The quantification of joint laxity in dancers and gymnasts

Patellofemoral pain and musculoskeletal features in young pre- and post-pubertal female dancers

The aim of this study was to examine associations between patellofemoral pain (PFP) and musculoskeletal features (such as tendon structure and bone properties) in young (pre- and post-pubertal) female dancers. A total of 49 dancers participated in this study (mean age 13.6 ± 2.9; weight 47.0 ± 13.2; height 153.7 ± 12.9 and body mass index (BMI) 19.4 ± 3.1) and were assessed for the following factors: dance background and Tanner stage through interviews; ultrasonography assessments of bone properties and patellar tendon structure through ultrasonographic tissue characterization and quantitative ultrasound, respectively; and anthropometric measurements, muscle strength, range of motion (ROM), hypermobility and PFP through physical examinations. PFP was found in 49% of the participants. Post-pubertal dancers with no-PFP were found to have greater muscle strength, greater radial and tibial properties, and better tendon structure compared to pre-pubertal dancers with PFP and compared to pre-pubertal dancers with no-PFP [F(2, 41) = 18.64, p < .001; F(2, 41) = 20.46, p < .001; F(2, 41) = 33.06, p < .001; and, F(2, 41) = 6.02, p = .007, respectively]. Logistic regression showed that tibial bone properties and range of movement (ROM) in hip external rotation were significantly associated with PFP [odds ratio (OR) = .889 and OR = 2.653, respectively; Cox & Snell R2 = .701]. The study revealed a high prevalence of PFP among young dancers, with low bone properties and hyperjoint ROM emerging as the main factors that are related to PFP. These findings should be addressed by medical teams, athletic trainers, and dance teachers regarding the need for implementing modifications to dance training programmes and injury-prevention strategies in young pre-pubertal dancers.

Description of ROM-SPORT I Battery: Keys to Assess Lower Limb Flexibility

Limited range of motion (ROM) is considered one of the most important intrinsic and modifiable risk factors for the most common sports-related injuries. In addition, controlling and monitoring an athlete's ROM is a strategy to achieve optimal ROM and improve athletic performance in sports, especially those that require high ROM in the major joints. Therefore, assessing ROM (pre-participation, during a rehabilitation process, on return to play, etc.) is important not only as a method to prevent sports injuries, but also as a quantitative determinant of the potential of athletic performance. However, despite the variety of different ROM assessment methods described in the literature, there is no consensus on which methods are best suited for this goal. Recently, the ROM-SPORT I battery has been shown to have advantages over other ROM assessment methods. This tool has not yet been fully described in detail for researchers, sports professionals, and clinicians to learn. The main objective of this study is to describe the ROM-SPORT I battery tests in detail using the following criteria: test description, simplicity of the test procedure, low need for human and material resources, predictive validity, and reliability.

Genetic polymorphisms related to muscular strength and flexibility are associated with artistic gymnastic performance in the Japanese population

This study aimed to examine how genetic polymorphisms related to muscular strength and flexibility influence artistic gymnastic performance in an attempt to identify a novel polymorphism associated with flexibility. In study 1, the passive straight-leg-raise (PSLR) score and aromatase gene CYP19A1 rs936306 polymorphism, a key enzyme for estrogen biosynthesis, were assessed in 278 individuals. In study 2, athletes (281 gymnasts and 1908 other athletes) were asked about their competition level, and gymnasts were assessed using the difficulty score (D-score) for each event. Muscular strength- (ACTN3 R577X rs1815739 and ACE I/D rs4341) and flexibility-related (ESR1 rs2234693 T/C and CYP19A1 rs936306 C/T) genetic polymorphisms were analyzed. In study 1, males with the CYP19A1 CT + TT genotype showed significantly higher PSLR scores than those with the CC genotype. In study 2, male gymnasts with the R allele of ACTN3 R577X showed a correlation with the floor, rings, vault, and total D-scores. In addition, male gymnasts with the C allele of ESR1 T/C and T allele of CYP19A1 C/T polymorphisms were correlated with the pommel horse, parallel bars, horizontal bar, and total D-scores. Furthermore, genotype scores of these three polymorphisms correlated with the total D-scores and competition levels in male gymnasts. In contrast, no such associations were observed in female gymnasts. Our findings suggest that muscular strength- and flexibility-related polymorphisms play important roles in achieving high performance in male artistic gymnastics by specifically influencing the performance of events that require muscular strength and flexibility, respectively. HighlightsEstrogen-related CYP19A1 polymorphism is a novel determinant of flexibility in males.Muscular strength- and flexibility-related polymorphisms play important roles in high performance in male artistic gymnastics.Genotypes of ACTN3 R577X, ESR1 rs2234693, and CYP19A1 rs936306 may contribute to training plan optimization and event selection in artistic gymnastics.

Joint Hypermobility Does Not Increase the Risk of Developing Hip Pain, Cartilage Defects, or Retirement in Professional Ballet Dancers Over 5 years

OBJECTIVE

This study aimed to evaluate the risk of developing hip pain, cartilage defects, and retirement in hypermobile ballet dancers over 5 years.

DESIGN

Prospective cohort study.

SETTING

Professional Ballet Company.

PARTICIPANTS

Forty ballet dancers (57.5% women) were assessed at baseline and 21 dancers at 5 years.

INDEPENDENT VARIABLE

Baseline evaluation of generalised joint hypermobility (GJH) (GJH = Beighton score ≥5/9).

OUTCOME MEASURES

Cartilage defects on hip 3T magnetic resonance imaging and pain (the Copenhagen Hip and Groin Outcome Score: HAGOS) at baseline and follow-up, hip-related injury incidence, and retirement over 5 years.

RESULTS

Twelve dancers retired by follow-up, none due to hip injury or GJH. At baseline, 17 (42.5%) dancers were hypermobile, 18 (45%) had cartilage defects, and 15 (37.5%) reported hip pain (HAGOS pain <100). Cartilage defect prevalence was lower in GJH (n = 1) than non-GJH dancers (n = 17, P < 0.001). Beighton scores <5/9 were predictive of cartilage defect presence at baseline, independent of age and sex (P = 0.006). At follow-up, cartilage defects progressed in 2 dancers, one was hypermobile. Baseline and follow-up HAGOS pain scores were similar in GJH and non-GJH dancers (P > 0.05 for all). Hip-related injury over 5 years was reported by a similar number of GJH (n = 7) and non-GJH dancers (n = 6, P = 0.7). Hypermobility was more prevalent in active dancers (n = 12) than dancers who retired (n = 2), independent of age, rank, and sex (P = 0.03).

CONCLUSIONS

Hypermobile dancers are at no greater risk of reporting hip pain and injury or retirement over 5 years, and cartilage defect prevalence was much lower in GJH than non-GJH dancers.

The Injured Shoulder in High-Level Male Gymnasts, Part 1: Epidemiology and Pathoanatomy of Surgically Treated Lesions

BACKGROUND

Weightbearing and traction-suspension movements with the upper limbs put considerable demands upon the shoulder region of high-level gymnasts. The diagnosis of instability in these gymnasts may be difficult because voluntary inferior shoulder subluxation is part of their training and is needed to perform some acrobatic figures.

