Altered lumbopelvic movement control but not generalized joint hypermobility is associated with increased injury in dancers. A prospective study

The effect of chronic low back pain and lumbopelvic stabilization instructions on gluteus medius activation during sidelying hip movements

BACKGROUND

People with chronic low back pain (LBP) often demonstrate altered muscle activation with movements that involve the lumbopelvic region and hips.

OBJECTIVE

The purpose of this study was to compare gluteus medius activity during sidelying hip abduction (SHA) and sidelying hip abduction-lateral rotation (SHALR) with and without instruction for lumbopelvic stabilization in people with and without chronic LBP.

METHODS

A cross-sectional study was conducted recruiting participants with (n = 17) and without (n = 17) chronic LBP. Gluteus medius activity was recorded with surface electromyography during the performance of SHA and SHALR with and without instructions including the abdominal drawing-in maneuver for lumbopelvic stabilization.

RESULTS

For SHA and SHALR, there was a significant main effect for instruction for stabilization indicated by a decrease in gluteus medius activity with instructions (p = .001, p < .001). There was not a significant main effect of chronic LBP on gluteus medius activity between groups for either activity. There was no significant interaction effect of pain and instruction for stabilization with SHA or SHALR.

CONCLUSION

Knowledge of changes in gluteus medius muscle activation patterns with trunk stabilization instruction may help clinicians with assessment of exercise performance to optimize gluteus medius activation.

Relationships Between Common Preseason Screening Measures and Dance-Related Injuries in Preprofessional Ballet Dancers

OBJECTIVE: To examine modifiable and nonmodifiable factors for associations with dance-related injury among preprofessional ballet dancers over 5 academic years. DESIGN: Prospective cohort study. METHODS: Full-time preprofessional ballet dancers (n = 452; 399 female; median age [range], 15 years [11-21]) participated across 5 academic years at a vocational school. Participants completed baseline screening and online weekly injury questionnaires including dance exposure (hours/week). Zero-inflated Poisson regression models were used to examine associations between potential risk factors measured at baseline and self-reported dance-related injury. RESULTS: In count model coefficients, left one leg standing score (log coefficient estimate, -0.249 [95% CI: -0.478, -0.02]; P = .033) and right unipedal dynamic balance time (log coefficient estimate, -0.0294 [95% CI: -0.048, -0.01]; P>.001) carried a protective effect with increased years of training when adjusted for Athletic Coping Skills Inventory (ACSI) score. A significant association was found for left unipedal dynamic balance time and dance-related injury (log coefficient estimate, 0.013 [95% CI: 0.000, 0.026]; P = .045) when adjusted for years of training and ACSI score. There were no significant associations between dance-related injury and ankle and hip range of motion, active straight leg raise, or Y Balance Test measures. CONCLUSION: When adjusted for years of previous dance training and psychological coping skills, there was a significant association between limb-specific lumbopelvic control and dynamic balance tasks, as well as self-reported dance-related injury in preprofessional ballet. J Orthop Sports Phys Ther 2023;53(11):703-711. Epub 3 October 2023. doi:10.2519/jospt.2023.11835.

The Effects of Abdominal Hollowing and Bracing Maneuvers on Trunk Muscle Activity and Pelvic Rotation Angle during Leg Pull Front Pilates Exercise

Pilates methods use mats for trunk muscles stabilization exercises, and leg pull front (LPF) is one of the traditional Pilates mat exercises. Abdominal hollowing (AH) and Abdominal bracing (AB) maneuvers are recommended to stabilize the trunk muscles and prevent unwanted pelvic movement during motion. This study aimed to explore the effects of AH and AB on electromyography (EMG) activity of the trunk muscles and angle of pelvic rotation during LPF. A total of 20 healthy volunteers participated in the study. AH, AB, and without any condition (WC) were randomly performed during LPF exercise. Each was repeated three times for 5 s. The trunk muscle activities were measured using EMG and rotation of pelvis was measured using a Smart KEMA device. The activities of the transversus abdominis/obliquus internus abdominis (TrA/IO) and right obliquus externus abdominis (EO) muscles were highest in LPF-AH compared to the other conditions. Multifidus (MF) activity was significantly greater in LPF-AH and LPF-AB compared to that of without any condition. The pelvic rotation angle was significantly smaller in LPF-AB. Therefore, AH maneuver during LPF for trunk muscle stabilization exercises is suitable for selective activation of the TrA/IO, and AB maneuver during LPF is recommended for the prevention of unwanted pelvic rotation.

Effect of low back pain on clinical-functional factors and its associated potential risk of chronicity in adolescent dancers of classical ballet: cross-sectional study

BACKGROUND

Low back pain (LBP) is a common symptom in classical ballet dancers, which can limit their daily activities and dance training routines. The purpose of the study was to verify the association and comparison of clinical-functional outcomes (spine flexibility and foot posture) between different levels of intensity low back pain in adolescents of classical ballet and the potential risk of chronicity using the STarT back tool.

METHODS

Cross-sectional study.

PARTICIPANTS

78 adolescent girls who practice classical ballet were evaluated and divided into groups according to level of low back pain: mild (n = 21), moderate (n = 17), and high (n = 20), and a control group (n = 20).

MAIN OUTCOME MEASURES

Pain, flexibility of the spine (thoracic and lumbosacral), risk of chronicity for low back pain, and foot posture were assessed using the visual analogue scale, clinical tests, STarT back screening tool (SBST) questionnaire, and foot posture index (FPI), respectively.

RESULTS

Dancers with high-intensity low back pain showed a potential risk of chronicity by the SBST. The spine pain intensity was not different considering thoracic and lumbosacral flexibility in the sagittal plane, but was different with greater supine FPI when compared to control dancers. Mild low back pain was associated with greater supine FPI. The SBST score was associated with higher exposure time-frequency and time of dancing.

CONCLUSION

Adolescents of classical ballet with high-intensity low back pain showed a potential risk of chronicity by the SBST. The level of intensity low back pain did not influence the clinical-functional aspects of spine flexibility in the sagittal plane, but the level of intensity moderate pain promoted changes in foot posture (more supinated). The potential risk of chronicity using the SBST was also associated with higher exposure time-frequency and time of dancing, in adolescents of classical ballet.

