Prevalence of early hip OA features on MRI in high-impact athletes. The femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study.

OBJECTIVE: To compare early hip osteoarthritis (OA) features on magnetic resonance imaging (MRI) in high-impact athletes with and without hip and/or groin pain, and to evaluate associations between early hip OA features, the International Hip Outcome Tool (iHOT33) and Copenhagen Hip and Groin Outcome Score (HAGOS). DESIGN: This case-control study evaluated data of the femoroacetabular impingement and hip osteoarthritis cohort (FORCe). One hundred and eighty-two symptomatic (hip and/or groin pain >6 months and positive flexion-adduction-internal-rotation (FADIR) test) and 55 pain-free high-impact athletes (soccer or Australian football (AF)) without definite radiographic hip OA underwent hip MRI. The Scoring Hip Osteoarthritis with MRI (SHOMRI) method quantified and graded the severity of OA features. Each participant completed the iHOT33 and HAGOS. RESULTS: Hip and/or groin pain was associated with higher total SHOMRI (0-96) (mean difference 1.4, 95% CI: 0.7-2.2), labral score (adjusted incidence rate ratio (aIRR) 1.33, 95% CI: 1.1-1.6). Differences in prevalence of cartilage defects, labral tears and paralabral cysts between symptomatic and pain-free participants were inconclusive. There was a lower prevalence of effusion-synovitis in symptomatic participants when compared to pain-free participants (adjusted odds ratio (aOR) 0.46 (95% CI: 0.3-0.8). Early hip OA features were not associated with iHOT33 or HAGOS. CONCLUSIONS: A complex and poorly understood relationship exists between hip and/or groin pain and early hip OA features present on MRI in high-impact athletes without radiographic OA. Hip and/or groin pain was associated with higher SHOMRI and labral scores.

Getting more from standard rotator cuff strengthening exercises.

BACKGROUND: A simple modification to standard rotator cuff exercises using an additional resistance band around the scapula has been recommended in the clinical setting, postulated to encourage activation of the posterior scapular stabilisers and increase rotator cuff activation. The aim of this clinical laboratory study was to compare scapular and rotator cuff muscle activation between standard and modified exercises. METHODS: Electromyographic data were collected from 10 healthy adults via surface and intramuscular electrodes from the scapular and rotator cuff muscles. Internal and external rotation exercises of the shoulder with the arm abducted to 0°, 45° and 90° were performed using one handheld resistance band (standard) or two bands with the additional band applied to the scapula (modified). RESULTS: Activation of the trapezii and rhomboid muscles during the modified exercises at 0° and 45° of abduction was significantly greater when compared to the standard exercises (P < 0.05). No significant differences were found in rotator cuff muscle activation. DISCUSSION: Applying resistance to the posterior scapula increases activation of some scapular stabilising muscles particularly in lower ranges of abduction. This study provides preliminary evidence that this simple modification can elicit greater scapular muscle activity, potentially producing enhanced exercise outcomes with minimal additional effort.

Between session reliability of intramuscular electromyography for segments of gluteus medius and minimus during gait and stepping tasks.

Between-session reliability of electromyographic data is important for confidence in interpreting the role of muscles in functional tasks but critical if these data are to be compared before and after an intervention that seeks to change pathological patterns of muscle activity. The gluteus medius (GMed) and minimus (GMin) are known to have functionally discrete segments that are highly active during stance phase of gait and stepping tasks. This study measured the between-session reliability of activity patterns, mean amplitudes and time to peak (TTP) activity of these muscle segments. Intramuscular electrodes were placed in 3 segments of GMed and 2 segments of GMin in 10 healthy young adults for each of two testing sessions held two weeks apart. Participants completed six repetitions of comfortable speed walking trials, step-up and step-down tasks with activity patterns for each muscle segment time- and amplitude-normalized and averaged across trials. Re-test reliability for was high for activity patterns (coefficient of mean correlation ranging from 0.890 to 0.998) across all tasks and muscle segments and only two pairwise comparisons showing differences in amplitude between sessions. With standardized data collection and analysis procedures, GMed and GMin muscle segment activity patterns show good between-session reliability for weightbearing tasks.

