Muscle strength differences in healthy young adults with and without generalized joint hypermobility: a cross-sectional study

The Effect of Attention Focus Instructions on Strength and Balance in Subjects With Generalized Joint Hypermobility

This study aims to examine the effects of different attention focuses on muscle strength and balance performance in individuals with Generalized Joint Hypermobility (GJH). This randomized crossover trial included 32 individuals with GJH whose Beighton score was greater than 5. Subjects performed each task under external attentional focus, internal attentional focus, and neutral attentional focus condition. Knee extensor muscle strength was measured using the Isokinetic Dynamometer. Postural stability was evaluated using the Biodex Balance System, while dynamic balance was assessed using the Y Balance Test. The main effects of attentional focus on the outcomes were analyzed using repeated measures ANOVA and post-hoc corrections with a 95% confidence interval. Subjects produced significantly higher quadriceps peak torque during external focus instruction and internal focus instruction compared to neutral condition (p = .006). Postural stability performance were found to be better during external attention focus compared to the internal focus of attention and the neutral group (p = .008). In addition, an increase in Y balance composite score was observed during external condition compared to internal condition and neutral condition (p < .001). Whether internal or external, the use of attentional focus may be beneficial for optimal force production during training in individuals with GJH. External attention focus enabled better postural stability and dynamic balance performances.

The strength of balance: Strength and dynamic balance in children with and without hypermobility

BACKGROUND

Generalized Joint hypermobility (GJH) is predominantly non-symptomatic. In fact, individuals with joint flexibility usually perform better than their non-hypermobile counterparts during physical activities. Notwithstanding, strength and balance are essential to maintain the control of the extra range of motion during activities and to prevent musculoskeletal complications. There are limited and conflicting pieces of evidence in literature regarding the association between strength and balance in children with GJH.

OBJECTIVES

The purpose of this study was to examine differences in functional strength, dynamic balance, proprioception, and isometric strength in children with and without joint hypermobility and determine the association between strength outcomes and dynamic balance.

METHOD

A cross-sectional study was conducted among children aged 6 to 11. Hypermobility was determined using the Beighton Score, with scores ≥6 representing hypermobility. Functional strength was assessed with the Functional Strength Measure (FSM), isometric strength was determined with a handheld dynamometer (HHD), the Y-Balance Test (YBT) was used to assess dynamic balance and the Wedges test to measure proprioception.

RESULTS

This study included 588 participants (age: 7.97 ± 1.3 years; height: 128±10.1 cm; mass: 27.18 ± 7.98 kg). 402 children were classified as having normal mobility and 186 as being hypermobile. Hypermobile children had better functional strength in the lower extremities than children with normal range mobility but lower reach distance in the YBT. No differences in proprioception, functional strength of the upper extremity or isometric strength in the hands were found. However, isometric lower extremity force was less in hypermobile children than children with normal range mobility. Irrespective of their joint mobility, a fair significant correlation existed between total Y-balance distance and FSM items r = 0.16-0.37, p = 0.01. Correlations between total Y-balance distance and isometric strength of knee and ankle muscles ranged between r = 0.26-0.42, p = 0.001.

CONCLUSION

Hypermobile joints seem to co-occur with lower extremity isometric strength, more functional strength in the lower extremities and less reaching distance in dynamic balance. The opposing direction of the results on functional and isometric strength tests highlights the importance of the type of outcome measures used to describe the association of strength and the range of motion.

Effects of single and repeated bouts of flywheel exercise on jump performance and muscle damage in athletes and non athletes

BACKGROUND

Although recent studies have investigated the effects of flywheel (FW) training on muscle function, the effects of transient FW exercise on jump performance in athletes are unknown. This study examined the effects of single and repeated bouts of FW squat exercises on jump performance and muscle damage in male collegiate basketball players.

METHODS

The participants were 10 healthy college-age men (nonathletes) and 11 male basketball players (athletes). The intervention involved 100 squat exercises (10 repetitions × 10 sets) using an FW device. To examine the repeated-bout effects, the protocol was conducted again after a 2-week interval. Squat jumps, countermovement jumps, drop jumps, and rebound jumps were evaluated as jump performance, while isometric maximal voluntary contraction (MVC) torque in knee extension, muscle soreness, range of motion, thigh circumference, muscle thickness, and echo intensity were evaluated as markers of muscle damage. Measurements were taken at baseline, immediately after exercise, 24 h later, and 72 h later.