The effects of abdominal hollowing and bracing on abdominal muscle thicknesses and pelvic rotation during active straight leg raise

BACKGROUND: Active straight leg-raise (ASLR) is often performed to strengthen abdominal muscles. The correct execution and maximum benefit of the ASLR can be achieved using abdominal hollowing (AH) and abdominal bracing (AB) exercises. OBJECTIVE: To compare the effects of AH and AB on transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) thicknesses, as well as on the pelvic rotation angle, in healthy women during active ASLR. METHODS: The participants in this study were assigned randomly to either the AH (n= 15) or AB groups (n= 15). During ASLR, abdominal muscle thickness was measured using ultrasound and pelvic rotation was measured using a Smart KEMA device. Each trial was repeated three times for 5 s each. RESULTS: The thickness of the TrA was significantly greater during ASLR with AH than during ASLR with AB (p< 0.001). In contrast, there was no respective significant change in the thickness of the EO (p> 0.311) or IO (p> 0.818). Pelvic rotation angle was significantly reduced during ASLR with AB, compared with ASLR with AH (p< 0.018). CONCLUSIONS: We recommend that AH be performed for the selective contraction of TrA during ASLR, and that AB be performed for the prevention of the pelvic rotation during ASLR. Therefore, AH and AB should be separately done in stabilization exercises.

Association between pre-participation characteristics and risk of injury amongst pre-professional dancers

STUDY DESIGN

Prospective Cohort Study.

BACKGROUND

Few investigations utilize evidence-informed pre-participation evaluation, inclusive injury definitions, and prospective surveillance to identify risk factors for dance-related injuries.

OBJECTIVE

To evaluate pre-participation characteristics that may be associated with greater odds of dance-related musculoskeletal complaints in pre-professional dancers.

METHODS

Full-time pre-professional ballet [n = 85, 77 females, median (range) age 15-years (11-19)] and contemporary [n = 60, 58 females, 19-years (17-30)] dancers underwent pre-participation evaluation: baseline questionnaire, coping skills, body mass index, bone mineral density, ankle range-of-motion, active standing turnout, lumbopelvic control, and balance tests. Self-reported complaints (any physical problem making dance participation difficult, irrespective of medical attention or time-loss) were captured weekly via online questionnaires for one academic year. Self-reported musculoskeletal complaints were recorded weekly (yes/no). Potential risk factors were identified a-priori through systematic review. Associations between potential risk factors and musculoskeletal complaints were examined with generalized linear mixed method regression models.

RESULTS

Response rate was 99%, with 81% of dancers reporting at least one musculoskeletal complaint. Of 1521 complaints (19% first-time, 81% ongoing), the ankle (22%), knee (21%), and foot (12%) accounted for the majority. Injury history [odds ratio (OR) 7.37 (95% CI 3.41, 15.91)] and previous week's dance hours [OR 1.02 (1.01, 1.03)] were associated with dance-related musculoskeletal complaints.

CONCLUSIONS

Prevalence of musculoskeletal complaints amongst pre-professional dancers is high and associated with injury history and training volume. Further understanding of the relationship between training load and injury is needed, with particular consideration of the dynamic and recursive nature of dance injury etiology.

LEVEL OF EVIDENCE

Therapy / Prevention, Aetiology / Harm, level 2b.

Sagittal Integral Morphotype of Female Classical Ballet Dancers and Predictors of Sciatica and Low Back Pain

The aims of this study were to describe the sagittal integral morphotype (SIM) of classical ballet (CB) dancers, and to establish predictor factors and their cut off values for high risk of experiencing sciatica or low back pain (LBP). This retrospective cohort study was performed in 33 female professional CB dancers. Data related to anthropometric parameters, CB dance experience, sciatica or LBP history, and sagittal spine curvatures were collected. A binary logistic regression and receiver-operating characteristic analysis were performed. The main spine misalignments observed in the SIM of CB dancers were thoracic functional hyperkyphosis, hypomobile kyphosis, and hypokyphosis, and those for the lumbar curvature were hyperlordotic attitude and functional hyperkyphosis. The lumbar curvature in slump sitting and trunk forward bending positions, together with the stature, were significant predictor factors of sciatica history, while the years of dance experience was a significant predictor factor of LBP history. The cut off values analysis revealed that dancers with a stature of 161 cm or less, and those with 14 years of experience or more, have a greater probability of experiencing sciatica or LBP history, respectively.

The Impact of Dance-Specific Neuromuscular Conditioning and Injury Prevention Training on Motor Control, Stability, Balance, Function and Injury in Professional Ballet Dancers: A Mixed-Methods Quasi-Experimental Study

BACKGROUND

Professional ballet dancers suffer high injury rates and are less likely than other athletes to specifically train to improve muscular strength, coordination, agility, speed and motor control because of heavy training demands, aesthetic appearances and financial barriers.

HYPOTHESIS/PURPOSE

The purpose of this study was to examine the effects of a supplemental conditioning program on professional and pre-professional contemporary ballet dancers. The authors hypothesized that those participating in a training program would reduce injury rate by improving their motor control, stability, balance and physical function. The authors aimed to observe the feasibility and qualitative phenomena related to a conditioning program from the dancer's perspective.

STUDY DESIGN

A mixed-methods study; within subject quasi-experimental design and qualitative interviews.

METHODS

Six professional classical and contemporary ballet dancers completed the five-week conditioning and injury prevention training program. Non-parametric analysis of baseline, posttest and four-month follow-up physical performance measures, subjective outcomes, and qualitative follow-up interviews, were reported.

RESULTS

Significant post-test improvements included: The Dance Functional Outcome Survey (Z= -2.2, p= 0.04), composite Modified Star Excursion Balance Test (Z= -2.2, p= 0.03 bilaterally), Single Leg Hop for Distance (Z= -2.02, p= 0.04), and Upper Extremity Closed Kinetic Chain Test (Z=-2.03, p= 0.04). Significant changes from baseline to the four-month follow up remained for: (1) Dance Functional Outcome Survey (Z= -2.2, p= 0.03), (2) Single Leg Hop for Distance (Z= -2.2, p= 0.03), and (3) Modified Star Excursion Balance Test composite maximum reach for the left lower extremity (Z= -2.2, p= 0.03).

CONCLUSION

Completing a conditioning and prevention program for professional ballet dancers was related to improved function, balance, hop distance/stability and upper extremity stability. Dancers found the program beneficial, identified barriers to participation, and elucidated factors making the program feasible and successful. More research is necessary to determine the effect of such programs on injury incidence.

LEVEL OF EVIDENCE

3b.

The standing knee lift test is not a useful screening tool for time loss from low back pain in youth basketball and floorball players

OBJECTIVES

The aim of this study was to investigate the association between pelvic kinematics during the standing knee lift (SKL) test and low back pain (LBP) in youth floorball and basketball players.

DESIGN

A prospective cohort study.

SETTING

Finnish elite youth floorball and basketball players.

PARTICIPANTS

Finnish elite youth female and male floorball and basketball players (n = 258, mean age 15.7 ± 1.8).

MAIN OUTCOME MEASURES

LBP resulting in time loss from practice and games was recorded over a 12-month period and verified by a study physician. Associations between LBP and sagittal plane pelvic tilt and frontal plane pelvic obliquity during the SKL test as measured at baseline were investigated. Individual training and game hours were recorded, and Cox's proportional hazard models with mixed effects were used for the analysis.