Health professionals and students encounter multi-level barriers to implementing high-value osteoarthritis care: a multi-national study.

OBJECTIVE: Consistent evidence-practice gaps in osteoarthritis (OA) care are observed in primary care settings globally. Building workforce capacity to deliver high-value care requires a contemporary understanding of barriers to care delivery. We aimed to explore barriers to OA care delivery among clinicians and students. DESIGN: A cross-sectional, multinational study sampling clinicians (physiotherapists, primary care nurses, general practitioners (GPs), GP registrars; total possible denominator: n = 119,735) and final-year physiotherapy and medical students (denominator: n = 2,215) across Australia, New Zealand and Canada. Respondents answered a survey, aligned to contemporary implementation science domains, which measured barriers to OA care using categorical and free-text responses. RESULTS: 1886 clinicians and 1611 students responded. Items within the domains 'health system' and 'patient-related factors' represented the most applicable barriers experienced by clinicians (25-42% and 20-36%, respectively), whereas for students, 'knowledge and skills' and 'patient-related factors' (16-24% and 19-28%, respectively) were the most applicable domains. Meta-synthesis of qualitative data highlighted skills gaps in specific components of OA care (tailoring exercise, nutritional/overweight management and supporting positive behaviour change); assessment, measurement and monitoring; tailoring care; managing case complexity; and translating knowledge to practice (especially among students). Other barriers included general infrastructure limitations (particularly related to community facilities); patient-related factors (e.g., beliefs and compliance); workforce-related factors such as inconsistent care and a general knowledge gap in high-value care; and system and service-level factors relating to financing and time pressures, respectively. CONCLUSIONS: Clinicians and students encounter barriers to delivery of high-value OA care in clinical practice/training (micro-level); within service environments (meso-level); and within the health system (macro-level).

The acute effect of match play on hamstring strength and lower limb flexibility in elite youth football players.

The aim of this study was to investigate the effect of competitive football match play on hamstring strength and lower limb flexibility. Fifteen male international youth football players were included. Hamstring strength and associated pain ratings, ankle dorsiflexion, hip extension, knee extension and flexion range of motion were evaluated immediately post-match and at intervals of 24, 48, and 72 h post-match. Strength significantly reduced post-match (P < 0.01), mean difference -0.43 (CI95 : -0.56, -0.30) and 24 h post (P < 0.05) mean difference -0.12 Nm/kg (CI95 : -0.20, -0.04). The associated pain scores significantly increased at the post-match (P < 0.01, ES = 0.61) and 24 h (P < 0.01, ES = 0.55) time intervals. At the 48 and 72 h post-match tests no significant difference was found for strength or pain ratings. No significant differences were detected for any of the range of motion measures. Competitive football match play has a significant acute and transient effect on isometric hamstring strength and associated pain levels during resisted knee flexion in male international youth players. Range of motion measures appear to remain relatively unaffected by match play. Isometric hamstring strength testing and associated pain levels might be considered for inclusion in-season to monitor player's post-match hamstring recovery characteristics.

The effect of female sex hormone supplementation on tendon in pre and postmenopausal women: A systematic review.

OBJECTIVES: Oestrogen deprivation has been shown to have a negative effect on connective tissue and its turnover. A link may exist between supplemental oestrogen, preservation of tendon collagen and less tendon abnormality. The aim was to determine the effects of female sex hormone supplementation (FSHS) on tendon. METHODS: A systematic search of nine key health databases; Medline, CINAHL, EMBASE, SPORTDiscus, AUSPORT and AMI, Cochrane Library, SafetyLit and PEDro was completed (to Feb 24, 2016). The search yielded 6378 records using terms relating to hormone (oestrogen, estrogen, hormone replacement therapy, HRT, estrogen therapy, oestrogen therapy, oral contraceptive pill) and tendon. Quality assessment, data extraction and data synthesis of included papers was undertaken. RESULTS: Low level of evidence for all outcomes; no positive or negative link between FSHS and molecular, mechanical and morphological tendon response outcomes, and the addition of exercise to FSHS, had minimal effects on tendon CSA. CONCLUSIONS: The effect of oestrogen supplementation on tendon is contradictory and inconsistent. This review suggests there is a need for further studies to understand the effects of FSHS on tendon tissue at a mechanical, morphological and molecular level.