PURPOSE

To (1) assess the epidemiology of shoulder lesions requiring surgery, (2) describe the types of injuries and assess which maneuvers and equipment put the gymnast most at risk, and (3) present a pathoanatomic classification of the injured shoulder in high-level male gymnasts.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Over a 20-year period (1994-2014), 26 high-level male gymnasts (30 shoulders; mean age, 22 years; range, 16-33 years) were referred to our surgical center for shoulder pain or instability. Four gymnasts underwent surgery on both shoulders. All shoulders were evaluated clinically, radiologically, and arthroscopically. An independent observer evaluated the circumstances in which these lesions occurred, including the apparatus used and the maneuvers performed.

RESULTS

The mean duration of symptoms before surgery was 8 months (range, 6-24 months). Eighteen injured shoulders (60%) had chronic overuse injuries. In 27 shoulders (90%), the mechanism of injury was traction of the arm in forced flexion-rotation while using suspension equipment with locked hands on the bars or the rings. In the remaining 3 shoulders, the traumatic position was one of an isometric muscle contraction against gravity, sustained while performing strength-and-hold positions on the rings. Based on the main presenting symptoms (pain and/or instability) and main anatomic lesions found during arthroscopy, the injured gymnasts' shoulders were classified into 2 categories: painful shoulders (n = 13) with no clinical, radiological, or arthroscopic findings of instability (mainly superior cuff and biceps anchor lesions) and unstable shoulders (n = 17) with isolated inferior capsule labral tears or mixed lesions (tendinous and capsulolabral). Some gymnasts with inferior labral tears had no recall of having suffered a dislocation or subluxation.

CONCLUSION

The majority of injuries requiring surgery in this population occurred during traction in forced flexion-rotation using suspension equipment. Injured shoulders were classified as either painful or unstable shoulders.

A Physiotherapeutic Approach to Musicians' Health - Data From 614 Patients From a Physiotherapy Clinic for Musicians (INAP/O)

Currently, the treatment of musicians is an interprofessional approach. Playing-related health complaints may impact the performance of a musician. In Germany, a medical consulting hour for musicians exists, but those for athletes in sports medicine are not so common. The diagnosing and treatment procedure within the physiotherapy consultation for musicians follows a specific concept-b and requires knowledge of instruments and musician-specific complaints. Based on the consulting hour in a clinic in Osnabrueck, 614 case reports were part of this sample, of which 558 data sets were complete. The focus of the analysis is the instrument and the primary complaint. Also, the type of therapy is characterized, and the amount is calculated. Primary complaints of musicians, in general, are found most frequently in the spine and upper extremity. Musician complaints are different between instruments. Instrumentalists have a significantly higher chance to suffer from a primary complaint in the area of the upper extremity. Furthermore, the groups without an instrument (e.g., singing or dancing) are developing complaints in the anatomical area which they primarily use. Therefore, these types of therapy were used: physiotherapy, manual therapy, and osteopathy with an average of 5.9 treatment units. This study underpinned the importance of musician-specific physiotherapy as a profession to treat musicians. Also, an interdisciplinary approach is necessary to treat all aspects of complaints.

Hip Instability in Ballet Dancers: A Narrative Review

BACKGROUND

Dancers possess a large degree of hip range of motion that results from a combination of innate and acquired osseous morphology and permissive soft tissues. Generalized hypermobility in dancers may predispose them to a spectrum of hip instability. The objective of this narrative review is to discuss the anatomical characteristics, pathogenesis, risk factors, clinical signs and symptoms, management, and outcomes of hip instability treatments in dancers.

METHODS

A retrospective search was performed beginning November 1, 2017, for English language articles regarding hip stability in the dancer. Key words used included but were not limited to: dance(r), ballet, hip, hypermobility, range of motion, instability, microinstability, and laxity. PubMed, Scopus, and MEDLINE databases were used.

RESULTS

Forty-three studies were analyzed. Groin pain was found to be the most common presenting symptom of hip instability. A variety of impingement and instability signs may be elicited during physical examination. Hypermobility is frequently observed and is thought to be a necessity for participation in elite levels of ballet. Radiographs and advanced planar imaging (magnetic resonance imaging and computed tomography) should be scrutinized to evaluate for dysplasia, cam, pincer, subspine, and rotational morphologies. Dysplasia (low volume acetabulum), cam morphology, femoral retroversion, and coxa valga are common findings in the ballet dancers' hip. Labral injuries and ligamentum teres tears are common and may potentiate instability in the hip. Management options include education, oral non-opioid medications, activity modification, exercise prescription, and surgery. Reported outcomes of these treatments in ballet are limited.

CONCLUSION

Hip hypermobility is prevalent in the ballet population and is a clear advantage. However, it may increase the risk of instability. It is important to identify the multifactorial osseous and soft tissue etiology of hip or groin pain in dancers. Practitioners should have a high level of suspicion for hip instability in the dancer presenting with hip pain and treat accordingly. There is a significant need for increased quantity and quality of investigation into the outcomes of treatment for hip instability in the dancer.

Generalized joint hypermobility, scoliosis, patellofemoral pain, and physical abilities in young dancers

Background

Many young girls with generalized joint hypermobility (GJH) choose to participate in dance because their bodies are suited for this activity. Scoliosis tends to occur often in thin girls, who also are more likely to choose dance. Both anomalies (GJH and scoliosis) may be related to reduced abilities such as diminished strength and insufficient postural balance, with increased risk for musculoskeletal conditions. The main objectives of the present study were to determine the prevalence of dancers with GJH, the prevalence of dancers with scoliosis, and the prevalence of dancers with these two anomalies; and, to determine differences in physical abilities and the presence of patellofemoral pain (PFP) between young female dancers with and without such anomalies.

Methods

One hundred thirty-two female dancers, aged 12–14 years, were assessed for anthropometric parameters, GJH, scoliosis, knee muscle strength, postural balance, proprioception ability, and PFP.

Results

GJH was identified in 54 dancers (40.9%) and scoliosis in 38 dancers (28.8%). Significant differences were found in the proportion of dancers with no anomalies (74 dancers, 56.1%) and dancers with both anomalies (34 dancers, 25.8%) (p < .001). Dancers with both anomalies had reduced dynamic postural balance in the anterior direction (p = .023), reduced proprioception ability (p < .001), and weaker knee extensors (p = .036) and flexors (p = .040) compared with dancers with no anomalies. Among dancers with both anomalies, 73.5% suffered bilateral PFP, 17.6% suffered unilateral PFP, and 8.8% had no PFP (p < .001).

Conclusions

A high prevalence of young girls participating in dance classes had GJH, as the increased joint flexibility probably provides them with some esthetic advantages. The high prevalence of scoliosis found in these young dancers might be attributed to their relatively low body mass, their delayed maturation, and the selection process of dancers. Dancers with both GJH and scoliosis had decreased muscle strength, reduced postural balance, reduced proprioception, with higher risk of PFP. The main clinical implications are the need to reduce the risk of PFP among dancers by developing appropriate strength and stabilizing exercises combined with proprioceptive and postural balance training, to improve the correct alignment of the hyperextended and hypermobile joints, and to improve their supporting muscle strength.