RESULTS

Cox analyses revealed that sagittal plane pelvic tilt and frontal plane pelvic obliquity were not associated with LBP in floorball and basketball players during the follow-up. The hazard ratios for pelvic tilt and pelvic obliquity ranged between 0.93 and 1.08 (95% CIs between 0.91 and 1.07 and 0.83 and 1.29), respectively.

CONCLUSIONS

Pelvic movement during the SKL test is not associated with future LBP in youth floorball and basketball players.

Generalized Joint Hypermobility and Injuries: A Prospective Cohort Study of 185 Pre-Professional Contemporary Dancers

Generalized joint hypermobility (GJH) has been mentioned as one of the factors associated with dance injuries, but the findings are inconclusive. This study aims to investigate whether GJH, based on different Beighton score cut-off points, is a potential risk factor for injuries in pre-professional dancers. Four cohorts of first-year pre-professional dancers (N = 185), mean age 19.1 ± 1.3 years, were screened on musculoskeletal functioning at the start of their academic year. The Beighton score was used to measure GJH. During the academic year, the dancers completed monthly questionnaires about their physical and mental health. Based on the Oslo Sports Trauma Research Centre Questionnaire on Health Problems (OSTRC), three injury definitions were used (i.e., all complaints, substantial injury, and time-loss injury). To examine potential risk factors for injuries, univariate and multivariate regression models were applied. The response rate of monthly completed questionnaires was 90%. The overall mean (SD) Beighton score was 2.8. The 1-year injury incidence proportion was 67.6% (n = 125), 43.2% (n = 80), and 54.6% (n = 101) for all complaint injuries, substantial injuries, and time-loss injuries, respectively. The multivariate analyses showed a significant association between a previous long lasting injury in the past year and the three injury definitions (p < 0.05). Pre-professional contemporary dancers are at high risk for injuries and hypermobility. However, these two variables are not associated with each other. Health professionals should take injury history into account when assessing dance students, because this variable is associated with increased injury risk.

Risk Factors for Lower-Extremity Injuries in Female Ballet Dancers: A Systematic Review

BACKGROUND

Ballet dancers have a high prevalence of injuries to the lower extremity. Many studies have investigated the relationship between dance injury and risk factors. However, risk factors for lower-extremity injury comparing recreational- and elite-level ballet dancers are scarce.

OBJECTIVE

To systematically review available original studies to assess risk factors for lower-extremity injury in female ballet dancers between recreational and elite ballet dancers.

DATA SOURCES

Five online databases [Web of Science, PubMed, OVID (Medline), EBSCO, and ProQuest] were searched systematically.

STUDY SELECTION

Included studies had an analytic study design published in the past 11 years and investigated an association between potential risk factors and lower-extremity injury in female ballet dancers.

STUDY APPRAISAL

Assessed independently by 2 reviewers using the Downs and Black (DB) criteria and Oxford Centre of Evidence-Based Medicine.

RESULTS

Seventeen studies were included. Alignment was a risk factor for lower-extremity injury in both recreational and elite ballet dancers. In elite ballet dancers, poor lumbopelvic movement control, inappropriate transversus abdominis contraction, decreased lower-extremity strength, and poor aerobic fitness were risk factors for lower-extremity injury. In recreational ballet dancers, hypermobility of the hip and ankle and longer training hours were risk factors for lower-extremity injury. Mean DB score was 15.94 (SD 1.57). The majority of studies were retrospective cohort studies or had poor follow-up, with 7 level 2b studies, 6 level 3b studies (cross-sectional), and 4 level 1b studies (prospective cohort with good follow-up).

CONCLUSIONS

Alignment was identified as a common risk factor for recreational and elite ballet dancers. Other risk factors differed between recreational ballet dancers and elite ballet dancers. Future studies are warranted to use a prospective study design, identify dance level-specific risk factors, and implement evidence-based prevention strategies.

An Injury Prevention Program for Professional Ballet: A Randomized Controlled Investigation

BACKGROUND

Few investigations have examined dance-specific injury prevention programs (IPPs), and no published randomized controlled trials are available that evaluate IPPs for dance.

HYPOTHESIS

The implementation of an IPP will significantly reduce the risk of injury in professional ballet dancers.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

A randomized controlled trial was designed that entailed a superiority model for the intervention group. All professional dancers from a single ballet company were eligible to participate. Randomization and allocation were performed before the start of the season. The control group practiced and performed without change to preexisting standard operating practice. The IPP group was instructed to perform a 30-minute exercise program 3 times per week over the 52-week study period. Injuries were recorded. Standard continuous and categorical data comparisons and correlations were used. Cox proportional hazards regression models for recurrent failures were used wherein the hazard ratio indicates the relative likelihood of injury in the control versus intervention groups.

RESULTS

Of the 52 eligible dancers, 75% (n = 39) participated. Of these 39 dancers, 19 (9 males, 10 females; mean age, 26.6 ± 4.0 years) were randomized to the control group and 20 (11 males, 9 females; mean age, 25.1 ± 5.1 years) to the IPP group. No significant (P > .05) difference was found in baseline demographics between groups. A total of 116 injuries were recorded for the entire study population (49 IPP; 67 control). Traumatic and chronic injuries accounted for 54% and 46% of injuries, respectively. The injury rate was 82% less (IPP hazard ratio, 0.18; z = -2.29; P = .022) in the IPP group after adjustment for confounding variables, and time between injuries was 45% longer (IPP hazard ratio, 0.55; z = -2.20; P = .028) than for controls.

CONCLUSION

The present study is the first prospective randomized controlled investigation of an IPP for professional ballet. The results showed an 82% decrease in injury rate for the intervention group and an extended period from previous injury to subsequent injury.

REGISTRATION

NCT04110002 (ClinicalTrials.gov identifier).

Performance in dynamic movement tasks and occurrence of low back pain in youth floorball and basketball players

BACKGROUND

Prospective studies investigating risk factors for low back pain (LBP) in youth athletes are limited. The aim of this prospective study was to investigate the association between hip-pelvic kinematics and vertical ground reaction force (vGRF) during landing tasks and LBP in youth floorball and basketball players.

METHODS

Three-hundred-and-eighty-three Finnish youth female and male floorball and basketball players (mean age 15.7 ± 1.8) participated and were followed up on for 3 years. At the beginning of every study year the players were tested with a single-leg vertical drop jump (SLVDJ) and a vertical drop jump (VDJ). Hip-pelvic kinematics, measured as femur-pelvic angle (FPA) during SLVDJ landing, and peak vGRF and side-to-side asymmetry of vGRF during VDJ landing were the investigated risk factors. Individual exposure time and LBP resulting in time-loss were recorded during the follow-up. Cox's proportional hazard models with mixed effects and time-varying risk factors were used for analysis.

