The effectiveness of fatigue on repositioning sense of lower extremities: systematic review and meta-analysis.

INTRODUCTION: An injury can significantly harm both individual and team performance. One of the most important risk factors for sports-related injuries, especially non-collision injuries, is fatigue. It seems that poor proprioception may play an essential role to impose athletes to further injuries. This systematic review and meta-analysis aimed to examine the effectiveness of fatigue on the repositioning sense of the lower extremity joints. METHOD: The electronic databases, including PubMed, Web of Science, Scopus, and Google Scholar were systematically searched from inception to 11January 2024. The obtained records were exported to the EndNote Software version 8. Then, two investigators examined the records independently to find eligible studies based on the inclusion/exclusion criteria. In the case of disagreements, a consequence method was utilized. The quality of the eligible studies was evaluated using the Downs and Black checklist. Comprehensive Meta-Analysis (CMA) software ver. 3 software was used for statistical analysis. Q-test and I2 were employed to examine the data homogeneity. In addition, considering the risk of bias, the Funnel Plot and trim-and-fill method were used. RESULTS: After reviewing the titles and abstracts of 3883 studies found in the selected databases, 43 articles were found to be eligible to include in meta-analyses. The results showed that fatigue led to a significant increase in the active absolute error of the knee (SDM = 0.524, 95% CI = 0.406-0.841), ankle in the horizontal plane (SDM = 0.541, 95% CI = 0.367-0.715), ankle in the sagittal plane (SDM = 0.443, 95% CI = 0.088-0.798), and hip (SDM = 0.988, 95% CI = 0.135-1.841). However, fatigue had no significant effects on the passive absolute error of the knee and ankle in horizontal plane and relative angular error of the knee. CONCLUSION: Fatigue can diminish the active joint position sense of the lower extremities and thus may increase the risk of injury by reducing proprioception. Therefore, future research could be conducted to investigate the potential impact of integrated fatigue-mitigating exercises into athletes' training programs, with the aim of reducing the incidence of sports-related injuries.

Lower limb muscle activation pattern in male soccer players with lumbar hyperlordosis.

OBJECTIVE: the aim of the current study was to compare the lower limb muscle activation pattern in soccer players with and without lumbar hyperlordosis during single-leg squat performance. METHODS: thirty male collegiate soccer players (15 with and 15 without lumbar hyperlordosis) performed the SLS task. Surface EMG was used to record the activation of eleven lower limb muscles. The activation of these muscles reduces to 100 points during the SLS cycle, where 50% demonstrates the maximum knee flexion, and 0% and 99% demonstrate the maximum knee extension. RESULTS: soccer players with lumbar hyperlordosis had higher muscle activation than those with normal lumbar lordosis in gluteus maximus, biceps femoris, and medial gastrocnemius. By contrast, they had lower gluteus medius, vastus medialis oblique, rectus femoris, soleus, and medial gastrocnemius (only in the final ascent phase of the SLS) muscle activity than the normal group during the SLS. CONCLUSION: this alteration may negatively affect targeted muscle performance during the SLS. Subsequent study is required to specify whether such an alteration in the lower limb muscle could be accompanied by injury in soccer players and change in their athletic performance.

Comparison of postural sway in individuals with and without dynamic knee valgus.