Assessment of the Range of Movement of the Lower Limb in Sport: Advantages of the ROM-SPORT I Battery

Range of movement (ROM) assessment is an important strategy to increase physical-technical performance and minimize the risk of sports-related injuries. Currently, there is no consensus regarding which ROM assessment method is the most appropriate. The main objective of this study was to perform a systematic review of the test batteries available for the assessment of lower limb ROM; additionally, we compare the ROM-SPORT I battery with those previously reported in the literature. The systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The identification of publications was made by using the databases SciELO, Medline, Scopus, PubMed, and Web of Science. Based on the inclusion criteria, sixteen publications were selected and analyzed. The ROM-SPORT I battery is the most valid of the analyzed methods. This battery evaluates the ROM of eleven lower limb movements. The inclinometer with a telescopic arm and a box is a simpler, more comfortable, and faster procedure than others. The Lumbosant support and use of two examiners are essential to avoid compensatory movements to obtain reliable measurements during ROM assessment. The ROM-SPORT I is a field-based battery of tests that may be used by sports professionals, clinics, and researchers in applied settings to accurately assess and monitor lower extremity ROM.

Prevalence and Impact of Chronic Ankle Instability in Adolescent Athletes

Background:

The prevalence and impact of chronic ankle instability (CAI) in adolescent athletes are unknown. To better develop and justify prevention strategies of lateral ankle sprains and CAI, it is important to understand the origin and associated long-term impact of CAI within populations other than adults.

Purpose/Hypothesis:

The purpose of this study was to determine the prevalence and impact of CAI on ankle function, health-related quality of life (HRQoL), and physical activity in adolescent athletes. The hypothesis was that the presence of CAI will be commonly reported among adolescent athletes and that participants with CAI will have lower self-reported ankle function, HRQoL, and physical activity when compared with participants without CAI.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A cohort of 1002 healthy (able to fully participate) adolescent athletes (50.4% female; mean age, 15.6 ± 1.6 years) across 8 club sport facilities and high schools completed paper-and-pencil surveys to establish the presence of CAI (Identification of Functional Ankle Instability [IdFAI]) and estimate perceived ankle function (Foot and Ankle Ability Measure [FAAM]–Activities of Daily Living and FAAM-Sport), HRQoL (Pediatric Quality of Life Inventory 4.0 [PedsQL]), and physical activity (Hospital for Special Surgery Pediatric Functional Activity Brief Scale [HSS Pedi-FABS]).

Results:

The overall prevalence of CAI was 20.0%. Participants with unilateral CAI reported significantly lower (P < .001) ankle function (FAAM-Sport: 87.0 ± 14.8) and HRQoL (total PedsQL: 89.8 ± 9.8) than participants who did not have CAI (FAAM-Sport: 97.7 ± 6.0; total PedsQL: 93.5 ± 9.1). Physical activity was not different between participants with and without CAI.

Conclusion:

The prevalence of CAI was high among adolescent athletes. The presence of CAI negatively affected ankle function and HRQoL in adolescent athletes. Given the high prevalence and negative impact of CAI in an adolescent population, strategies to prevent ankle injuries and maintain physical activity are needed to alleviate future long-term consequences associated with developing CAI. These strategies should be implemented as soon as sport participation begins, as it appears that the origin of CAI may occur before adulthood.

The relationship between the functional movement screen, star excursion balance test and the Beighton score in dancers

Objectives: To determine the association between the Functional Movement Screen (FMS), Star Excursion Balance Test (SEBT) and the Beighton Score (BS) in dancers with implications for performance and injury.Methods: The study was of cross-sectional design and included 47 female university dancers (age: 20.4 ± 0.7 years, height: 160.5 ± 5.8 cm; mass: 55.6 ± 4.8 kg). Participants completed the FMS and the anterior, posteromedial and posterolateral reach components of the SEBT and hypermobility was assessed via the BS.Results: A fair significant correlation existed between FMS composite and total BS (r = 0.37, p = 0.01). For individual elements of the screening tools, there were 24 significant correlations between the FMS and the BS, 11 significant correlations between the FMS and SEBT and 4 significant correlations between the SEBT and BS.Conclusion: The FMS and the BS correlations highlighted the importance of the deep squat in functional movement and the relationship between FMS mobility elements and the BS. The significant correlation between the FMS and the BS may suggest that they capture similar information. The active straight leg raise and shoulder mobility measurements should be considered key elements to measure during screening.

Joint Hypermobility as a Predictor of Mechanical Loading in Dancers

CONTEXT

Dance requires the performance of complex movements that may exceed normal anatomical range. However, in hypermobile individuals, this may have implications for injury and performance.

OBJECTIVES

The aim of the study was to investigate the efficacy of the Beighton score (BS) in predicting mechanical loading in dancers in hypermobile and nonhypermobile dancers with consideration of accelerometer placement and lumbar flexion hypermobility.

DESIGN

Cohort study, clinical measurement.

SETTING

University.

PARTICIPANTS

A total of 34 dancers had their joint hypermobility assessed by the BS. Participants completed the Dance Aerobic Fitness Test with a global positioning device incorporating a triaxial accelerometer located at the cervico-thoracic junction (C7) and one at the midbelly of the gastrocnemius.

MAIN OUTCOME MEASURES

Accelerometry data were used to calculate PlayerLoad total, PlayerLoad medial-lateral, PlayerLoad anterior-posterior, and PlayerLoad vertical. Physiological response was measured via heart rate and fatigue response by rate of perceived exertion.

RESULTS

The total BS was a poor predictor of all mechanical loading directions with PlayerLoad anterior-posterior C7 (r = .15) and PlayerLoad total lower limb (r = .20) the highest values. Multiple linear regression was a better predictor with values of C7 (r = .43) and lower limb (r = .37). No significant difference existed between hypermobile and nonhypermobile subjects for mechanical loading values for all stages of the Dance Aerobic Fitness Test and for heart rate and fatigue responses.

CONCLUSIONS

The BS is not a good predictor of mechanical loading which is similar in hypermobile and nonhypermobile dancers for all levels of the Dance Aerobic Fitness Test. Mechanical loading and fatigue responses are similar between hypermobile and nonhypermobile dancers.

The Beighton Score and Injury in Dancers: A Prospective Cohort Study

CONTEXT

Joint hypermobility has a high prevalence in dancers and may be associated with injury and performance.

OBJECTIVES

To investigate whether total Beighton score can predict injury and to determine the relationship between joint hypermobility and injury, and to report injury demographics.

DESIGN

A prospective cohort injury study.

SETTING

Edge Hill University dance injury clinic.

PARTICIPANTS

Eighty-two dancers (62 females, 20 males).

MAIN OUTCOME MEASURES

Joint hypermobility via the Beighton score ≥4 with lumbar flexion included and removed.

RESULTS

A total of 61 dancers were classified as hypermobile, which was reduced to 50 dancers with lumbar flexion removed. A significant difference existed between pooled total days injured in hypermobile dancers and nonhypermobile dancers with lumbar flexion included (P = .02) and removed (P = .03). No significant differences existed for total Beighton score between injured and noninjured groups with lumbar flexion included (P = .11) and removed (P = .13). Total Beighton score was a weak predictor of total days injured (r2 = .06, P = .51). In total, 47 injuries occurred in 34 dancers, and pooled injury rate was 1.03 injuries/1000 hours. Receiver operating characteristic curve analysis demonstrated an area under the curve of 0.83 for male dancers with lumbar flexion removed, which was considered diagnostic for injury.

CONCLUSIONS

The Beighton score can be utilized to identify dancers who may develop injury. Clinicians should consider the role of lumbar flexion in total Beighton score when identifying those dancers at risk of injury. Different injury thresholds in female and male dancers may aid injury management.

Beighton scoring of joint laxity and injury incidence in Middle Eastern male youth athletes: a cohort study

Objectives

To examine the association between generalised joint laxity (GJL) and injury rates in Middle Eastern male youth athletes.