RESULTS

We found an increase in the risk for LBP in players with decreased FPA during SLVDJ landing. There was a small increase in risk for LBP with a one-degree decrease in right leg FPA during SLVDJ landing (HR 1.09, 95% CI 1.02 to 1.17, per one-degree decrease of FPA). Our results showed no significant relationship between risk for LBP and left leg FPA (HR 1.04, 95% CI 0.97 to 1.11, per one-degree decrease of FPA), vGRF (HR 1.83, 95% CI 0.95 to 3.51) or vGRF side-to-side difference (HR 1.22, 95% CI 0.65 to 2.27) during landing tasks.

CONCLUSIONS

Our results suggest that there is an association between hip-pelvic kinematics and future LBP. However, we did not find an association between LBP and vGRF. In the future, the association between hip-pelvic kinematics and LBP occurrence should be investigated further with cohort and intervention studies to verify the results from this investigation.

LEVEL OF EVIDENCE

Prognosis, level 1b.

Relationship Between Lumbar Motor Control Ability and Spinal Curvature in Elderly Individuals

This study aimed to clarify the relationship between spine curvature and the movement pattern/motor control ability of the lumbar and hip joints during prone hip extension in elderly individuals. The participants were 14 elderly people who attended a community health class. We measured the motion angle, motion ratio (movement pattern), and motor control ability of the lumbar and hip joints during prone hip extension. In addition, the lumbar lordosis angle and thoracic kyphosis angle were measured in the standing position. There was no correlation between the spinal curvature in the standing position and the lumbar/hip joint movement pattern and motor control ability during prone hip extension. When evaluating the lumbar spine, it is necessary to perform a comprehensive evaluation by interpreting static evaluations such as spinal alignment or dynamic evaluations such as movement patterns and motor control abilities.

Risk of Injury in Physically Active Students: Associated Factors and Quality of Life Aspects

Background: The aim of this study was to assess the potential factors of hypermobility and pain threshold on the risk of injury in physically active students and to verify which domains of quality of life are rated lower by young people with a history of injuries. Methods: The study included 278 students (138 women and 140 men) who regularly undertake physical activity. Anthropometric measurements, body composition, pain threshold, incidence of hypermobility syndrome, information on the history of injuries to the locomotor system, and the quality of life of the study participants were collected. Results: In the group studied, hypermobility and pain threshold had a statistically significant related on the risk of injury. Participants with a history of injuries had lower scores for an individual’s overall perception of their own health and the physical domain. There were also significant differences in the psychological domain of the quality of life between males and females with a history of injuries. Conclusion: In the studied group, the risk of injuries was related to diagnosed hypermobility and pain threshold measured on the lower limbs. The study also showed that people with a history of injuries had statistically significantly lower scores in the individual general perception of their own health and in the physical domain. Gender had a significant impact on the quality of life of people with injuries.

Assessment of movement coordination strategies to inform health of movement and guide retraining interventions

INTRODUCTION

Exploring characteristics of human movement has long been the focus of clinicians and researchers. Changes in movement coordination strategies have been identified in the presence of pain highlighting the need for assessment in clinical practice. A major development in the understanding of movement related disorders is recognition of individual differences in presentation and consequently the need to tailor interventions based on assessment.

PURPOSE

The purpose of this masterclass is to build a rationale for the clinical assessment of movement coordination strategies, exploring loss of movement choices, coordination variability, and to present a clinical framework for individualised management, including the use of cognitive movement control tests and retraining interventions. An approach for the qualitative rating of movement coordination strategies is presented. A compromised movement system may be one characterised by a lack of ability to access motor abundance and display choice in the use of movement coordination strategies. The identification of lost movement choices revealed during the assessment of movement coordination strategies is proposed as a marker of movement health.

IMPLICATIONS FOR PRACTICE

The health of the movement system may be informed by the ability to display choice in movement coordination strategies. There is evidence that restoring these choices has clinical utility and an influence on pain and improved function. This approach seeks to provide individuals with more flexible problem solving, enabled through a movement system that is robust to each unique challenge of function. This assessment framework sits within a bigger clinical reasoning picture for sustained quality of life.

Diagnostic accuracy of lumbopelvic motor control tests using pressure biofeedback unit in professional swimmers: A cross-sectional study

Hypothesis

To determine the effect of receiving the visual feedback of the sphygmomanometer on lumbopelvic motor control (LPMC) tests in professional swimmers.

Method

31 professional swimmers to participate in the study. The outcome was maximum absolute mmHg variation in the pressure biofeedback unit's manometer with and without visual feedback on four LPMC tests.

Results

Test scores were significantly affected by visual feedback F = 10.07, p = 0.002, η² _p = 0.117 and the type of test F = 32.53, p < 0.001, η² _p = 0.300.

Conclusion

Visual feedback has a positive effect on the Active Straight Leg Raise Test (ASLR), the Knee Lift Abdominal Test (KLAT) scores completed by professional swimmers.

Movement Control Impairment and Low Back Pain: State of the Art of Diagnostic Framing

Background and objectives: Low back pain is one of the most common health problems. In 85% of cases, it is not possible to identify a specific cause, and it is therefore called Non-Specific Low Back Pain (NSLBP). Among the various attempted classifications, the subgroup of patients with impairment of motor control of the lower back (MCI) is between the most studied. The objective of this systematic review is to summarize the results from trials about validity and reliability of clinical tests aimed to identify MCI in the NSLBP population. Materials and Methods: The MEDLINE, Cochrane Library, and MedNar databases have been searched until May 2018. The criteria for inclusion were clinical trials about evaluation methods that are affordable and applicable in a usual clinical setting and conducted on populations aged > 18 years. A single author summarized data in synoptic tables relating to the clinical property; a second reviewer intervened in case of doubts about the relevance of the studies. Results: 13 primary studies met the inclusion criteria: 10 investigated inter-rater reliability, 4 investigated intra-rater reliability, and 6 investigated validity for a total of 23 tests (including one cluster of tests). Inter-rater reliability is widely studied, and there are tests with good, consistent, and substantial values (waiter's bow, prone hip extension, sitting knee extension, and one leg stance). Intra-rater reliability has been less investigated, and no test have been studied for more than one author. The results of the few studies about validity aim to discriminate only the presence or absence of LBP in the samples. Conclusions: At the state of the art, results related to reliability support the clinical use of the identified tests. No conclusions can be drawn about validity.

Efficiency examination of a 6-month trunk prevention program among recruitment kayak-canoe athletes: A randomized control trial

BACKGROUND

Trunk prevention training, which provides the basis of several conditioning training programs, is used in sports at professional and amateur levels, taking the specifications of the given sport and the age-related characteristics of the athletes into consideration.

OBJECTIVE

Our aim was to examine the strength and flexibility of muscles responsible for correct posture, the lumbar motor control ability and the posture of recruitment kayak-canoe athletes.

