Abstracts

152 The Impact of Extreme Loading on the Hip Joint in Ballet
S. Mayes 1 *
1
The Australian Ballet
Recurrent exposure of ballet dancers’ hips to extreme ranges of motion is believed to lead to hip osteoarthritis (OA). However, there is insufficient
evidence to support this. Hip OA is thought to involve multiple articular structures such as the articular cartilage and acetabular labrum. A causal link
between labral tear, ligamentum teres (LT) tear and early onset of hip OA has been suggested. With advances in imaging and arthroscopic techniques
there has been an increased awareness and diagnosis of these intra-articular injuries. Despite a dramatic rise in the rate of hip surgery, over the past
10 years The Australian Ballet’s medical team have successfully managed hip pain and pathology conservatively. Their philosophy of prudent
evaluation of imaging findings and thorough rehabilitation is the key to their success and lead to a hypothesis that ballet dancers are at no greater
risk of hip OA compared to other athletes and not all intra-articular pathology is symptomatic. A study was conducted to compare the prevalence of
intra-articular pathology in professional ballet dancers with age and sex-matched sporting participants and to evaluate the relationship to clinical
findings. 3T magnetic resonance imaging revealed a high prevalence of intra-articular pathology in hips. Labral tear, cartilage defects and LT tears
were the 3 most common pathologies identified, their prevalence increased with aging and they co-existed in the majority of hips. There was a high
prevalence of acetabular labral tear and cartilage defects and the frequency did not differ between professional ballet dancers and athletes. There
was a higher prevalence of LT tear in professional ballet dancers compared to the sporting population and complete and partial tears of LT were not
related to trauma or serious injury. Importantly, articular cartilage defects, labral tear and LT tear were not associated with hip pain. These findings
highlight the need for caution when interpreting MRI as not all intra-articular pathology identified with imaging is clinically relevant. This presentation
will discuss the findings of this study and the directions of future research.
153 Gluteal and tensor fascia latae muscle activity in response to isometric loading in greater trochanteric
pain syndrome
AWARD FINALIST
C. Ganderton 1 * • T. Pizzari 1 • J. Cook 2 • A. Semciw 3
1
La Trobe University • 2 Monash University • 3 The University of Queensland
Friday 23 October
Background: The use of isometric exercises in the initial stages of tendon rehabilitation is common, however, effectiveness of hip isometric
exercises in eliciting maximal gluteal muscle activity is yet to be quantified. The aim of this study was to compare the muscle activity of tensor fascia
latae muscle (TFL), gluteus medius and gluteus minimus muscle segments during three isometric hip rehabilitation exercises in symptomatic women
with greater trochanteric pain syndrome (GTPS) with matched asymptomatic women.
Methods: Intramuscular electrodes recorded electromyographic muscle activity from the anterior (GMinAnt) and posterior (GMinPost) portions of
the gluteus minimus and the anterior (GMedAnt), middle (GMedMid) and posterior (GMedPost) portions of gluteus medius muscles in 18 postmenopausal
women: ten asymptomatic (mean = 59.61 years) with no history of hip pain, injury or surgery, and eight symptomatic with a clinical
diagnosis of greater trochanteric pain syndrome and a score of