Hip abductor muscle volume in hip osteoarthritis and matched controls.

OBJECTIVE: Hip abductor muscle strength and function is negatively impacted by the presence of hip osteoarthritis (OA). This study aimed to quantify differences in hip abductor muscle volume, fatty infiltration and strength in a unilateral hip OA population when compared to a control group. Impact of radiographic severity of OA on these variables was also examined. METHODS: Volumes of gluteus maximus (GMax), medius (GMed) minimus (GMin) and tensor fascia lata (TFL) was measured using MRI and muscle volume asymmetry between limbs was calculated. Fatty infiltrate within muscles was graded using the Goutallier classification system. Hip abduction and rotation strength was tested using a dynamometer. Differences between groups or limbs were analysed using t-tests and differences in fatty infiltration using non-parametric tests. RESULTS: A statistically significant decrease in muscle volume was identified in GMax (P < 0.01), GMed (P < 0.02) and GMin (P < 0.01) on the affected side in the OA group compared to both the contralateral side and the control group and differences were related to severity of OA. Hip abduction and internal rotation strength was reduced in the OA group. Increased levels of fatty infiltration were identified in the affected limbs of the OA group for GMax (P = 0.01) and GMin (P = 0.04). CONCLUSION: Gluteal muscle atrophy, increased gluteal fatty infiltration and hip strength deficits were evident in the affected hips of OA participants. Since severity of OA was related to the extent of atrophy and fatty deposits, rehabilitation programs targeting these muscles could reverse or halt the progression of these structural and functional deficits.

Efficacy of rehabilitation programs for improving muscle strength in people with hip or knee osteoarthritis: a systematic review with meta-analysis.

To analyse the effect of exercise-based rehabilitation programs for improving lower limb muscle strength in individuals with hip or knee osteoarthritis (OA). A systematic search utilizing seven databases identified randomized controlled trials (RCTs) evaluating lower limb strength outcomes of exercise-based interventions for participants with hip or knee OA. All studies were screened for eligibility and methodological quality. Quality of evidence was assessed using Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach. Data were pooled and meta-analyses performed where appropriate. Forty RCTs were included and the majority (77%) involved resistance based exercise programs. For knee OA populations, there was high quality evidence for improved knee extension (standardized mean difference (SMD) = 0.47, 95% confidence intervals (CI) 0.29, 0.66) and flexion strength (SMD = 0.74, 95% CI 0.56, 0.92) with low-intensity resistance program when compared to a control at short term (ST) follow-up. There was moderate quality evidence for a large effect favouring high-intensity resistance programs (SMD = 0.76, 95% CI 0.47, 1.06) when compared to a control. This effect was sustained at intermediate term (IT) follow-up (SMD = 0.80, 95% CI 0.44, 1.17). Few studies reported on outcomes at long term (LT) follow-up. Only one study reported on a population with hip OA. When compared to a control group, high-intensity resistance exercise demonstrated moderate quality of evidence for large and sustained improvements for knee muscle strength in knee OA patients. Further work is needed to compare different modes of exercise at a LT follow-up for knee OA patients and to address the dearth of literature evaluating exercise interventions in people with hip OA.

Verification of a standardized method for inserting intramuscular EMG electrodes into uniquely oriented segments of gluteus minimus and gluteus medius.

Guidelines for assessing the function of gluteus minimus and gluteus medius with electromyography (EMG) traditionally offer one electrode placement site per muscle. However, anatomical studies suggest that there are two uniquely oriented segments within gluteus minimus (anterior and posterior), and three within gluteus medius (anterior, middle, and posterior) with potential for independent function. Assessment of these muscles with one electrode may therefore provide only a limited account of their role. Thus, the aim of this cadaveric study was to verify guidelines for placing intramuscular electrodes into two uniquely oriented segments of gluteus minimus, and three segments of gluteus medius. The guidelines were developed with reference to anatomical reports, cadaveric observation and real-time ultrasound imaging in vivo. Five cadaveric gluteal regions were marked for intramuscular electrode insertions based on these guidelines. Intramuscular electrodes were inserted into the marked regions of gluteus minimus (2×) and gluteus medius (3×) with the aid of a 15 cm biopsy needle. Systematic dissection revealed that electrodes were successfully inserted into uniquely oriented segments of gluteus minimus and medius. The orientation of fascicles surrounding each electrode was also consistent with segmental descriptions in past anatomical research. The findings of this research suggest that the guidelines described may be used to assess the functional role of segments within gluteus minimus and medius in health and dysfunction using EMG. Finally, electromyographers intent on investigating the role of posterior gluteus minimus must be cautious of the superior gluteal neurovascular bundle.