METHODS

Controlled, randomized examination with 103 persons (age: 15.1 ± 3.5 years), who were divided into two groups. Fifty were in the intervention group, who took part in the 6-month trunk prevention training program (height: 162.30 cm, body weight: 49.70 ± 10.32 kg), 53 in the control group (not performing trunk prevention training) (height: 158.24 cm, body weight: 51.45 ± 11.71 kg). The strength of core muscles was measured with Kraus-Weber test, muscle flexibility with Kempf-test, lumbar motor control ability with Sitting Forward Lean and Leg Lowering test and posture with photogrammetry test before and after the program.

RESULTS

Static strength of abdominal muscles (p< 0.001), superficial and deep dorsal muscles (p< 0.001), flexibility of knee extensors (p< 0.001), chest muscles (p< 0.001), the lumbar motor control ability (p< 0.001) and habitual posture (p< 0.001) significantly improved in the intervention group. The post-measurements in the intervention group were significantly (p< 0.001) better than in the control group.

CONCLUSIONS

As a result of the trunk prevention training the strength of core stabilization muscles, the lumbar motor control ability and the posture also improved in case of recruitment athletes.

Links between the Hip and the Lumbar Spine (Hip Spine Syndrome) as they Relate to Clinical Decision Making for Patients with Lumbopelvic Pain

This narrative review focuses on the links between the hip and lumbar spine in the context of lumbopelvic pain. The literature regarding this topic is variable, found in many disciplines of care using different terminology. Collectively these inconsistencies add to the complexity of understanding the current evidence as it pertains to clinical practice. We have chosen to review studies that describe and assess overlapping pain distributions between the lumbar spine and hip, hip osteoarthritis and lumbopelvic pain, improvements in low back pain following hip arthroplasty, association of hip range of motion and lumbopelvic pain, and lumbopelvic motion and hip motion as they relate to low back pain and gender. The links between the hip and lumbar spine may provide the clinician important information to make decisions and recommendations for people presenting with the clinical symptom complex including lumbopelvic pain.

Can Biomechanics Research Lead to More Effective Treatment of Low Back Pain? A Point-Counterpoint Debate

SYNOPSIS

Although biomechanics plays a role in the development and perhaps the persistent or recurrent nature of low back pain (LBP), whether biomechanics alone can provide the basis for intervention is debated. Biomechanics, which refers to the mechanics of the body, including its neuromuscular control, has been studied extensively in LBP. But, can gains be made in understanding LBP by research focused on this component of biology in the multifactorial biopsychosocial problem of LBP? This commentary considers whether biomechanics research has the potential to advance treatment of LBP, and how likely it is that this research will lead to better treatment strategies. A point-counterpoint format is taken to present both sides of the argument. First, the challenges faced by an approach that considers biomechanics in isolation are presented. Next, we describe 3 models that place substantial emphasis on biomechanical factors. Finally, reactions to each point are presented as a foundation for further research and clinical practice to progress understanding of the place for biomechanics in guiding treatment of LBP. J Orthop Sports Phys Ther 2019;49(6):425-436. Epub 15 May 2019. doi:10.2519/jospt.2019.8825.

Association Between Previous Injury and Risk Factors for Future Injury in Preprofessional Ballet and Contemporary Dancers

OBJECTIVES

To determine the prevalence of self-reported 1-year injury history and examine its association with preparticipation evaluation components aimed at predicting future injury risk (PPE-IP) among preprofessional ballet and contemporary dancers.

DESIGN

Cross-sectional study.

SETTING

Preprofessional ballet school, university contemporary dance program.

PARTICIPANTS

Full-time preprofessional ballet and contemporary dancers.

ASSESSMENT OF RISK FACTORS

Preparticipation evaluation consisted of the Athletic Coping Skills Inventory-28, body mass index, total bone mineral density, ankle range of motion, active standing turnout, lumbopelvic control, unipedal dynamic balance, and Y-Balance test.

MAIN OUTCOME MEASURE

Self-reported 1-year history of dance-related medical attention and/or time-loss injury.

RESULTS

A total of 155 ballet [n = 90, 80 females, median age 15 years (range 11-19)] and contemporary [n = 65, 63 females, median age 20 years (range 17-30)] dancers participated. Forty-six percent (95% confidence interval (CI), 38.4-54.6) reported a 1-year injury history. Self-reported injury history was not associated with any PPE-IP, however, an influence of age and psychological coping skills on the relationship between 1-year injury history and PPE-IP was identified. Multivariable analyses revealed that prevalence of 1-year injury history did not differ by age [referent group <15 years; 15-18 years: odds ratio (OR) 0.80 (95% CI, 0.35-1.79); >18 years: OR 0.69 (95% CI, 0.30-1.56)], or level of psychological coping skills [OR 1.35 (95% CI, 0.61-2.94)].

CONCLUSIONS

The prevalence of self-reported 1-year injury history among preprofessional ballet and contemporary dancers is high. Although measures of PPE-IP did not differ based on injury history, it is important that age and psychological coping skills are considered in future dance injury prevention and prediction research.

LEVEL OF EVIDENCE

Level 3 evidence.

The Epidemiology of Low Back Pain and Injury in Dance: A Systematic Review

BACKGROUND

Dance is a physical pursuit that involves loading the spine through repetitive dynamic movements and lifting tasks. As such, low back pain (LBP) and low back injury (LBI) have been identified as common health problems in contemporary and classical ballet dancers. However, clarity regarding the experience of LBP and LBI in dance is lacking.

OBJECTIVES

To systematically review and synthesize the epidemiology of LBP and LBI in dance populations.

METHODS

A comprehensive search of 6 electronic databases, back catalogs of dance science-specific journals, and reference lists of relevant articles and a forward citation search were performed.

RESULTS

Fifty full-text articles were included in the final systematic review. There was considerable methodological heterogeneity among the included studies. The median (range) point, yearly, and lifetime prevalence of LBP was 27% (17%-39%), 73% (41%-82%), and 50% (17%-88%), respectively. The lower back contributed to 11% (4%-22%) of time loss and 11% (5%-23%) of medical-attention injuries.

CONCLUSION

Dancers are vulnerable to LBP and LBI. The use of definitions that are sensitive to the complexity of LBP and LBI would facilitate improved understanding of the problem within dance, inform health care strategies, and allow for monitoring LBP-specific intervention outcomes. J Orthop Sports Phys Ther 2019;49(4):239-252. Epub 18 Jan 2019. doi:10.2519/jospt.2019.8609.

Hypermobility of joints in dancers

OBJECTIVES

The current understanding of hypermobility and its diagnostic criteria is still insufficient to create a complete and systematic clinical presentation of the disorder. The objective of this study was to assess the prevalence of joint hypermobility syndrome (JHS) amongst a cohort of jazz dancers, by analyzing its presence in accordance with a number of diagnostic criteria, and to verify potential risk factors for joint hypermobility in jazz dancers.