Design

Prospective observational study consisting of GJL screen and injury audit (season 2009/2010).

Setting

Aspire Sports Academy Doha, Qatar.

Participants

A total of 226 adolescent male athletes (mean age: 14.2 years; SD: 1.7; range: 10–18) involved in 15 sporting activities were grouped into contact and non-contact sports. All available athletes were included in this study.

Outcome measures

A seasonal injury audit, athletes’ anthropometric characteristics, for example, weight, height and body mass index and screen for GJL to determine Beighton Score (BS).

Results

The 226 athletes sustained 596 injuries and 75% reported at least one injury over a seasonal injury audit. Players in contact sports were injured more often than players in non-contact sports (more frequent injuries than injury-free time in contact sports; 127 days (95% CI 93 to 160) vs 176 days in non-contact sports (95% CI 118 to 234) (p<0.001). Survival analysis showed that gradient BS was not associated with injury HR=1.004 (95% CI 0.95 to 1.06) in the overall cohort. However, BS was associated with a greater injury risk in contact sports (HR: 1.29; 95% CI 1.05 to 1.59; p=0.015).

Conclusion

Greater GJL, defined by gradient BS, plus involvement in contact sports together influence injury risk in youth athletes. Preseason documentation of GJL scoring should be considered specifically for contact sports as injury pre-emptive measure.

Pediatric and adolescent ankle instability: diagnosis and treatment options

PURPOSE OF REVIEW

The purpose of this review is to discuss the epidemiology, pathoanatomy, diagnosis, and treatment for lateral ankle instability in pediatric patients.

RECENT FINDINGS

Chronic ankle instability is a common sequela of lateral ankle sprain in young athletes. Incidence is increasing, possibly due in part to inadequate treatment of first-time ankle sprains, as well as increased youth participation in organized and competitive sports. The anterior talofibular ligament (ATFL) is injured in every case, whereas the calcaneofibular ligament (CFL) and syndesmosis may be involved in severe cases. A clinical history, focused physical exam, and appropriate radiographic studies aid in diagnosis, and predisposing factors must be identified. Early treatment of ankle sprains involves bracing or immobilization, followed by a course of physical therapy. Surgery involves anatomic repair of the torn ligaments, and may be required in cases of severe functional and mechanical instability with recurrent sprains refractory to nonsurgical management. Intraarticular disorders should be identified and may be addressed with ankle arthroscopy.

SUMMARY

Prompt treatment of lateral ankle instability in young athletes is important to prevent chronic ankle instability. Many patients are successfully treated without surgery, and those requiring operative intervention improve function postoperatively.

The Physical Attributes Most Required in Professional Ballet: A Delphi Study

Background It is commonly accepted that dancers are undoubtedly athletes, with ballet perhaps the most demanding dance form. No previous study has sought to define the physical attributes most desired for classical ballet by professional companies and vocational schools. These are likely to include both aesthetic features and attributes that reduce the risk of injury as well as enhance performance. Method An initial survey question using the modified Delphi technique was sent using Opinio Survey Software to a selected international expert panel. This was drawn both from those involved in selection of elite professional ballet dancers, and the international medical professionals involved in the care of dancers. The first questionnaire was open-ended to scope for all the physical attributes most favoured by the professional experts. Results There were 148 responses from the panel of international experts. In total 34 physical attributes were suggested. The 2 most recommended physical criteria for selection into the profession were overall flexibility and overall strength. These results are discussed in the context of the published literature on the mechanics, anatomy and physiology of ballet. Conclusion Flexibility and strength are the 2 features most sought after in elite ballet dancers.

Classifying joint hypermobility: a comparison of three current classification systems

Background/Aims:

Joint hypermobility is an excessive range of motion in one joint and is related to increased risk of injury and performance adaptations within sports and dance. Joint hypermobility classification lacks consistency across the literature, which may hinder effective management. The aim of the study was to compare the prevalence of joint hypermobility across sex- and sport-specific participation using three different classification systems.

Methods:

Joint hypermobility was assessed in 286 participants consisting of rugby players, netballers, dancers and female and male controls. The Beighton score was used to measure joint hypermobility in the fifth metacarpophalangeal joints, thumbs, elbows, knees and lumbar spine. Scores were subsequently categorised using three different joint hypermobility classifications previously reported by Beighton et al (1973) , Boyle et al (2003) and Stewart and Burden (2004) .

Findings:

The prevalence of ‘not hypermobile’ varied considerably between classifications. This difference was greatest in female netball players and smallest in male rugby players. Within the ‘not hypermobile’ category, an additional 33 females and 5 males were ‘not hypermobile’ with the Beighton et al (1973) and Stewart and Burden (2004) criteria, which may highlight a sex consideration when assessing low Beighton scores. In the ‘distinctly hypermobile’ category, female subjects demonstrated sensitivity to classification system, most prominently dancers.

Conclusions:

There may be a need for separate sex categories. The female dancer classification may require further categorisation to identify extremes of joint hypermobility more effectively, which may aid injury prevention strategies.

The Upper Limb Hypermobility Assessment Tool: A novel validated measure of adult joint mobility

BACKGROUND

Existing measures of generalized joint hypermobility do not include commonly affected upper limb joints.

OBJECTIVE

To evaluate the reliability of a novel clinically-applicable measure of upper limb joint mobility, its ability to discriminate between varying extents of hypermobility, identify generalized joint hypermobility, and to establish a cut-point for hypermobility classification.

DESIGN

Validation of a diagnostic tool.

METHOD

Participants were sought from three groups - healthy controls, likely and known hypermobiles, and assessed using the Upper Limb Hypermobility Assessment Tool (ULHAT), Beighton score and clinical opinion. Pearson's correlation coefficient examined individual group and whole cohort relationships between upper limb hypermobility, age, gender and ethnicity. MANOVA investigated between-group differences in ULHAT scores. Median interquartile ranges and ROC Curve analysis identified the cut-off score for identification of upper limb hypermobility. Percent agreement with clinical opinion assessed the ability of the ULHAT to identify generalized joint hypermobility.

RESULTS

112 adult participants (mean age 24.3 ± 5.5years) across the three groups were assessed. Inter-rater reliability of the tool was high (ICC2,1 = 0.92). The cut-point was established at ≥7/12 (sensitivity 0.84, specificity 0.77, +LR 3.7, -LR 0.2). Upper limb hypermobility did not vary with age or ethnicity (both p > 0.12), but was greater in females (p < 0.001). The ULHAT discriminated between the three groups and identified generalized hypermobility.

CONCLUSIONS

The 12-item ULHAT measures mobility of multiple upper limb joints in all movement planes. Using a cut-off of ≥7/12 in adults, the ULHAT is a reliable and valid tool for identifying upper limb hypermobility and generalized joint hypermobility.

The association between menarche, intensity of training and passive joint ROM in young pre-professional female dancers: A longitudinal follow-up study

OBJECTIVES

To determine the association between the status of menarche (yes/no), the intensity of training and the potential to improve passive joint range of motion (ROM) over a 12-month period of dance training.

DESIGN

Prospective cohort study.

SETTING

Dance studio.

PARTICIPANTS

Fifty-nine female dancers aged 12.8 ± 0.5.

MAIN OUTCOME MEASURES

The dancers were asked about their dance intensity and screened for anthropometric parameters and passive joint ROM in Grades 7 and 8.

