a single leg squat using 2D motion capture and SiliconCoach software for measurement of knee valgus angles, hip abduction, internal and external rotation muscle strength using hand held dynamometry, visual analogue scale for pain. Strength was reported as a percentage of body weight. All measures were taken on the affected leg for PFP subjects and matched for the equivalent leg in healthy group. SiliconCoach was determined to be reliable for intra-rater reliability of knee valgus angle (ICC.996). Results. There were no significant differences in age, height and weight (p=.59,.51,.26 respectively). Significant differences existed in hip abduction strength p=.001(PFP 19.93(9.2), H 32.22(8.26)), Hip internal rotation p=0.001 (PFP 12.94(4.35), H 19.53(6.36)), Hip external rotation p=0.001(PFP 10.00(3.07), H 16.26 (4.62)), Knee Valgus Angles p=0.001(PFP 5.31(2.59), H 2.29 (2.35)). No correlations existed between any of the variables including pain. This preliminary study shows that patients with PFP have larger knee valgus angles when doing a single leg squat and significantly weaker hip muscle strength when compared to healthy subjects. The reason for larger knee angles during single leg squat could be hypothesised as being due to weak hip abductor muscles not sufficiently controlling the alignment of the femur. However no correlations were found for these measures, nor were they found for any of the other variables including pain level. In summary the results indicate that hip musculature strengthening of the rotators and abductors and measures to reduce knee valgus angle should be included in the rehabilitation programme of patients with PFP. Further research with larger numbers of subjects should be developed to investigate this subject

Objectives

The aim of this study was to systematically review the literature on measurement of muscle strength in patients with femoroacetabular impingement (FAI) and other pathologies and to suggest guidelines to standardise protocols for future research in the field.