BACKGROUND: Dynamic knee valgus (DKV) is a multi-planar faulty movement pattern that can cause faulty postural control. The primary objective of this study is to investigate the differences in postural sway (PS) between individuals aged 18-30 years old diagnosed with and without DKV. METHODS: In this cross-sectional study, 62 students (39 males and 23 females) with and without DKV (age: 24.58 ± 2.63 years) were selected and assigned to two groups by conducting the single-leg squat test in the screening stage. The Biodex balance system was then employed to compare the two groups in PS. Mann-Whitney U test was conducted to compare the groups in PS (p ≤ 0.05). RESULTS: The study's findings indicate that individuals with DKV did not exhibit any significant differences, compared to those without, about the anterior-posterior stability index (with p values for both static and dynamic situations at 0.309 and 0.198, respectively), medial-lateral stability index (with p values for both static and dynamic situations at 0.883 and 0.500, respectively), and overall stability index (with p values for both static and dynamic situations at 0.277 and 0.086, respectively). CONCLUSION: Though several possible factors could contribute to the lack of significant differences in postural sway between individuals with and without DKV, such as measurement tool differences, variable sensitivity in postural stability tests, and differences in movement variability and test stance, we recommend analyzing postural sway in more functional tasks and with different methodological patterns in future studies. Such research could help develop targeted interventions for individuals with DKV and offer a better understanding of the relationship between postural control and DKV.

Distinctive characteristics of prolonged standing low back pain developers' and the associated risk factors: systematic review and meta-analysis.

Pain developers (PDs) are considered a pre-clinical low back pain (LBP) population at risk of clinical LBP development and thus exacting great social and economic costs. Therefore, it is necessary to comprehensively investigate their distinctive characteristics and the risk factors of standing-induced LBP based on which appropriate preventive measures can be planned. Scopus, Web of Science, and PubMed databases as well as Google Scholar and ProQuest were systematically searched from inception through 14 July 2022 using a combination of terms relevant to 'standing' and 'LBP'. Studies with low risk of bias in English and Persian using a methodological quality scoring system were deemed eligible for inclusion if they were laboratory studies using prolonged standing duration greater than 42 min to classify adult PDs and non-pain developers (NPDs) without a history of LBP. PDs were compared with NPDs in demographics, biomechanical, and psychological outcomes. Weighted or standardized mean differences, and Hedge's g were generated to determine the pooled effect sizes using STATA software version 17. 52 papers and theses involving 1070 participants (528 PDs and 542 NPDs) were eligible for inclusion in the systematic review 33 of which were used in meta-analyses. Significant differences between PDs and NPDs in terms of movement patterns, muscular, postural, psychological, structural, and anthropometric variables were evidenced. The following factors were found to have a statistically significant association with standing-induced LBP: lumbar fidgets (Hedge's g - 0.72, 95% CI - 1.35 to - 0.08, P = 0.03), lumbar lordosis in participants over 25 years (Hedge's g 2.75, 95% CI 1.89-3.61, P < 0.001), AHAbd test (WMD 0.7, 95% CI 0.36-1.05, P < 0.001), GMed co-activation (Hedge's g 4.24, 95% CI 3.18-5.3, P < 0.001), and Pain Catastrophizing Scale (WMD 2.85, 95% CI 0.51-5.19, P = 0.02). Altered motor control displayed in AHAbd test and higher lumbar lordosis in individuals over 25 years seem to be probable risk factors for standing-induced LBP. In order to detect standing-induced LBP risk factors, future researchers should investigate the association of the reported distinctive characteristics to the standing-induced LBP and that whether they are manipulable through various interventions.

The relationship between core muscle endurance and functional movement screen scores in females with lumbar hyperlordosis: a cross-sectional study.

BACKGROUND: Core muscle endurance is essential for proper movement and lower extremity injury prevention. In addition, the Functional Movement Screen (FMS) score is a tool to assess body movement patterns to predict the risk of injury. Although various researches have investigated the relationship between the core muscle endurance and the FMS score, no study has ever assessed the effect of postural deformity on the FMS score. This study investigates the relationship between core muscle endurance and FMS scores in females with lumbar hyperlordosis. METHODS: 42 healthy females aged 24.03 ± 4.4 years with hyperlordosis ( > = 45/66 degrees) participated in this study. Core muscle endurance was assessed by the McGill stability test. Correlations were evaluated between the FMS score, McGill test, and lordosis angle using spearman correlation coefficients (p ≤ 0.05). RESULTS: Most individual FMS scores were not correlated with the McGill test except stability trunk push up. Also, lordosis angle was not correlated with the FMS composite score (r=-0.077; p = 0.631), while it was negatively correlated with the McGill test (r=-0.650; p = 0.000). CONCLUSION: The lack of correlation between the FMS score and the McGill test implies that one's level of core endurance may not influence their functional movement patterns. In contrast, the lumbar lordosis angle might impact one's core muscle endurance but not their functional movement patterns.