RESULTS

Along the 12 months of dance training, we found significantly increased ankle-foot en-pointe, hip abduction, and hip external rotation (ER); significantly decreased hip internal rotation (IR); and significant increased hip ER:IR ratio. In Grade 7, 26 dancers (44.1%) reached menarche (Yes menarche); in Grade 8 an additional 23 dancers (39.0%) reached menarche (No/Yes menarche); and 10 dancers (16.9%) had not reached menarche (No menarche). MANOVA (mixed models) with repeated measures to compare joint ROM between the three menarche groups (Yes; No/Yes; No), with h/week dance practice as a co-variant, showed that hip ER, ankle-foot en-pointe, and ER:IR were significantly correlated with h/week in all three menarche groups.

CONCLUSIONS

Most passive joint ROM can be improved over 12 months of dancing around the age onset of menarche. H/week of dance practice is a main factor contributing to improved hip ER, ankle-foot en-pointe and ER/IR ratio.

The Beighton score as a predictor of Brighton criteria in sport and dance

OBJECTIVES

To determine the efficacy of using the Beighton joint hypermobility score as a predictor of Brighton criteria components, considering the influence of gender and sports participation.

DESIGN

Cross sectional study design.

SETTING

A University.

PARTICIPANTS

Sixty-five female rugby players, 38 male rugby players, 61 netball players, 42 female dancers, 40 male controls and 40 female controls.

MAIN OUTCOME MEASURES

The Beighton score was assessed using the Beighton and Horan Joint Mobility Index. The Brighton criteria was used to assess joint hypermobility syndrome. A binary logistic regression was performed for a pooled sample (n = 286), and subsequently for gender and sport to assess the Beighton score as a predictor of Brighton criteria.

RESULTS

Beighton scores were found to be a predictor of arthralgia (P = 0.002), dislocation and subluxation (P = 0.048) in the pooled analysis; a predictor of dislocation and subluxation (P = 0.047) in males and arthralgia (P = 0.001) in females. Beighton scores were a predictor of arthralgia in female rugby (P = 0.003) and in female controls (P = 0.012).

CONCLUSIONS

The potential of the Beighton score to predict joint arthralgia and dislocation/subluxation may allow clinicians to implement effective injury prevention strategies.

Effects of Latin style professional dance on the spinal posture and pelvic tilt

BACKGROUND

Systematic repetition postures adopted during trainings could generate alterations in the sagittal spinal curvatures.

OBJECTIVE

The purposes were: 1) to analyse the sagittal spinal curvatures and pelvic tilt in Latin American style dancers; 2) to compare the spinal sagittal mobility and hamstring muscle extensibility between Latin American style dancers and non-dancers; and 3) to evaluate the influence of wearing dance shoes upon the sagittal spine posture in standing.

METHODS

A total of 20 Latin American style professional dancers and 20 non-dancers (control group) were evaluated during standing, relaxed sitting, maximal trunk flexion with knees flexed and extended, lying prone, and maximal trunk extension. Additionally, dancers were analysed while standing barefoot, and wearing heeled-shoes, during forward walking and the paso-doble posture. The hamstring muscle extensibility was evaluated by the active knee extension test.

RESULTS

The spinal morphology in Latin American style professional dancers is characterised by lower thoracic kyphosis, lumbar lordosis and anterior pelvic tilt in the standing posture as well as a flexible spine, especially in flexion postures, in addition to suitable hamstring muscle extensibility.

CONCLUSIONS

The spinal morphology of Latin American style professional dancers is characterised by lower thoracic kyphosis and lumbar lordosis and anterior pelvic tilt in the standing posture as well as a flexible spine, especially in flexion postures, and suitable hamstring muscle extensibility.

Risk factors for musculoskeletal injury in elite pre-professional modern dancers: A prospective cohort prognostic study

OBJECTIVES

To examine risk factors for injury in pre-professional modern dancers.

DESIGN

With prospectively designed screening and injury surveillance, we evaluated four risk factors as categorical predictors of injury: i) hypermobility; ii) dance technique motor-control; iii) muscle tightness; iv) previous injury. Screening and injury data of 180 students enrolled in a university modern dance program were reviewed over 4-yrs of training. Dancers were divided into 3-groups based on predictor scores. Dance exposure was based on hours of technique classes/wk. Negative binomial log-linear analyses were conducted with the four predictors, p < 0.05.

RESULTS

Dancers with low and high Beighton scores were 1.43 and 1.22 times more likely to sustain injury than dancers with mid-range scores (p ≤ 0.03). Dancers with better technique (low or medium scores) were 0.86 and 0.63 times less likely to sustain injury (p = 0.013 and p < 0.001) compared to those with poor technique. Dancers with one or 2-4 tight muscles were 2.7 and 4.0 times more likely to sustain injury (p ≤ 0.046). Dancers who sustained 2-4 injuries in the previous year were 1.38 times more likely to sustain subsequent injury (p < 0.001).

CONCLUSIONS

This contributes new information on the value of preseason screening. Dancers with these risk factors may benefit from prevention programs.

The prevalence of generalized and syndromic hypermobility in elite Australian dancers

OBJECTIVES

To determine the prevalence of Generalized Joint Hypermobility (GJH) and Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome-Hypermobility Type (JHS/EDS-HT) among dancers using established validated measures.

DESIGN

Observational Cohort Study.

SETTING

Laboratory.

PARTICIPANTS

85 dancers from two dance institutions.

MAIN OUTCOME MEASURES

GJH was determined using the Beighton score (cut-point ≥5/9) and the Lower Limb Assessment Scale (LLAS) (cut-point ≥7/12). Presence of JHS/EDS-HT was assessed using the Brighton and Villefranche criteria. Paired sample t-test was performed to compare LLAS side-to-side scores, and percentage disagreements calculated to determine differences between the two GJH and the two JHS/EDS-HT measures.

RESULTS

72% of dancers met the Beighton cut-point for GJH, while 38% and 42% met the LLAS cut-point on the left and right respectively. The proportion of dancers identified with GJH was different when assessed using the Beighton compared to the left and right LLAS (both p < 0.001), a disagreement of 48% and 46% respectively, with Beighton classifying more participants as having GJH. The Villefranche identified more dancers with JHS/EDS-HT than the Brighton (84% vs 31%, p < 0.001), with 54% disagreement.

CONCLUSIONS

High prevalence of generalized and syndromic hypermobility was found regardless of the criteria used. A higher Beighton cut-point, e.g. ≥6/9, to identify true GJH amongst dancers maybe warranted.

Identifying lower limb specific and generalised joint hypermobility in adults: validation of the Lower Limb Assessment Score

BACKGROUND

The Lower Limb Assessment Score (LLAS) has only been validated in a paediatric population. The aim of this study was to validate the use of the LLAS in an adult population by: i) evaluating its ability to discriminate between different extents of lower limb hypermobility, ii) establishing a cut-off score to identify lower limb hypermobility, and iii) determining if the LLAS is able to identify Generalised Joint Hypermobility (GJH).

METHODS

Participants were recruited across three groups representing varying degrees of hypermobility. They were assessed using the LLAS, Beighton score and clinical opinion. Pearson's correlation coefficient and MANOVA were used to assess between-group differences in the LLAS. The cut-off score was determined using median and inter-quartile ranges and the Receiver Operator Characteristic Curve. The ability of the LLAS to identify GJH was assessed using percent agreement with clinical opinion.

