Gluteal Muscle Size and Quality in Professional Ballet Dancers Compared to Non-Dancing Athletes.

INTRODUCTION: Professional ballet dancers load their hips in extreme ranges of motion and commonly report hip pain. Evaluating gluteal muscle size and quality may help guide exercise programs. Objectives of this study were to compare gluteal muscle size and quality (fatty infiltration) in ballet dancers compared to athletes; and to investigate the relationship between gluteal muscle size and quality, and reports of hip-related pain. METHODS: This study was a case-control design. Professional ballet dancers (current and retired, n = 49, mean age 35 years, range 19-63) and age and sex-matched athletes (current and retired, n = 49) underwent magnetic resonance imaging of both hips. Muscle cross-sectional areas (CSA) were obtained at standardized landmarks for gluteus maximus (GMax) and gluteus medius (GMed). Full muscle volume was calculated for gluteus minimus (GMin). Fatty infiltration was rated using the Goutallier classification system. Muscle size was compared between groups using linear mixed models. Fatty infiltration was compared using a mixed model binary logistic regression. Hip-related pain, participation status, limb side and sex were included as covariates. RESULTS: Ballet dancers had significantly larger GMax (upper P < .01, middle P < .01, lower P = .01) and GMed (level of anterior inferior iliac spine P < .01, greater sciatic foramen P < .01) CSA and larger GMin volume (P < .01), when normalized to weight. There was no difference in fatty infiltration ratings between dancers and non-dancing athletes. Retired dancers and athletes reporting hip-related pain were more likely to have fatty infiltration in GMax lower (P = .04). CONCLUSION: Gluteal muscles are larger in ballet dancers compared to athletes suggesting high-level loading of these muscles. There is no relationship between hip-related pain and gluteal muscle size. Dancers and athletes have comparable muscle quality.

A pilot randomised trial comparing individualised physiotherapy versus shockwave therapy for proximal hamstring tendinopathy: a protocol.

PURPOSE: Proximal hamstring tendinopathy (PHT) presents as localised lower buttock pain with tasks such as squatting and sitting. It is a condition that occurs at all ages and levels of sporting participation and can cause disability with sport, work, and activities of daily living. This paper details a pilot trial protocol for investigating the effectiveness of individualised physiotherapy compared to extracorporeal shockwave therapy (ESWT) on pain and strength in people with PHT. METHODS: The study is an assessor-blinded, pilot randomised controlled trial (RCT). One hundred participants with PHT will be recruited from the local community and sporting clubs. Participants will be randomised to receive six sessions of either individualised physiotherapy or ESWT, with both groups also receiving standardised education and advice. Primary outcomes will be global rating of change on a 7-point Likert scale, and the Victorian Institute of Sport-Hamstring (VISA-H) scale, measured at 0, 4, 12, 26 and 52 weeks. Secondary outcomes will include sitting tolerance, the modified Physical Activity Level Scale, eccentric hamstring strength, modified Tampa scale for kinesiophobia, the Örebro Musculoskeletal Pain Screening Questionnaire Short Form (ÖMPSQ-SF), Numerical Pain Rating Scale (NPRS) for average and worst pain, participant adherence, the Pain Catastrophizing scale, satisfaction scores, and quality of life. Data will be analysed on an intention to treat basis, with between-group effects estimated using linear mixed models for continuous data and Mann Whitney U tests for ordinal data. CONCLUSIONS: This pilot RCT will compare individualised physiotherapy versus ESWT for PHT. The trial will determine feasibility and estimated treatment effects to inform a definitive trial in the future. TRIAL REGISTRATION: The trial has been prospectively registered with the Australia & New Zealand Clinical Trials Registry (ACTRN12621000846820), registered 1 July 2021, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373085.

Does Menopausal Hormone Therapy, Exercise, or Both Improve Pain and Function in Postmenopausal Women With Greater Trochanteric Pain Syndrome? A 2 × 2 Factorial Randomized Clinical Trial.