METHODS

77 jazz dancers from the Polish Dance Theater were examined (58 female and 19 male). The prevalence of JHS was assessed using the following diagnostic tools: a structured interview, Beighton score, Grahame & Hakim questionnaire, and Sachse's criteria, in the modified version proposed by Kapandji.

RESULTS

The prevalence of JHS in this cohort of jazz dancers differed significantly, depending on which criteria were adopted (p = 0.001) with Beighton score, Grahame & Hakim questionnaire, and Sachse's criteria identifying 64.9%, 74% and 59.7% of the sample as JHS respectively. Hypermobility was significantly more prevalent in women than men (p < 0.05).

CONCLUSIONS

This study demonstrated a significant prevalence of joint hypermobility in jazz dancers and corroborates the findings of other researchers, indicating the need for unified diagnostic criteria for JHS in dancers.

Functional muscle asymmetries and laterality in Latin American formation dancers

BACKGROUND

Despite the high popularity of Latin American dance and the specific movement patterns characteristic of this dance discipline, studies on the physical effects of these dance style specific movement patterns are still lacking.

OBJECTIVE

The purpose of the present study is to analyze strength level differences and shortening of relevant muscle groups resulting from formation dance, taking performance standard and gender into consideration. Furthermore, the correlation between the findings of muscle function tests (MFT) and the occurrence of lumbar spine complaints is evaluated.

METHODS

A total of 66 participants (m: n= 31, f: n= 35) volunteered for this cross-sectional study (examination group, n= 39, m: n= 19, f: n= 20). The control group consisted of n= 27 participants (m: n= 12, f: n= 15). Besides isometric maximal strength tests (Digi Max system, mechaTronic), relevant muscle groups were examined for shortenings (hip flexors, hamstrings).

RESULTS

The male participants in dance sport reached a significantly higher strength level in the muscles of the spine region (p= 0.011) than the participants of the control group. The female elite dance athletes developed a significantly higher strength level in the knee flexors on the right side than the dancers of the advanced group (NL) (p= 0.021). At that, muscle shortening were observed that seem to be specific to dance sport. In addition, gender specific differences were observed both in strength levels and in tendency to shortenings.

CONCLUSION

The specific requirements profile of Latin American formation dance seems to produce affects in the form of muscular imbalance on both sides of the body. These differences of muscular status were mainly observed between dance sport competitors and non-dancers rather than between performance levels. Future investigations with higher numbers of participants would be necessary here.

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.

Screening Tools as a Predictor of Injury in Dance: Systematic Literature Review and Meta-analysis

BACKGROUND

Dance involves movements of complexity and physical intensity which result in stress on the body. As a consequence, dancers are at risk of injury which can impact on their well-being. Screening tools are used for injury prevention to identify those dancers at risk of injury. The aim of this study was to investigate which screening tools can predict injury in dancers, encompassing all dance genres, levels and ages.

METHODS

An electronic search of seven databases from their inception to December 2017 was conducted. The databases were the Allied and Complementary Medicine Database (AMED), CINAHL, eBOOK Collection (EBSCOhost), MEDLINE, Cochrane Database of Systematic Reviews, SPORTDiscus and PEDro: the Physiotherapy Evidence Base. The following search terms were used: (i) Dance AND injury AND Screening, (ii) Screening AND dance and (iii) Musculoskeletal AND Screening AND Dance. Studies were assessed using a 20-point scoring tool, and eligible studies were included in a meta-analysis.

RESULTS

The mean methodological quality score was 12.2 points. Injured dancers had a significantly higher compensated turnout range of motion than non-injured dancers: pooled mean difference of compensated turnout (23.29°; 95% CI 14.85-31.73; P < 0.00001; I² = 0%). Injured dancers had significantly greater functional turnout range of motion when compared to non-injured dancers: pooled mean difference of functional turnout (14.08°; 95% CI 7.09-21.07; P < 0.0001; I² = 0%). There also some evidence for use of hip range of motion as a predictor of dance injury.

CONCLUSIONS

Some evidence exists for the potential use of dance-specific positions as a predictor of injury. A number of studies were limited by a lack of prospective injury design, injury definition and self-reporting of injury.

Motor skill training in musculoskeletal pain: a case report in chronic low back pain

Purpose: Low back pain is a chronic condition that limits function. The chief reason individuals with low back pain seek care is difficulty performing functional activities. A novel approach to improving performance of painful and limited functional activities is motor skill training, defined as challenging practice of activities to learn or relearn a skill. The purpose of this report is to describe the design and application of a motor skill training intervention in a 26-year-old man with a 10-year history of low back pain. Methods: A motor skill training intervention was implemented to modify the altered alignment and movement patterns he used during the performance of his painful and limited activities. Results: The patient was seen for six visits in 12 weeks. The patient reported decreased pain and medication use, as well as improved function immediately, 3-, and 9-months post-intervention. Conclusion: Individuals with low back pain report limitation in ability to perform everyday functions and demonstrate altered patterns of movement and alignment during these activities. This case report describes an innovative motor skill training intervention that directly addresses the performance of functional activities and the application of motor learning principles. Implications for rehabilitation Low back pain is a chronic condition that limits function. The chief reason individuals with chronic low back pain seek care is difficulty performing everyday functional activities. Motor skill training is a novel approach that directly addresses the performance of painful and limited functional activities through challenging practice to improve performance and decrease pain.

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.

Within/between-session reliability and agreement of lumbopelvic kinematics in the sagittal plane during functional movement control tasks in healthy persons

A lack of adequate lumbopelvic movement control has been suggested as an underlying mechanism contributing to the development and persistence of low back pain and lower limb pathologies. The purpose of this study was to assess the within and between session reliability (i.e. the ability to discriminate between subjects), and the agreement (i.e. whether scores are identical on repeated measures) of lumbopelvic kinematics in the sagittal plane during functional movement control tasks. Kinematics were measured with a portable inertial measurement unit system. Twenty healthy subjects (mean age = 22 (±3.6) years, 15 females) performed four tasks on two occasions, five to seven days apart: standing bow (SB), lifting a box from the floor (LIFT), stance-to-sit-to-stance (SIT) and placing a box on an overhead shelf (OVERH). Participants were asked to keep the lumbar spine in a neutral lordosis during the tasks. The maximal deviations from the neutral starting position for the lumbar spine and hip were calculated. Intraclass correlations (ICCs), standard errors of measurement (SEM), minimal detectable changes and 95% limits of agreement were used to assess reliability and agreement. SB and LIFT were substantially reliable (ICC = 0.89-0.96), SIT was moderately to substantially reliable (ICC = 0.69-0.92) and OVERH was fairly to moderately reliable (ICC = 0.40-0.67). SEMs ranged between 1.1° and 3.1° for the lumbar spine and between 0.7° and 4.8° for the hip. Based on the substantial reliability and acceptable agreement, SB and LIFT are most appropriate to quantify lumbopelvic movement control during functional tasks.