RESULTS

One hundred twelve participants aged 18-40 years were recruited. The LLAS distinguished the control from the likely hypermobile and known hypermobile cohorts (both p < 0.001), as well as the likely hypermobile from the known hypermobile cohort (p = 0.003). The LLAS cut-off score for identifying lower limb hypermobility was ≥7/12 with a specificity of 86% and sensitivity of 68%. The LLAS accurately identified those with GJH with high percentage agreement compared to clinical opinion across all cohorts (69-98%).

CONCLUSIONS

The LLAS is a valid tool for identifying lower limb specific hypermobility and GJH in adults at a cut-off score of ≥7/12. It demonstrates excellent specificity and moderate sensitivity, and discriminates well between extents of hypermobility.

Upper Extremity Injuries in Gymnasts

Gymnastics is a unique sport, which loads the wrist and arms as weight-bearing extremities. Because of the load demands on the wrist in particular, stress fractures, physeal injury, and overuse syndromes may be observed. This spectrum of injury has been termed "gymnast's wrist," and incorporates such disorders as wrist capsulitis, ligamentous tears, triangular fibrocartilage complex tears, chondromalacia of the carpus, stress fractures, distal radius physeal arrest, and grip lock injury.

Postural balance control in women with generalized joint laxity

Objectives

This study aims to investigate the potential relationship between joint laxity and postural balance by using tetra-ataxiometric posturography (Tetrax®).

Patients and methods

A total of 69 healthy volunteers were included in the study and classified into three groups based on their hypermobility severity determined with Beighton-Horan hypermobility index scores. Of those, 29 participants were non-hypermobile, 13 participants were mildly hypermobile and remaining 27 patients had severe hypermobility. Postural control of the participants was evaluated by using the Tetrax® device in eight different positions. The stability index, Fourier index, weight distribution index, and synchronization index scores of each participant were recorded.

Results

We found that the participants with severe hypermobility exhibited significantly higher stability index scores while the position of the head is extended and rotated right. The weight distribution index on elastic surfaces was impaired in non-hypermobile and severely hypermobile participants. We observed that the Fourier Index scores were higher at a higher-medium frequency (0.5-1 Hz) in participants with severe hypermobility. There was no difference between the groups in terms of synchronization index scores.

Conclusion

These findings suggest that severely hypermobile individuals have a decreased postural stability in head-extended and head- rotated positions when compared to individuals who are non-hypermobile. This increased instability may lead to an increased risk of musculoskeletal injuries, especially in sports that require extension and rotation movements of the head.

Stretching the Spines of Gymnasts: A Review

Gymnastics is noted for involving highly specialized strength, power, agility and flexibility. Flexibility is perhaps the single greatest discriminator of gymnastics from other sports. The extreme ranges of motion achieved by gymnasts require long periods of training, often occupying more than a decade. Gymnasts also start training at an early age (particularly female gymnasts), and the effect of gymnastics training on these young athletes is poorly understood. One of the concerns of many gymnastics professionals is the training of the spine in hyperextension-the ubiquitous 'arch' seen in many gymnastics positions and movements. Training in spine hyperextension usually begins in early childhood through performance of a skill known as a back-bend. Does practising a back-bend and other hyperextension exercises harm young gymnasts? Current information on spine stretching among gymnasts indicates that, within reason, spine stretching does not appear to be an unusual threat to gymnasts' health. However, the paucity of information demands that further study be undertaken.

The influence of joint hypermobility on functional movement control in an elite netball population: A preliminary cohort study

OBJECTIVES

To ascertain the prevalence of General Joint Hypermobility (GJH) and Joint Hypermobility Syndrome (JHS) in elite level netballers. To investigate whether GJH influences functional movement control and explore whether symptoms of dysautonomia are reported in this population.

DESIGN

Observational within-subject cross-sectional design.

SETTING

Field based study.

PARTICIPANTS

27 elite level netballers (14-26 years).

MAIN OUTCOME MEASURES

GJH and JHS were assessed using the Beighton scale, 5 point questionnaire and the Brighton Criteria. Functional movement control was measured using posturography on a force platform and the Star Excursion Balance Test (SEBT).

RESULTS

The prevalence of GJH was 63% (n = 17) (Beighton score ≥4/9) and JHS was 15% (n = 4). Symptoms of dysautonomia were minimally prevalent. A trend was observed in which participants with GJH demonstrated increased postural instability on the functional tests. Following Bonferroni adjustment, this was statistically significant only when comparing posturographic data between the distinctly hypermobile participants and the rest of the group for path area (p = 0.002) and velocity (p = 0.002) on the left side.

CONCLUSIONS

A high prevalence of GJH was observed. A trend towards impairment of functional movement control was observed in the netballers with GJH. This observation did not reach statistical significance except for posturographic path area and velocity.

Effect of a physical conditioning versus health promotion intervention in dancers: a randomized controlled trial

Although dancing requires extensive physical exertion, dancers do not often train their physical fitness outside dance classes. Reduced aerobic capacity, lower muscle strength and altered motor control have been suggested as contributing factors for musculoskeletal injuries in dancers. This randomized controlled trial examined whether an intervention program improves aerobic capacity and explosive strength and reduces musculoskeletal injuries in dancers. Forty-four dancers were randomly allocated to a 4-month conditioning (i.e. endurance, strength and motor control training) or health promotion program (educational sessions). Outcome assessment was conducted by blinded assessors. When accounting for differences at baseline, no significant differences were observed between the groups following the intervention, except for the subscale "Pain" of the Short Form 36 Questionnaire (p = 0.03). Injury incidence rate and the proportion of injured dancers were identical in both groups, but dancers following the conditioning program had significant less low back injuries (p = 0.02). Supplementing regular dance training with a 4-month conditioning program does not lead to a significant increase in aerobic capacity or explosive strength in pre-professional dancers compared to a health promotion program without conditioning training, but leads to less reported pain. Further research should explore how additional training may be organized, taking into account the demanding dance schedule of pre-professional dancers. The trial is registered at ClinicalTrials.gov, number NCT01440153.

Systematic review of chronic ankle instability in children

BACKGROUND

Chronic ankle instability (CAI) is a disabling condition often encountered after ankle injury. Three main components of CAI exist; perceived instability; mechanical instability (increased ankle ligament laxity); and recurrent sprain. Literature evaluating CAI has been heavily focused on adults, with little attention to CAI in children. Hence, the objective of this study was to systematically review the prevalence of CAI in children.

METHODS

Studies were retrieved from major databases from earliest records to March 2013. References from identified articles were also examined. Studies involving participants with CAI, classified by authors as children, were considered for inclusion. Papers investigating traumatic instability or instability arising from fractures were excluded. Two independent examiners undertook all stages of screening, data extraction and methodological quality assessments. Screening discrepancies were resolved by reaching consensus.

RESULTS

Following the removal of duplicates, 14,263 papers were screened for eligibility against inclusion and exclusion criteria. Nine full papers were included in the review. Symptoms of CAI evaluated included perceived and mechanical ankle instability along with recurrent ankle sprain. In children with a history of ankle sprain, perceived instability was reported in 23-71% whilst mechanical instability was found in 18-47% of children. A history of recurrent ankle sprain was found in 22% of children.

CONCLUSION

Due to the long-lasting impacts of CAI, future research into the measurement and incidence of ankle instability in children is recommended.