RESULTS

The jump performance of nonathletes decreased after exercise (p < 0.05), while that of the athletes did not. The results were similar for muscle soreness. MVC torque decreased significantly after the first exercise in both groups (p < 0.05) and was significantly lower in the nonathletes versus athletes. Significant repeated-bout effects were found for muscle soreness in nonathletes but not athletes.

CONCLUSIONS

These results suggest that a single bout of FW exercise reduces jump performance in male nonathletes but not basketball players.

Does Increased Femoral Anteversion Can Cause Hip Abductor Muscle Weakness?

BACKGROUND

Increased femoral anteversion (IFA) causes functional problems (i.e., tripping, frequently falling, and fatigue) by affecting the pelvis and lower extremity biomechanics. In the frontal plane, increased contralateral pelvic drop and ipsilateral hip adduction, which are mainly considered deteriorated hip abductor muscle mechanisms, are associated with hip and knee injuries.

AIMS

The aim of this study was to examine the effects of femoral anteversion on hip abductor weakness and frontal plane pelvis-hip biomechanics during walking.

METHODS

The study included nine subjects with increased femoral anteversion and a control group of eleven subjects. Maximum isometric voluntary contraction (MIVC) values of the hip abductor muscles were measured with a handheld dynamometer. Three-dimensional gait analysis was performed for kinetic, kinematic, and temporo-spatial gait parameters. Non-parametric tests were used for statistical analysis (p < 0.05).

RESULTS

There was no significant difference found between the MIVC values of the IFA and control groups (p = 0.14). Moreover, no significant difference was determined between the ipsilateral peak hip adduction (p = 0.088) and contralateral pelvic drop (p = 0.149) in the stance phase. Additionally, there was no correlation between the peak hip adduction angle in the stance phase and normalized MIVC values in the IFA group (r = -0.198, p = 0.44), or in the control group (r = -0.174, p = 0.55). The deviations of pelvic rotation (p = 0.022), hip internal rotation (p = 0.003), and internal foot progression (p = 0.022), were found to be higher in the IFA group than in the controls.

CONCLUSIONS

IFA may not be associated with hip abductor muscle weakness, and it may not lead to the hip adduction and pelvic depression that can be seen in hip abductor weakness. Increased pelvic rotation and internal hip rotation during walking might be considered as a compensation for the femoral head-acetabulum alignment mechanism in the frontal plane.

Prevalence and Demographic Distribution of Hypermobility in a Random Group of School-Aged Children in Nigeria

BACKGROUND

The purpose of this study was to determine the prevalence of hypermobility in randomly selected healthy children, without previous trauma or disease process affecting the joints and whether other demographic variables (age, sex, BMI) had an impact on Beighton scores and range of motion (RoM) in children between 6 and 10 years of age.

RESULTS

286 children were included; 27.3% of them had a Beighton score ≥7/9 and 72% would be classified hypermobile if we had used a Beighton cut-off score ≥4/9. Prevalence declined with increasing age. Girls were more often hypermobile (34%) than boys (20%) and this was mainly caused by increased RoM in the knees. Positive scores of finger items of the Beighton were more common than on the other items, leading to a high prevalence of peripheral hypermobility. Localized hypermobility was only found in the fifth MCP joint. A total of 15% of the children with normal mobility reached 20 excess degrees RoM of the left and right fifth MCP. Pain was present in 12 of the 239 children but was not linked to the level of mobility.

CONCLUSION

Hypermobility is the rule in this pain-free population of children with GJH.

The reference values for muscle mass and strength in healthy Indian adults using whole-body potassium counter and isokinetic dynamometer

The study aims to define the sex-based reference data for muscle mass and strength among healthy young Indians and to compare the data from the present study with available literature. Healthy Indian adults (n = 100) aged between 18 and 40 years were recruited. The assessment of muscle mass and strength was performed. The body cell mass (BCM), fat-free mass, and muscle strength parameters were significantly higher among males compared to females (P < 0.001). A comparison of the current study data with the available literature showed that though BCM was comparable, Indians demonstrated a significantly lower isometric peak torque (P < 0.001 for both sexes). These findings suggest that Indians tend to have a lower muscle strength compared to the Western population, despite having a comparable BCM content.

Supervised, Heavy Resistance Training Is Tolerated and Potentially Beneficial in Women with Knee Pain and Knee Joint Hypermobility: A Case Series

Introduction

Adults with generalised joint hypermobility including knee joint hypermobility (GJHk) report more knee joint symptoms when compared to adults without GJHk. There is no consensus on best practice for symptom management. For instance, controversy exists regarding the appropriateness and safety of heavy resistance training as an intervention for this specific group. This case series aims to describe a supervised, progressive heavy resistance training program in adults with GJHk and knee pain, the tolerability of the intervention, and the outcomes of knee pain, knee-related quality of life, muscle strength, proprioception, and patellar tendon stiffness through a 12-week period.