Prevalence of idiopathic scoliosis in athletes: a systematic review and meta-analysis.

Objective: This study aimed to determine the prevalence of idiopathic scoliosis (IS) in child, adolescent and adult athletes of all sports activity levels. Design: Systematic review with meta-analysis. Data sources: Electronic databases (PubMed, Scopus, ProQuest, Sage journals, ScienceDirect, Google Scholar and Springer) were systematically searched up from inception to 28 September 2021. Eligibility criteria for selecting studies: Observational investigations were included to evaluate the prevalence of IS in athletes (engaged in any type of individual and team sports). Congenital scoliosis, neuromuscular scoliosis, Scheuermann's kyphosis and de novo scoliosis were not included. The risk of bias was assessed using the tool developed by Hoy et al. Results: Twenty-two studies were included (N=57 470, range 15-46544, participants), thirteen studies were of high-quality. The estimated prevalence of IS in athletes was 27% (95% CI 20% to 35%, I2=98%), with a 95% prediction interval (1% to 69%). The prevalence of IS was significantly higher in female athletes (35%, 95% CI 27% to 34%, I2=98%). Ballet dancers showed a high IS prevalence (35%, 95% CI 24% to 47%, I2=98%). Recreational athletes showed a higher IS prevalence (33%, 95% CI 24% to 43%, I2=98%) than at competitive-level athletes (0.05%, 95% CI 0.03% to 0.08%, I2=98%), followed by elite (20%, 95% CI 13% to 27%, I2=98%). Conclusions: The prevalence of IS in athletes was similar or higher to that as seen in other studies of the general population. IS prevalence may have a U-shaped relationship relative to level of competition. Further studies are required to determine which sports have the highest IS prevalence.

The effectiveness of the comprehensive corrective exercise program on kinematics and strength of lower extremities in males with dynamic knee valgus: a parallel-group randomized wait-list controlled trial.

BACKGROUND: Dynamic knee valgus (DKV) is a prevalent movement impairment widely regarded as a risk factor for lower extremity disorders such as patellofemoral pain syndrome. The present study aimed to investigate the effectiveness of the comprehensive corrective exercise program (CCEP) on kinematics and strength of lower extremities in males with DKV. METHODS: Thirty asymptomatic young men with DKV between the ages of 18 and 28 years participated in this study. They were randomly assigned to the intervention (n = 15) and control groups (n = 15). The intervention group performed the CCEP for three sessions per week for eight weeks, while the control group only did activities of daily living. Hip external rotator and abductor muscle strength and three-dimensional lower extremity kinematics consisting of knee varus/valgus, femur adduction/abduction, femur medial/lateral rotation, and tibial medial/lateral rotation were measured at the baseline and post-test. The data were analyzed using the analysis of covariance (ANCOVA). RESULTS: There were significant improvements in all kinematics variables in the intervention group after the 8-week CCEP. Moreover, the strength of abductor and external rotator muscle improved in the intervention group (P < 0.05). CONCLUSIONS: The CCEP led to substantial improvements in the selected variables of lower extremity kinematics and muscle strength in participants with DKV during a single-leg squat. These results imply that practitioners should adopt a comprehensive approach to pay simultaneous attention to both proximal and distal segments for improving DKV. TRIAL REGISTRATION: The protocol has been approved in the Registry of Clinical Trials (Registration N: IRCT20180821040843N1 ) on 2018-12-30.

The Effects of a Self-Myofascial Release Program on Isokinetic Hamstrings-to-Quadriceps Strength Ratio and Range of Motion of the Knee Joint Among Athletes With Hamstring Shortness.