Standardization of the functional syndesmosis widening by dynamic U.S examination

Background

Dynamic US examination is a convenient, accurate, inexpensive and reproducible diagnostic tool for assessing the integrity of the distal tibiofibular syndesmosis in ankle injuries. However normal values for physiological functional widening of the anterior tibiofibular clear space in healthy subjects has yet to be determined. The purpose of this study was to determine normal values for the syndesmosis clear space on ultrasound examination.

Methods

We evaluated 110 healthy subjects. A dynamic U.S examination was performed in neutral (N), forced internal rotation (IR) and external rotation (ER) of the ankle. In each position the anterior tibiofibular clear space was measured at the level of the anterior inferior tibio-fibular ligament (AITFL). Height and calf length were also recorded. Results were analyzed in relation to age, activity, dominant leg and gender.

Results

Mean age was 32 years (range 16–60). There were 59 males and 51 females. 60% were professional athletes. Mean height was 173 cm (range 149–192). Functional Mean position measurements for clear space opening were: N=3.7mm, IR=3.6mm and ER=4.0mm. In younger men and women the clear space was significantly wider in neutral (Men: Y=3.8, O=3.4 \ Women: Y=3.8, O=3.4) and with rotational force application (Men ER: Y=4.1, O=3.6 \ Women ER: Y=4.1, O=3.8) compared to older subjects (p<0.05). There was no correlation with activity, height or the leg length.

Females had a higher syndesmosis widening ratio (ER/N) under stress than males (p<0.01) this tended to occur more commonly in active subjects.

Conclusions

Normal values for the syndesmosis clear space on ultrasound examination were determined as 3.78mm in neutral, 3.64mm in internal rotation and 4.08mm in external rotation. The clear space was shown to decrease with age both as an absolute measure and when rotational stresses are applied. Females tend to have a larger clear space and a greater functional widening.

These findings provide a useful reference for radiologists and sports physicians when performing ultrasound assessment of ankle syndesmotic injuries and we encourage use of this modality.

Dynamic balance during gait in children and adults with Generalized Joint Hypermobility

BACKGROUND

The purpose of the study was to investigate if differences of the head and trunk stability and stabilization strategies exist between subjects classified with Generalized Joint Hypermobility and healthy controls during gait. It was hypothesized that joint hypermobility could lead to decreased head and trunk stability and a head stabilization strategy similar to what have been observed in individuals with decreased locomotor performance.

METHODS

A comparative study design was used wherein 19 hypermobile children were compared to 19 control children, and 18 hypermobile adults were compared to 18 control adults. The subjects were tested during normal walking and walking on a line. Kinematics of head, shoulder, spine and pelvis rotations were measured by five digital video cameras in order to assess the segmental stability (angular dispersion) and stabilization strategies (anchoring index) in two rotational components: roll and yaw.

FINDINGS

Hypermobile children and adults showed decreased lateral trunk stability in both walking conditions. In hypermobile children, it was accompanied with decreased head stability as the head was stabilized by the inferior segment when walking on a line. Several additional differences were observed in stability and stabilization strategies for both children and adults.

INTERPRETATION

Stability of the trunk was decreased in hypermobile children and adults. This may be a consequence of decreased stability of the head. Hypermobile children showed a different mode of head stabilization during more demanding locomotor conditions indicating delayed locomotor development. The findings reflect that Generalized Joint Hypermobility probably include motor control deficits.

Simultaneous bilateral elbow dislocation with bilateral medial epicondyle fractures in a 13-year-old female gymnast with hyperlaxity

Bilateral simultaneous elbow dislocations are extremely rare and have only been described in 12 cases. In the paediatric population unilateral elbow dislocations are rare with 3-6% of all elbow injuries and there are only few studies describing this injury exclusively in children. There is only one case report of a paediatric patient who sustained a simultaneous bilateral elbow dislocation with medial epicondyle fractures. We present a second paediatric case of simultaneous bilateral elbow dislocation with associated displaced bilateral medial epicondyle fractures in a gymnast with joint hyperlaxity (3 of 5 Wynne-Davies criteria) treated with closed reduction and short-term immobilisation (3 weeks). The patient returned to full trampoline gymnastics between 4 and 5 months postinjury and made an uneventful recovery.

Gait analysis of adults with generalised joint hypermobility

BACKGROUND

The majority of adults with Generalised Joint Hypermobility experience symptoms such as pain and joint instability, which is likely to influence their gait pattern. Accordingly, the purpose of the present project was to perform a biomechanical gait analysis on a group of patients with Generalised Joint Hypermobility and compare them to a group of healthy subjects.

METHODS

Seventeen adults clinically classified with Generalised Joint Hypermobility (6 males and 11 females) and seventeen healthy subjects (9 males and 8 females) were included in the project. The subjects walked across three force platforms while they were filmed by five video cameras. Net joint moments were calculated in 3D by inverse dynamics and peak values were input to statistical analyses. A 3D knee joint model was used to calculate bone-on-bone forces.

FINDINGS

In the frontal plane both the peak knee and hip abductor moments were 13% higher in the patient group. In the sagittal plane the peak knee extensor moment was 10% higher for the patients and the flexor moment about the knee joint in the middle of stance was 27% lower for the patients. Increased flexion in the knee joint for the patients was also observed.

INTERPRETATION

The finding that adults with Generalised Joint Hypermobility display higher joint moments during walking in both the frontal and the sagittal planes and increased knee joint loadings may explain the pain symptoms in the patient group and indicate these subjects are subjected to an increased risk of developing osteo-arthritis.

Epidemiology of generalized joint laxity (hypermobility) in fourteen-year-old children from the UK: a population-based evaluation

Objective

Although diagnostic criteria for generalized ligamentous laxity (hypermobility) in children are widely used, their validity may be limited, due to the lack of robust descriptive epidemiologic data on this condition. The present study was undertaken to describe the point prevalence and pattern of hypermobility in 14-year-old children from a population-based cohort.

Methods

We performed a cross-sectional analysis using the Avon Longitudinal Study of Parents and Children, a large population-based birth cohort. Hypermobility among children in the cohort (mean age 13.8 years) was measured using the Beighton scoring system. Objective measures of physical activity were ascertained by accelerometry. Data on other variables, including puberty and socioeconomic status, were collected. Simple prevalence rates were calculated. Chi-square tests and logistic regression analyses were used to assess associations of specific variables with hypermobility.

Results

Among the 6,022 children evaluated, the prevalence of hypermobility (defined as a Beighton score of ≥4 [i.e., ≥4 joints affected]) in girls and boys age 13.8 years was 27.5% and 10.6%, respectively. Forty-five percent of girls and 29% of boys had hypermobile fingers. There was a suggestion of a positive association between hypermobility in girls and variables including physical activity, body mass index, and maternal education. No associations were seen in boys.

Conclusion

We have shown that the prevalence of hypermobility in UK children is high, possibly suggesting that the Beighton score cutoff of ≥4 is too low or that this scoring is not appropriate for use in subjects whose musculoskeletal system is still developing. These results provide a platform to evaluate the relationships between the Beighton criteria and key clinical features (including pain), thereby testing the clinical validity of this scoring system in the pediatric population.