Rehabilitation of a Young Athlete With Extension-Based Low Back Pain Addressing Motor-Control Impairments and Central Sensitization

OBJECTIVE

  To describe the conservative management of a young athlete with extension-based (EB) low back pain (LBP).

BACKGROUND

  We present the case of a 15-year-old female high school gymnast with a 4-year history of EB LBP. Magnetic resonance imaging revealed a healed spondylolysis and significant atrophy with fatty infiltrate of the lumbar multifidi muscles (LMM). She had several courses of outpatient orthopaedic rehabilitation that focused on core muscle strengthening (improving activation and strength of the LMM and transversus abdominus muscle in a neutral pelvic position) without long-lasting improvement. She was unable to tolerate higher levels of training or compete.

DIFFERENTIAL DIAGNOSIS

  The LMM are rich in muscle spindles and provide continuous feedback to the central nervous system about body position. Atrophy and fatty infiltrate of the LMM can compromise neuromuscular function and contribute to dysfunctional movement patterns that place a greater demand on lumbar spine structures. Ongoing motor-control impairments perpetuate nociceptive input, leading to central sensitization.

TREATMENT

  The athlete had difficulty controlling trunk extension during sport-specific activities; she moved early and to a greater extent in the lumbar spine. The aim of the treatment was to teach the athlete how to control her tendency to overload her lumbar spine when bending backward, thus reducing nociceptive input from lumbar spine structures and desensitizing the nervous system.

UNIQUENESS

  Treating EB LBP by addressing motor-control impairments and cognitive-affective factors as opposed to core strengthening.

CONCLUSIONS

  Activity modification, bracing, and traditional core-strengthening exercises may not be the most appropriate treatment for athletes experiencing EB LBP. Addressing cognitive-affective factors in addition to correcting maladaptive motor behavior and moving in a pain-free range reduces nociceptive input, desensitizes the nervous system, and allows athletes to gain control over their pain.

Twenty-Year Systematic Review of the Hip Pathology, Risk Factors, Treatment, and Clinical Outcomes in Artistic Athletes-Dancers, Figure Skaters, and Gymnasts

OBJECTIVE

To identify (1) the predominant level of evidence of the clinical studies regarding the hip pathology, risk factors, treatment, and clinical outcomes in artistic athletes (dancers, figure skaters, and gymnasts) (2) the most commonly reported hip pathology, risk factors, treatments, and clinical outcomes in dancers, figure skaters, and gymnasts.

METHODS

To conduct this systematic review PubMed, EMBASE, and Scopus databases were searched for relevant studies and pertinent data were collected from the eligible articles. Included were studies which reported hip injuries in artistic athletes, the risk factors, treatment, and/or the clinical outcomes. We excluded case reports or irrelevant studies. No meta-analysis was performed because of study heterogeneity. The methodical index for nonrandomized studies (MINORS) criteria were used for quality control.

MAIN RESULTS

Thirty-eight studies were included in the analysis. The mean MINORS score was 13.6 ± 4.6 points indicating fair quality of evidence of the included articles. The predominant level of evidence was level IV. Chondrolabral pathology and muscle injuries were the most commonly reported pathologies. We found only 2 risk factor analysis studies; however, many studies reported risk correlation between artistic sports or imaging findings and hip pathology. Treatment strategies were reported in only 7 studies, clinical outcomes are significantly underreported.

CONCLUSION

Chondrolabral pathology was the most commonly reported hip pathology in artistic athletes, however, prospective cohort studies are necessary to really understand these injuries and their associated risk factors. The lack of clinical outcomes is significant and future data collection is required to assess the effectiveness of the various treatments.

INJURIES IN PROFESSIONAL DANCERS: A SYSTEMATIC REVIEW

ABSTRACT Movement is a fundamental element of dance, and the dancer’s body is the raw material through which the art of dance is expressed; for this, it demands the utmost discipline in the pursuit of technical and artistic excellence. To meet the professional demands, dancers are subjected to strenuous training routines, which can lead to the development of injuries in this environment. The objective was to examine the etiology, main affected segments, prevalence, and instruments used to evaluate the lesions in studies with professional dancers and/or in comparison with similar populations. We selected articles published in the last decade in the databases BIREME, LILACS, MEDLINE EBSCO, WEB OF SCIENCE, SCOPUS (Elsevier), and PubMed, with cross-sectional, observational cohort and case control design published in Portuguese, English, or Spanish. Systematic reviews, case studies, dissertations, theses, book chapters, cross-referenced articles, and studies published outside of the last decade were not included. The search used combinations of the terms “dancing* and athletic injuries* and musculoskeletal* and pain*”. A principal investigator and two reviewers conducted the survey and analyzed all the potentially relevant articles, initially by the abstract and title. Twelve articles were included, with 1,149 participants (965 professional dancers of classical ballet, modern dance, contemporary dance, and breakdance, 104 amateur dancers, and 80 elite athletes). Nine studies found simultaneous lesions with emphasis on the foot and ankle (n=4), upper and lower limbs lesions (n=4) and lower and upper limb joints (n=1). Other studies have found lesions in the anterior cruciate ligament (n=3). There was no agreement regarding the instruments for detecting lesions in professional, pre-professional, and amateur dancers. There was a prevalence of studies aimed at classical ballet modality, evidencing a higher frequency of lower limb involvement in professional dancers.

Diagnosis and treatment of movement system impairment syndromes

BACKGROUND

Diagnoses and treatments based on movement system impairment syndromes were developed to guide physical therapy treatment.

OBJECTIVES

This masterclass aims to describe the concepts on that are the basis of the syndromes and treatment and to provide the current research on movement system impairment syndromes.

RESULTS

The conceptual basis of the movement system impairment syndromes is that sustained alignment in a non-ideal position and repeated movements in a specific direction are thought to be associated with several musculoskeletal conditions. Classification into movement system impairment syndromes and treatment has been described for all body regions. The classification involves interpreting data from standardized tests of alignments and movements. Treatment is based on correcting the impaired alignment and movement patterns as well as correcting the tissue adaptations associated with the impaired alignment and movement patterns. The reliability and validity of movement system impairment syndromes have been partially tested. Although several case reports involving treatment using the movement system impairment syndromes concept have been published, efficacy of treatment based on movement system impairment syndromes has not been tested in randomized controlled trials, except in people with chronic low back pain.