Materials and Methods

Adults with GJHk and knee pain were recruited to perform supervised, progressive heavy resistance training twice a week for 12 weeks. The main outcome was the tolerability of the intervention. Secondary outcomes were knee pain during a self-nominated activity (VASNA); Knee injury and Osteoarthritis Outcome Score (KOOS); Tampa Scale of Kinesiophobia (TSK); maximal quadriceps voluntary isometric contraction and rate of torque development; 5 repetition maximum strength in five different leg exercises; single leg hop for distance; knee proprioception and patellar tendon stiffness.

Results

In total, 16 women (24.2 years, SD 2.5) completed at least 21/24 training sessions. No major adverse events were observed. On average, VASNA decreased by 32.5 mm (95% CI 21.4-43.6), in addition to improvements in KOOS and TSK scores. These improvements were supported by an increase in all measures of lower extremity muscle strength, knee proprioception, and patellar tendon stiffness.

Conclusion

Supervised heavy resistance training seems to be well tolerated and potentially beneficial in young women with GJHk and knee pain.

International Perspectives on Joint Hypermobility: A Synthesis of Current Science to Guide Clinical and Research Directions

ABSTRACT

There is exponential clinical and research interest in joint hypermobility due to recognition of the complexity of identification, assessment, and its appropriate referral pathways, ultimately impacting management. This state-of-the-science review provides an international, multidisciplinary perspective on the presentation, etiology, and assessment of joint hypermobility, as it presents in those with and without a systemic condition. We synthesize the literature, propose standardizing the use of terminology and outcome measures, and suggest potential management directions. The major topics covered are (i) historical perspectives; (ii) current definitions of hypermobility, laxity, and instability; (iii) inheritance and acquisition of hypermobility; (iv) traditional and novel assessments; (v) strengths and limitations of current assessment tools; (vi) age, sex, and racial considerations; (vii) phenotypic presentations; (viii) generalized hypermobility spectrum disorder and hypermobility Ehlers-Danlos syndrome; and (ix) clinical implications and research directions. A thorough understanding of these topics will equip the reader seeking to manage individuals presenting with joint hypermobility, while mindful of its etiology. Management of generalized joint hypermobility in the context of a complex, multisystem condition will differ from that of acquired hypermobility commonly seen in performing artists, specific athletic populations, posttrauma, and so on. In addition, people with symptomatic hypermobility present predominantly with musculoskeletal symptoms and sometimes systemic symptoms including fatigue, orthostatic intolerance, and gastrointestinal or genitourinary issues. Some also display skeletal deformities, tissue and skin fragility, and structural vascular or cardiac differences, and these warrant further medical follow-up. This comprehensive review on the full spectrum of joint hypermobility will assist clinicians, coaches/sports trainers, educators, and/or researchers in this area.

Comparison and correlation of cervical proprioception and muscle endurance in general joint hypermobility participants with and without non-specific neck pain-a cross-sectional study

Background

Cervical proprioception and muscle endurance are essential for maintaining cervical functional joint stability. Proprioception and muscle endurance may be impaired in those with general joint hypermobility (GJH). Examining these aspects is crucial. This study's aims are to (1) compare the cervical joint position error (JPE) and muscle endurance holding capacities in GJH individuals with and without non-specific neck pain (NSNP) (2) to assess the relationship between hypermobility Beighton scores, cervical JPE's, and muscle endurance in GJH individuals with and without NSNP.

Methods

In this cross-sectional comparative study, 33 GJH participants with NSNP (mean age 21.7 ± 1.8 years) and 35 asymptomatic participants GJH (mean age 22.42 ± 1.7 years) participated. Beighton's score of ≥4 of 9 tests was used as criteria to diagnose GJH. Cervical JPEs were estimated in degrees using a cervical range of motion device, and muscle endurance (flexor and extensor) were estimated in seconds using a stopwatch.

Results

GJH participants with NSNP showed significantly larger cervical JPEs (p < 0.001) and decreased muscle endurance holding times (p < 0.001) compared to asymptomatic participants. Beighton hypermobility scores showed a significant moderate positive correlation with cervical JPEs (flexion: r = 0.43, p = 0.013), left rotation: r = 0.47, p = 0.005, right rotation: r = 0.57, p = 0.001) in NSNP individuals. Also, Beighton hypermobility scores showed a moderate negative correlation with muscle endurance in NSNP (flexor muscles: r = -0.40, p = 0.020, extensor muscles: r = -0.41, p = 0.020, and asymptomatic individuals (flexor muscles: -0.34, p = 0.045, extensor muscles: r = -0.45, p = 0.007).