Motor competence and physical activity in 8-year-old school children with generalized joint hypermobility

OBJECTIVE

Because the criteria used for diagnosing between generalized joint hypermobility (GJH) and musculoskeletal complaints, as well as relations between GJH and an insufficient motor development and/or a reduced physical activity level differ, the prevalence of GJH varies considerably. The aim of this study was to survey the prevalence of GJH defined by a Beighton score at >or=4, >or=5, or >or=6 positive tests of 9 and benign joint hypermobility syndrome (BJHS) in Danish primary school children at 8 years of age. A second aim was to compare children with and without GJH and BJHS regarding motor competence, self-reported physical activity, and incidence of musculoskeletal pain and injuries.

METHODS

A cross-sectional study of 524 children in the second grade from 10 public schools was performed. A positive response rate was obtained for 416 (79.4%) children, and 411 (78.4%) children were clinically examined and tested for motor competence, whereas questionnaire response to items comprising musculoskeletal pain and injuries, in addition to daily level and duration of physical activity, corresponded to 377 (71.9%) children.

RESULTS

In total, 29% of the children had GJH4, 19% had GJH5, 10% had GJH6, and 9% had BJHS, with no gender difference. There was no difference in daily level and duration of physical activity and in frequency of musculoskeletal pain and injuries between those with and without GJH. Children with >or=GJH5 as well as with >or=GJH6 performed better in the motor competence tests.

CONCLUSION

Motor competence and physical activity are not reduced in primary school children at 8 years of age with GJH or BJHS. It is recommended that a potential negative influence on the musculoskeletal system over time, as a result of GJH, be investigated by longitudinal studies.

Why do idiopathic scoliosis patients participate more in gymnastics?

The influence of physical and sporting activities (PSA) on idiopathic scoliosis (IS) is still obscure. The aim of this study was to investigate whether such an influence exists and if so, to determine its characteristics. Two hundred and one teenagers with IS and a control group of 192 adolescents completed an epidemiological questionnaire. Those practising gymnastics were more numerous in the IS group than in the control group. Moreover, the practice of gymnastics was chosen before IS was diagnosed. As gymnastic activities are considered neither as a therapy nor as a precursor of IS, the distribution observed could be linked to a common factor that both increases the likelihood of IS and favors the practice of gymnastics. Joint laxity (JL) may be such a common factor, and was therefore tested (wrist and middle finger) on 42 girls with IS and 21 girls of a control group. IS patients, practising gymnastics or not, showed a higher JL than the control group practising gymnastics or not. Furthermore, the groups practising gymnastic activities did not show higher JL levels than the other groups. Children with a high JL could be drawn toward gymnastics because of their ability to adapt to the constraints of this sport. Girls with a high JL may therefore be prone to developing IS. The fact that most teenagers with IS practise gymnastics could be related to a higher JL.

Generalized Joint Hypermobility Is More Common in Chronic Fatigue Syndrome Than in Healthy Control Subjects

OBJECTIVES

This study aimed at (1) comparing the prevalence of generalized hypermobility in patients with chronic fatigue syndrome (CFS) and healthy volunteers, (2) examining the clinical importance of generalized hypermobility in patients with CFS, and (3) examining whether knee proprioception is associated with hypermobility in patients with CFS.

METHODS

Sixty-eight patients with CFS filled out two self-reported measures (for the assessment of symptom severity and disability), were questioned about muscle and joint pain, and were screened for generalized hypermobility. Afterward, the patients performed a knee repositioning test (assessment of knee proprioception), and it was examined whether or not they fulfilled the criteria for benign joint hypermobility syndrome (BJHS). Sixty-nine age- and sex-matched healthy volunteers were screened for generalized joint hypermobility and performed the same knee repositioning test.

RESULTS

Compared with the healthy volunteers (4.3%, 3/68), significantly more patients with CFS (20.6%, 14/69) fulfilled the criteria for generalized joint hypermobility (Fisher exact test, P < .004). No associations were found between generalized joint hypermobility and the self-reported measures (including pain severity) or knee proprioception (Spearman correlation analysis). Knee proprioception was similar in both groups (Mann-Whitney U = 1961, z = -1.745, P = .81). Forty patients with CFS (58.8%) fulfilled the criteria for BJHS.

CONCLUSIONS

These data indicate that a subgroup of patients with CFS present with generalized joint hypermobility and most patients with of CFS fulfill the diagnostic criteria for BJHS. There appears to be no association between musculoskeletal pain and joint hypermobility in patients with CFS.

Neuromuscular response to cyclic loading of the anterior cruciate ligament

BACKGROUND

Cyclic load applied to various joints during occupational and sports activities is epidemiologically linked to higher risk of neuromuscular disorder development.

HYPOTHESIS

Passive cyclic loading of the knee will develop laxity and creep in the anterior cruciate ligament, and these may elicit a neuromuscular disorder in the quadriceps and hamstrings. Women may be more susceptible to the disorder.

STUDY DESIGN

Controlled laboratory study.

METHODS

Male and female groups were subjected to 10 minutes of passive cyclic loading (0.1 Hz) of the knee at a mild load (150-200 N) and at 35 degrees and 90 degrees flexion. Anterior tibial displacement and electromyogram from the quadriceps and hamstrings were monitored during cyclic loading. Maximal voluntary contraction of knee extension and flexion was assessed before and after cyclic loading. The effect of gender and angle on maximal voluntary contraction and quadriceps/hamstrings electromyogram was tested by a 2-way analysis of variance. Differences between the preload and postload data were tested by a paired t test.

RESULTS

At a knee angle of 90 degrees, after cyclic loading, a decrease in maximal voluntary contraction during extension was present in men and women, with an associated decrease in quadriceps electromyogram activity. At 35 degrees, a decrease in maximal voluntary contraction in extension was noted in women and men. Electromyogram spasms were present in the quadriceps and hamstrings during the 10-minute cyclic loading in 51.7% of subjects. Analysis of variance demonstrated that ligament creep was significantly greater in women than in men at both knee angles.

CONCLUSIONS

Even a mild cyclic loading of the anterior cruciate ligament, for a relatively short period, can elicit substantial creep, laxity, and a neuromuscular disorder. The disorder is composed of spasms and attenuated muscular function that may together create a condition that exposes the knee to injury. Women seem to be more susceptible than men.

CLINICAL RELEVANCE

Cyclic actions performed at high frequencies and high-load magnitudes may lead to the occurrence of increased knee laxity and changes in neuromuscular function that, together with fatigue and changes in proprioception, may increase the risk of injury.

Does generalised ligamentous laxity increase seasonal incidence of injuries in male first division club rugby players?

OBJECTIVES

To investigate if ligamentous laxity increases seasonal incidence of injury in male first division club rugby players, and to determine if strength protects against injury in hypermobile and tight players.

METHODS

Fifty one male first division club rugby players were examined for ligamentous laxity using the Beighton-Horan assessment and graded with an overall laxity score ranging from 0 (tight) to 9 (hyperlax). Each participant was classified into a group determined by their laxity score: tight (0-3), hypermobile (4-6), or excessively hypermobile (7-9). The incidence of joint injuries was recorded prospectively throughout the rugby season and correlated with laxity score. Differences between the groups were analysed.

RESULTS

The overall prevalence of generalised joint hypermobility was 24% (12/51). The incidence of injuries was significantly higher in hypermobile (116.7 per 1000 hours) than tight (43.6 per 1000 hours) players (p = 0.034). There were no significant differences in peak strength between the hypermobile and tight groups.

CONCLUSIONS

The laxity of the players may explain the differences in injury rates between these groups. Peak strength does not protect the hypermobile joint against injury. It appears that hypermobility may cause an increase in the injury rate of male first division club rugby players.