Onset of sexual maturity in female chickens is genetically linked to loci associated with fecundity and a sexual ornament.

Onset of sexual maturation is a trait of extreme importance both evolutionarily and economically. Unsurprisingly therefore, domestication has acted to reduce the time to sexual maturation in a variety of animals, including the chicken. In comparison with wild progenitor chickens [the Red Junglefowl (RJF)], domestic layer hens attain maturity approximately 20% earlier. In addition, domestic layers also possess larger combs (a sexual ornament), produce more eggs and have denser bones. A large quantitative trait loci (QTL) analysis (n=377) was performed using an F(2) intercross between a White Leghorn layer breed and a RJF population, with onset of sexual maturity measured and mapped to three separate loci. This cross has already been analysed for comb mass, egg production and bone allocation. Onset of sexual maturity significantly correlated with comb mass, whilst the genetic architecture for sexual maturity and comb mass overlapped at all three loci. For two of these loci, the QTL for sexual maturity and comb mass were statistically indistinguishable from pleiotropy, suggesting that the alleles that increase comb mass also decrease onset of sexual maturity.

Thoracic outlet syndrome part 2: conservative management of thoracic outlet.

Thoracic outlet syndrome (TOS) is a symptom complex attributed to compression of the nerves and vessels as they exit the thoracic outlet. Classified into several sub-types, conservative management is generally recommended as the first stage treatment in favor of surgical intervention. In cases where postural deviations contribute substantially to compression of the thoracic outlet, the rehabilitation approach outlined in this masterclass will provide the clinician with appropriate management strategies to help decompress the outlet. The main component of the rehabilitation program is the graded restoration of scapula control, movement, and positioning at rest and through movement. Adjunctive strategies include restoration of humeral head control, isolated strengthening of weak shoulder muscles, taping, and other manual therapy techniques. The rehabilitation outlined in this paper also serves as a model for the management of any shoulder condition where scapula dysfunction is a major contributing factor.

Thoracic outlet syndrome part 1: clinical manifestations, differentiation and treatment pathways.

Thoracic outlet syndrome (TOS) is a challenging condition to diagnose correctly and manage appropriately. This is the result of a number of factors including the multifaceted contribution to the syndrome, the limitations of current clinical diagnostic tests, the insufficient recognition of the sub-types of TOS and the dearth of research into the optimal treatment approach. This masterclass identifies the subtypes of TOS, highlights the possible factors that contribute to the condition and outlines the clinical examination required to diagnose the presence of TOS.

Single locus typing of MHC class I and class II B loci in a population of red jungle fowl.

In species with duplicated major histocompatibility complex (MHC) genes, estimates of genetic variation often rely on multilocus measures of diversity. It is possible that such measures might not always detect more detailed patterns of selection at individual loci. Here, we describe a method that allows us to investigate classical MHC diversity in red jungle fowl (Gallus gallus), the wild ancestor of the domestic chicken, using a single locus approach. This is possible due to the well-characterised gene organisation of the 'minimal essential' MHC (BF/BL region) of the domestic chicken, which comprises two differentially expressed duplicated class I (BF) and two class II B (BLB) genes. Using a combination of reference strand-mediated conformation analysis, cloning and sequencing, we identify nine BF and ten BLB alleles in a captive population of jungle fowl. We show that six BF and five BLB alleles are from the more highly expressed locus of each gene, BF2 and BLB2, respectively. An excess of non-synonymous substitutions across the jungle fowl BF/BL region suggests that diversifying selection has acted on this population. Importantly, single locus screening reveals that the strength of selection is greatest on the highly expressed BF2 locus. This is the first time that a population of red jungle fowl has been typed at the MHC region, laying the basis for further research into the underlying processes acting to maintain MHC diversity in this and other species.