Conclusion

GJH individuals with NSNP showed increased cervical JPEs and reduced muscle endurance compared to asymptomatic. Individuals with GJH with higher Beighton scores demonstrated increased cervical JPEs and reduced neck muscle endurance holding ability. In clinical practice, therapists should be aware of these findings, incorporate proprioceptive and muscle endurance assessments, and formulate rehabilitation strategies for NSNP individuals with GJM.

Hip and Knee Weakness and Ankle Dorsiflexion Restriction in Individuals Following Lateral Patellar Dislocation: A Case-Control Study

OBJECTIVE

To explore the relationship between ankle dorsiflexion range of motion (ROM) and hip and knee muscle strength between patients with a history of patellar dislocation (PD) to healthy controls.

DESIGN

Case-control study.

SETTING

Orthopedical specialty outpatient clinic at a tertiary hospital.

PARTICIPANTS

Eighty-eight individuals were recruited; 44 individuals aged 16 years or older, of both sexes, with a history of at least one episode of atraumatic unilateral or bilateral PD requiring emergency care (14 men; 30 women; mean age 20 years) and 44 healthy (control) individuals (11 men; 33 women; mean age 21 years) matched for age, weight, and height to PD cases.

INTERVENTION

Assessment of hip and knee strength and ankle dorsiflexion ROM.

OUTCOME MEASURES

Ankle dorsiflexion ROM was assessed through the lunge test with a goniometer. Hip and knee muscle strength was evaluated through isometric hand-held dynamometry. Differences between healthy and control individuals were assessed using Student t Tests and Mann-Whitney U Test.

RESULTS

Patellar dislocation individuals presented with a reduced ankle dorsiflexion ROM [mean difference (MD): 9 degrees; effect size (ES): 1.39; P < 0.001] and generalized hip and knee weakness (MD range: 4.74 kgf to 31.4 kgf; ES range: 0.52-2.35; P < 0.05) compared with healthy subjects.

CONCLUSION

Individuals with a history of PD have reduced ankle dorsiflexion ROM and hip and knee muscle strength compared with healthy controls.

Prevalence of joint hypermobility in children and adolescents: A systematic review and meta-analysis

Background:

The inconsistent results of different studies regarding the prevalence of joint hypermobility (JH) or joint laxity in children and adolescents made us conduct a meta-analysis on the prevalence of JH in this age group.

Materials and Methods:

We searched electronic databases including Trip, Scopus, Medline, Embase, PubMed, and Google Scholar; some Iranian databases including Iran Medex and Magiran; and Scientific Information Database to find studies in which the prevalence of JH in children and adolescents had been reported since January 1990 to April 2017. In this process, two researchers evaluated the articles separately while they were not aware of each other's method, and they extracted and matched the information.

Results:

Necessary data of twenty studies (15,097 boys and 6048 girls) were entered into this meta-analysis. The age range in these studies was 3–19 years. According to the meta-analysis conducted on the twenty studies, it was determined that the total prevalence of JH among children and adolescents was 34.1% (95% confidence interval [CI]: 33.3%–34.8%). Based on the results obtained from the studies, a significant heterogeneity (I₂ index equals to 99,415 and P ≤ 0.001) was shown, so we used random-effects model; moreover, the overall assessment of studies showed a statistically significant publication bias (P = 0.02). In total, the prevalence in girls was equal to 32.5% (95% CI: 31.4%–33.7%), and in boys, it was equal to 18.1% (95% CI: 17.2%–19.1%).

Conclusion:

According to this meta-analysis, studies showed high heterogeneity, and the prevalence of JH in children and adolescents around the world was equal to 34.1% (95% CI: 33.3%–34.8%) in total, whereas it was higher in girls and lower in older ages.

Exploring the underlying mechanism of pain-related disability in hypermobile adolescents with chronic musculoskeletal pain

OBJECTIVES

A significant proportion of adolescents with chronic musculoskeletal pain (CMP) experience difficulties in physical functioning, mood and social functioning, contributing to diminished quality of life. Generalized joint hypermobility (GJH) is a risk factor for developing CMP with a striking 35-48% of patients with CMP reporting GJH. In case GJH occurs with one or more musculoskeletal manifestations such as chronic pain, trauma, disturbed proprioception and joint instability, it is referred to as generalized hypermobility spectrum disorder (G-HSD). Similar characteristics have been reported in children and adolescents with the hypermobile Ehlers-Danlos Syndrome (hEDS). In the management of CMP, a biopsychosocial approach is recommended as several studies have confirmed the impact of psychosocial factors in the development and maintenance of CMP. The fear-avoidance model (FAM) is a cognitive-behavioural framework that describes the role of pain-related fear as a determinant of CMP-related disability.