Measurement properties of clinical assessment methods for classifying generalized joint hypermobility-A systematic review

The purpose was to perform a systematic review of clinical assessment methods for classifying Generalized Joint Hypermobility (GJH), evaluate their clinimetric properties, and perform the best evidence synthesis of these methods. Four test assessment methods (Beighton Score [BS], Carter and Wilkinson, Hospital del Mar, Rotes-Querol) and two questionnaire assessment methods (Five-part questionnaire [5PQ], Beighton Score-self reported [BS-self]) were identified on children or adults. Using the Consensus-based Standards for selection of health Measurement Instrument (COSMIN) checklist for evaluating the methodological quality of the identified studies, all included studies were rated "fair" or "poor." Most studies were using BS, and for BS the reliability most of the studies showed limited positive to conflicting evidence, with some shortcomings on studies for the validity. The three other test assessment methods lack satisfactory information on both reliability and validity. For the questionnaire assessment methods, 5PQ was the most frequently used, and reliability showed conflicting evidence, while the validity had limited positive to conflicting evidence compared with test assessment methods. For BS-self, the validity showed unknown evidence compared with test assessment methods. In conclusion, following recommended uniformity of testing procedures, the recommendation for clinical use in adults is BS with cut-point of 5 of 9 including historical information, while in children it is BS with cut-point of at least 6 of 9. However, more studies are needed to conclude on the validity properties of these assessment methods, and before evidence-based recommendations can be made for clinical use on the "best" assessment method for classifying GJH. © 2017 Wiley Periodicals, Inc.

KINEMATIC DIFFERENCES IN LUMBOPELVIC AND HIP MOVEMENT PATTERNS DURING A LOWER LIMB MOVEMENT TEST BETWEEN TWO GROUPS OF PEOPLE WITH LOW BACK PAIN

Increased lumbopelvic motion during limb movements’ tests was reported in low back pain (LBP) patients with and without rotational demand activities. The aim of this study was to compare lumbopelvic movement pattern between two groups of LBP patients with and without rotational demand activity during active hip external rotation test. A total of 39 patients with non-specific chronic LBP participated in this study. Patients were allocated into two groups, in first group 15 subjects (mean [Formula: see text] years) with rotational demand activities such as tennis, squash and golf, and in second group 24 subjects (mean [Formula: see text]) without rotational demand activities participated in current study. Kinematic data from lumbopelvic-hip region during active hip external rotation test (AHER) were collected by a 3D motion analysis system. Variables including range of motion (ROM) of hip external rotation, pelvic rotation, pelvic rotation during first half of hip rotation motion and timing of pelvic-hip movement were calculated by MATLAB software for both sides and after this, independent t-test was used to compare the variables between two groups of study. The mean lumbopelvic rotation in lower extremities tests for both sides and lumbopelvic rotation in the dominant limb external rotation test in the patients with rotational demand activities were significantly more than other group ([Formula: see text]). During dominant lower limb movement test, pelvic rotation in first half of movement and in patients with rotational activities was greater than in non-rotational group but hip rotation was statistically lesser than other group ([Formula: see text]). Other variables between the two groups were not significantly different ([Formula: see text]). The result of the study suggest that LBP patients who have rotational demand sports activities may move their lumbopelvic region in a greater magnitude during the AHER test than LBP people without rotational demand activities. Therefore, Lumbopelvic movement pattern in different groups of patients with LBP and based on their specific activities is different with each other.

Generalized Joint Laxity and Ligament Injuries in High School-Aged Female Volleyball Players in Japan

Background:

Generalized joint laxity has been linked to ligamentous injuries such as anterior cruciate ligament tear and ankle sprain.

Purpose/Hypothesis:

The purpose of this study was to investigate generalized joint laxity and incidence of ligament injuries in high school–aged female volleyball players. It was hypothesized that volleyball players with a past history of sprains would have increased generalized joint laxity compared with those without any history and that athletes with multiple sprains would demonstrate with a higher generalized joint laxity score than those who had only 1 sprain.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

Forty-seven subjects were tested for generalized joint laxity using the Beighton and Horan Joint Mobility Index (BHJMI). They were categorized into 2 groups based on the presence of past ligament injury: injury group (IG) and noninjury group (NG). The IG group was further divided into 2 groups based on whether they had a single ligamentous injury (IGS) or multiple injuries (IGM) in the past to study whether there was any difference in scores between the subgroups. The collected data were analyzed statistically with 1-way analysis of variance.

Results:

Subjects in the IG group scored significantly higher on the BHJMI than those in the NG group. The mean score for the IG group was 2.40 ± 1.42, as opposed to 1.24 ± 1.09 for the NG group (P = .006). Eleven subjects in the IG group had suffered multiple injuries or recurrent injuries (IGM) and scored significantly higher than the remaining 19 individuals in the IG group, who had only sustained a single injury (IGS). The mean BHJMI scores were 3.18 ± 1.47 and 1.95 ± 1.22 for IGM and IGS, respectively (P = .02).

Conclusion:

Female athletes with a high generalized joint laxity score may be more prone to ligament injury and potentially to recurrent ligament injuries.

Risk factors for back pain in marines; a prospective cohort study

Background

It is recognised that back pain (BP) is a debilitating medical problem in the soldier community, which limits operational readiness as well as work ability. As such, identification of risk factors is a necessity for effective preventive actions, but also regarded as important from a safety perspective. The aim of this prospective cohort study was therefore to identify risk factors for back pain and BP limiting work ability in active duty marines within a 6 and 12-month period.

Methods

Demographic characteristics, health-related factors and occupational exposure information, as gathered from questionnaires, as well as clinical test of movement control among 137 Swedish marines were regressed with multivariable logistic regressions, and strength of associations was presented as odds ratio (OR) with 95 % confidence intervals (CI). BP within 6 and 12 months were used as primary outcomes, whereas BP limiting work ability within 6 and 12 months served as secondary outcomes.

Results

Previous BP and tall body height (≥1.86 m) emerged as risk factors for back pain within 6 months (OR 2.99, 95 % CI 1.22–7.30; OR 2.81, 95 % CI 1.16– 6.84, respectively), and 12 months (OR 6.75, 95 % CI 2.30–19.80; 2.75, 95 % CI 1.21–6.29, respectively). Previous BP was also identified as risk factor for BP limiting work ability within 12 months (OR 6.64, 95 % CI 1.78–24.78), and tall body height emerged as a risk within both six (OR 4.30, 95 % CI 1.31–14.13) and 12 months (OR 4.55, 95 % CI 1.53–13.57) from baseline.

Conclusions

Marines with a history of BP are at risk of further BP episodes, which, thus, emphasise the importance of early BP preventive actions. Tall body height also emerged as an important risk which may reflect that personal equipment and work tasks are not adapted for the tallest marines. While this should be considered when introducing new work equipment, further studies are warranted to clarify the underlying mechanism of this association.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1172-y) contains supplementary material, which is available to authorized users.

Hip pain in dancers

Dancers require extreme ranges of motion in their hips. They require this for many styles and performances. Hip pain and hip injury in dancers can lead to lost work and performance time. There are many potential causes for hip pain in the dancer, including dysplasia, hyperlaxity, both intra- and extra-articular impingement, and soft tissue injuries. This article will review the current literature on these topics in dancers and how they can be applied to the dancer patient.