Nontransitivity of paternity in a bird.

In many animals reproductive success is determined after insemination by the interaction of male and female processes. While sperm competition is reasonably well understood in some taxa, other processes, such as cryptic female choice and differential early embryo mortality resulting from genetic incompatibilities, are less well understood. The relative importance of these different factors contributing to reproductive success is difficult to assess. Here we control for male-mediated effects (which are often considerable and can mask more subtle processes) through the artificial insemination of known numbers of sperm in the domestic fowl to reveal that male reproductive success is nontransitive across females: the success of a particular male depends on the background against which his sperm compete for fertilization. Two potential processes could account for this effect: cryptic female choice (sperm choice) or differential early embryo mortality. Regardless of the mechanism, nontransitivity of male reproductive success has important evolutionary consequences, including the maintenance of variation in male fitness.

Effect of physiotherapy attendance on outcome after anterior cruciate ligament reconstruction: a pilot study.

BACKGROUND: In many centres patients are routinely referred for physiotherapy after anterior cruciate ligament (ACL) reconstruction. However, to date the role and amount of supervised physiotherapy required has not been clearly established. OBJECTIVE: To establish whether there was any difference in outcome between a group of patients who attended physiotherapy regularly after ACL reconstruction and a group who attended only infrequently. METHODS: Ten patients who had attended physiotherapy infrequently (mean 1.9 visits) during the first six months after ACL reconstructive surgery were matched for age, sex, graft type, and activity level and occupation before injury with 10 patients who had attended physiotherapy regularly (mean 26.5 visits). Outcome was assessed at 12 months using the Cincinnati knee rating system and the IKDC form. RESULTS: Compared with the regular physiotherapy group, patients in the minimal physiotherapy group had fewer symptoms (mean Cincinnati symptom score 46.2 v 43.4, p = 0.045). There was also a trend towards higher overall Cincinnati knee scores in the minimal physiotherapy group (mean 93.7 v 87.3, p = 0.06) but no difference in IKDC ratings. CONCLUSION: These preliminary results indicate that some patients who choose to attend physiotherapy on a very limited basis after ACL reconstruction can achieve satisfactory, if not better, outcomes than patients who attend physiotherapy regularly.

The sexually-selected sperm hypothesis: sex-biased inheritance and sexual antagonism.

When females are inseminated by more than one male (polyandry) sexual selection continues after insemination in the form of sperm competition and cryptic female choice. The sexually-selected sperm hypothesis proposes that, under the risk of sperm competition, additive variation in male traits determining fertilising efficiency will select for female propensity to be polyandrous in order to increase the probability of producing sons with superior fertilising efficiency. Two factors complicate this prediction: sex-biased transmission of male fertilising efficiency traits and sexual antagonism of sex-limited traits, fostered by sex-biased inheritance. Here, we (i) review the evidence that male traits contributing towards fertilising efficiency are heritable through sex-biased mechanisms, and (ii) explore the evolutionary implications for male and female reproductive strategies caused by both sex-biased transmission and sexual antagonism of fertilising efficiency traits. Many male fertilising efficiency traits are heritable through sex-biased mechanisms and may not necessarily increase female fitness. The predictions of the sexually-selected sperm hypothesis change dramatically under these different mechanisms of inheritance of fertilising efficiency traits, and different fitness pay-offs derived by females from the expression of such traits. Both sex-biased control of fertilising efficiency and sexual antagonism may also be important in explaining the maintenance of the genetic variance and selection potential of fertilising efficiency. We propose that a useful approach to test the sexually-selected sperm hypothesis is to combine studies which identify behavioural and physiological mechanisms explaining variation in reproductive success with artificial selection experiments to infer the underlying evolutionary patterns.

Pre- and post-insemination episodes of sexual selection in the fowl, Gallus g. domesticus.