CONTENT

Pubmed was used to identify existing relevant literature focussing on chronic musculoskeletal pain, generalized joint hypermobility, pain-related fear and disability. Relevant articles were cross-referenced to identify articles possibly missed during the primary screening. In this paper the current state of scientific evidence is presented for each individual component of the FAM in hypermobile adolescents with and without CMP. Based on this overview, the FAM is proposed explaining a possible underlying mechanism in the relations between GJH, pain-related fear and disability.

SUMMARY AND OUTLOOK

It is assumed that GJH seems to make you more vulnerable for injury and experiencing more frequent musculoskeletal pain. But in addition, a vulnerability for heightened pain-related fear is proposed as an underlying mechanism explaining the relationship between GJH and disability. Further scientific confirmation of this applied FAM is warranted to further unravel the underlying mechanism.In explaining disability in individuals with G-HSD/hEDS, it is important to focus on both the physical components related to joint hypermobility, in tandem with the psychological components such as pain-related fear, catastrophizing thoughts and generalized anxiety.

Muscle strength, muscle power and body composition in college-aged young women and men with Generalized Joint Hypermobility

The aim of this study was an evaluation of the musculoskeletal system in women and men with Generalized Joint Hypermobility (GJH). The study included 87 participants– 40 with Generalized Joint Hypermobility (aged 21.2 ±1.8 years) and 47 (aged 21.0 ±1.3 years) in the control group (CG). The study included the Beighton score, the measurements of body composition, muscle flexibility (Straight Leg Raise test, Popliteal Angle test, Modified Thomas Test), and the measurements of muscle strength and muscle power. T-test and Mann-Whitney U Test were applied to assess the differences between independent groups. The study showed that there were no significant differences (p>.05) in the assessed body composition and the muscle flexibility between both women and men with GJH and the participants in the CG. Under isokinetic conditions for the non-dominant lower extremity, men from the CG received significantly higher (p = .02) flexion peak torque at 180°/s angular velocity. Women from the CG received a statistically significantly lower (p = .04) F/E ratio at 180°/s velocity. Under isometric conditions for both women and men with GJH, there were no statistically significant differences (p>.05) in the maximum torques in knee extension and flexion compared to the CG. For women and men with GJH, the maximum power in the lower extremities and jumping ability were not significantly different (p>.05) compared to the CG participants. The body composition, muscle flexibility, muscle strength, and muscle power of adults with Generalized Joint Hypermobility did not differ compared to healthy participants. The fact that there are no differences does not exclude the efficacy of strength training in increasing levels of muscle strength and its impact on body posture and proprioception or coordination.

Generalized joint hypermobility and perceived harmfulness in healthy adolescents; impact on muscle strength, motor performance and physical activity level

Objective: The first aim of this study was to determine whether adolescents with asymptomatic Generalized Joint Hypermobility (GJH) have a lower level of physical functioning (physical activity level, muscle strength and performance) compared to non-hypermobile controls. Secondly, to evaluate whether the negative impact of perceived harmfulness on physical functioning was more pronounced in adolescents with asymptomatic GJH.Methods: Cross-sectional study. Sixty-two healthy adolescents (mean age 16.8, range 12-21) participated. Hypermobility (Beighton score), perceived harmfulness (PHODA-youth) and muscle strength (dynamometry), motor performance (Single-Leg-Hop-for-Distance) and physical activity level (PAL) (accelerometry) were measured. Hierarchical regression analyses were used to study differences in physical functioning and perceived harmfulness between asymptomatic GJH and non-hypermobile controls.Results: Asymptomatic GJH was associated with increased knee extensor muscle strength (peak torque/body weight; PT/BW), controlled for age and gender (dominant leg; ß = 0.29; p = .02). No other associations between asymptomatic GJH and muscle strength, motor performance and PAL were found. Perceived harmfulness was not more pronounced in adolescents with asymptomatic GJH.Conclusions: Adolescents with asymptomatic GJH had increased knee extensor muscle strength compared to non-hypermobile controls. No other differences in the level of physical functioning was found and the negative impact of perceived harmfulness was not more pronounced in adolescents with asymptomatic GJH.