BACKGROUND: Greater trochanteric pain syndrome (GTPS) is a debilitating chronic condition, most prevalent in postmenopausal women. A positive association between high estrogen levels and tendon health may exist, and postmenopausal women have reduced estrogen. Menopausal hormone therapy (MHT) may reduce the incidence of tendon abnormality, particularly when combined with exercise. PURPOSE: To determine the effect of MHT and exercise on tendon pain and function in postmenopausal women with GTPS. STUDY DESIGN: Randomized controlled clinical trial; Level of evidence, 1. METHODS: Postmenopausal women (N = 132; n = 12, lost to follow-up) with GTPS were randomized into MHT and placebo transdermal cream groups combined with tendon-specific or sham exercise. All groups received education about avoiding gluteal tendon compression and load management throughout 12 weeks of intervention. The primary outcome was the Victorian Institute of Sport Assessment for gluteal tendinopathy (VISA-G), and secondary outcomes were measured at baseline and at 12 and 52 weeks. The Global Rating of Change was assessed at 12 and 52 weeks. A linear mixed-effects model was used to assess differences. Body mass index (BMI) was included as a covariate. RESULTS: All participant groups improved over time (baseline vs 12 weeks, P < .001; baseline vs 52 weeks, P < .001). There was no difference among exercise groups measured by all outcomes (VISA-G: baseline, P = .97, mean difference [MD] = 0.10; 12 weeks, P = .49, MD = 2.15; 52 weeks, P = .32, MD = -3.08). There was a significant interaction effect between cream and BMI; therefore, the population was stratified by BMI levels (<25, <30, ≥30). The MHT groups (with exercise and education) had significantly better VISA-G outcomes (baseline, P = .04, MD = -11.20, 95% CI = -21.70 to -0.70; 12 weeks, P < .001, MD = -20.72, 95% CI = -31.22 to -10.22; 52 weeks, P = .002, MD = -16.71, 95% CI = -27.21 to -6.22) and secondary measure scores as compared with placebo at all time points when BMI was <25. CONCLUSION: MHT or placebo combined with tendon-specific or sham exercise plus education reduced pain and increased function for this population. For women with a BMI <25, MHT with any exercise plus education was better than placebo. A targeted exercise or sham exercise strategy is effective when prescribed with education about avoiding gluteal tendon compression and load management. REGISTRATION: ACTRN12614001157662 (Australian New Zealand Clinical Trials Registry).

Characterising the proximal patellar tendon attachment and its relationship to skeletal maturity in adolescent ballet dancers.

BACKGROUND: It is unknown how and when the proximal attachment of the patellar tendon matures; puberty may be key in ensuring normal tendon formation. The aim of this study was to investigate the features of the proximal patellar tendon attachment at different stages of skeletal maturity, to help gain an understanding of how and when the tendon attachment matures. METHODS: Sixty adolescent elite ballet students (ages 11-18) and eight mature adults participated. Peak height velocity (PHV) estimated skeletal maturity. Ultrasound tissue characterisation (UTC) scan was taken of the left knee and analysed for stability of echopattern. An image-based grading scale for greyscale ultrasound was developed to describe the tendon appearance. Anterior-posterior thickness was measured at the inferior pole of the patella, 1 and 2 centimetres distally. Outcomes were compared with skeletal maturity. RESULTS: Mid-portion patellar tendon thickness increased with skeletal maturity (p=0.001 at 1 cm and p=0.007 at 2 cm). There was more variance in structural appearance (greyscale classification and UTC echopattern) in pre and peri-PHV participants. Tendon attachment one-year post PHV appeared similar to mature tendons. CONCLUSIONS: Early adolescence was associated with highly variable tendon appearance, whereas the tendon appeared mature after PHV. Adolescence may be a critical time for the formation of normal tendon attachment. LEVEL OF EVIDENCE: IIb individual cohort study.

Reduced ankle dorsiflexion range may increase the risk of patellar tendon injury among volleyball players.

Patellar tendon injury, a chronic overuse injury characterised by pain during tendon loading, is common in volleyball players and may profoundly restrict their ability to compete. This cross-sectional study investigated the association between performance factors and the presence of patellar tendon injury. These performance factors (sit and reach flexibility, ankle dorsiflexion range, jump height, ankle plantarflexor strength, years of volleyball competition and activity level) were measured in 113 male and female volleyball players. Patellar tendon health was determined by measures of pain and ultrasound imaging. The association between these performance factors and patellar tendon health (normal tendon, abnormal imaging without pain, abnormal imaging with pain) was investigated using analysis of variance. Only reduced ankle dorsiflexion range was associated with patellar tendinopathy (p<0.05). As coupling between ankle dorsiflexion and eccentric contraction of the calf muscle is important in absorbing lower limb force when landing from a jump, reduced ankle dorsiflexion range may increase the risk of patellar tendinopathy.