Although much attention has been recently directed to sexual selection arising after insemination from sexual promiscuity, little is known about the mechanisms determining reproductive success after insemination, and the way these mechanisms interact with each other and with selective mechanisms occurring before insemination: mate choice and mate acquisition. Here, we briefly review the findings of an on-going study investigating the mechanisms generating variation in reproductive success at both a pre- and a post-insemination stage in the domestic fowl. Female preference consistently favours socially dominant males before and after insemination. However, although social status mediates the number of sperm that a male inseminates into a female, dominant males may inseminate sperm of lower fertilising quality than their subordinates. We argue that mitochondrial genes may contribute to determine sperm quality, and speculate that the maternal control of mitochondrial genes may prevent sexual selection from operating on males, thus explaining both the lack of a positive correlation between social dominance and sperm quality and the maintenance of variation in male quality in the fowl.

Indirect partner choice through manipulation of male behaviour by female fowl, Gallus gallus domesticus.

The direct and indirect consequences of female copulatory behaviour for copulation success have seldom been quantified. In feral fowl, most copulations were forced by males and copulation success was determined by two factors. First, female differential resistance and solicitation directly affected copulation success and were displayed non-randomly with respect to male social status. Second, another female copulatory behaviour, the distress call, had an indirect effect on both copulation success and the quality of copulation partners. Distress calls triggered male attention to a copulation, which increased the probability of higher-ranking males than the copulating male disrupting the copulation and inseminating the calling female. Females preferentially uttered distress calls when mounted by low-ranking males. Both copulation resistance and distress calling influenced copulation success, but only distress calling increased the probability of copulation disruption by other males. Consistent with the effect of direct selection, differential distress calling indirectly biased copulation success in favour of dominant males. Female fowl may thus ameliorate the effect of male sexual coercion by manipulating male behaviour.

Female feral fowl eject sperm of subdominant males.

Paternity is often determined by competition between the ejaculates of different males. Males can also use particular behaviours or structures to manipulate how females use sperm. However, the ability of females to bias sperm utilization in favour of preferred males independently of male manipulation has not been demonstrated. Females are predicted to respond differentially to the sperm of different males when the reproductive interests of the sexes differ and when females are coerced into copulating. Here we show that in female feral fowl most copulations are coerced, and that females consistently bias sperm retention in favour of the preferred male phenotype. Females prefer to copulate with dominant males, but when sexually coerced by subordinate males, they manipulate the behaviour of dominant males to reduce the likelihood of insemination. If this fails, females differentially eject ejaculates according to male status in the absence of any male manipulation and preferentially retain the sperm of dominant males.

Measurement of anterior-to-posterior translation of the glenohumeral joint using the KT-1000.

STUDY DESIGN: Single-group repeated measures. OBJECTIVES: To adapt an existing arthrometer to allow simple quantification of glenohumeral translation and to assess the arthrometer's reliability. BACKGROUND: The measurement of glenohumeral translation is an integral part of the clinical examination of the shoulder. However, no objective and reliable measure for glenohumeral translation has been reported. METHODS AND MEASURES: The KT-1000 Knee Ligament Arthrometer was used to measure the amount of anterior-to-posterior (AP) translation of the humeral head at the glenohumeral joints of 28 (16 women and 12 men) nonimpaired undergraduate university students (age 22.1 +/- 2.9 years). Two assessments were made (20 minutes apart), by a single tester, of the dominant and nondominant shoulders of each participant. RESULTS: Anterior-to-posterior translation varied from 10 to 32 mm (20.9 +/- 4.9). The test-retest reliability of the KT-1000 when measuring the nondominant shoulders was good (ICC [intraclass correlation coefficient] 0.76), and it was moderate (ICC = 0.67) when measuring the dominant shoulders. The reliability findings were influenced by large amounts of random error. Analysis by ANOVA showed that compared to women (dominant shoulder, 22.6 +/- 4.6 mm; nondominant, 23.8 +/- 4.2 mm), men showed significantly less glenohumeral translation (dominant, 17.1 +/- 3.7 mm; nondominant, 18.3 +/- 3.7 mm). CONCLUSIONS: The KT-1000 arthrometer has the potential to provide therapists with a clinically viable method of measuring glenohumeral translation.