CONTEXT: Range of motion (ROM) and muscular strength are the main factors that affect athletic performance. Self-myofascial release is a flexibility technique, which is used to inhibit overactive muscle fibers. OBJECTIVE: To investigate the effects of the 8-week self-myofascial release on the isokinetic hamstrings-to-quadriceps strength ratio (H/QRatio) and the ROM of the knee joint among male athletes with the hamstring shortness. DESIGN: A randomized controlled trial. SETTING: Research laboratory. PARTICIPANTS: Twenty-four college-aged male athletes with hamstring shortness were selected for this study and were randomly assigned to a foam rolling group (FOAM, n = 12) and a control group (n = 12). INTERVENTIONS: Participants in the FOAM group performed supervised self-myofascial release program 3 times per week for 8 weeks. The control group received no intervention. METHODS: Data were analyzed via 2-way repeated-measure analysis of variance at the significance level of .05. MAIN OUTCOME MEASURES: ROM and the H/QRatio at the velocities of 60°/s, 120°/s, and 180°/s were measured by an isokinetic dynamometer. RESULTS: The results of 2-way repeated-measure analysis of variance demonstrated that hamstring ROM increased in FOAM group (P = .001). No significant changes were found in H/QRatio after self-myofascial release for FOAM group (P ≥ .05). CONCLUSIONS: When compared with other methods of stretching, self-myofascial release with foam rolling may be beneficial in increasing ROM without decreasing H/QRatio in people with the hamstring shortness.

Can lower extremity anatomical measures and core stability predict dynamic knee valgus in young men?

INTRODUCTION: Dynamic knee valgus (DKV) is a risk factor for lower extremity injuries such as anterior cruciate ligament and patellofemoral pain syndrome. Purpose of the current study was to investigate the relationship between lower extremity anatomical measures (LEAM) and core stability with DKV during the single-leg squat. METHODS: Thirty healthy men aged between 18 and 28 years participated in this cross-sectional biomechanical study.DKV was assessed using a 6-camera motion analysis system during a single-leg squat task. Anteversion of hip, hip internal and external rotation, Q-angle, knee hyperextension, tibial torsion, tibia vara, plantar arch index, and core stability were measured using standard clinical procedures. To predict DKV, a multiple linear regression model was used. RESULT: The stability index negatively and plantar arch index positively predicted greater DKV during the single-leg squat task (P = 0.001 and P = 0.09, respectively). Research variables together predicted 82% of the variance in DKV (F(4,26) = 28.09, p < 0.001). However, relationships between other variables and DKV were not found. CONCLUSION: The core stability index and plantar arch index were associated with observed DKV during the single-leg squat. These results suggested that proximal and distal variables to the knee should be considered when evaluating individuals who present DKV during the single-leg squat.

A comparison of functional movement patterns between female low back pain developers and non-pain developers.

BACKGROUND: Distinctive features of low back pain-developers (LBPDs) as pre-clinical low back pain (LBP) population have been evidenced in three areas of alignment, muscle activation, and movement patterns. To clarify whether the reported altered functional movement patterns in chronic LBP patients result from or result in LBP disorders, LBPDs' functional movement patterns should be investigated. OBJECTIVES: This study aimed to compare female LBPDs' functional movement patterns with non-pain developers' (NPDs). METHODS: Sixty female LBPDs and NPDs were recruited based on the research requirements. The Functional Movement Screen (FMS) was used to investigate movement quality. Data were compared between groups via Mann-Whitney U tests and correlation analyses examined association between pain intensity and onset during prolonged standing and the FMS score. Receiver Operating Characteristic Curves and Chi Squares were conducted to find the best cutoff points. An alpha level of p≤0.05 was used to establish statistical significance. RESULTS: LBPDs scored significantly lower, or rather worse than NPDs in the FMS composite score (12.06±1.33 vs. 16.43±1.59, U = 3, P < 0.001). Moreover, the optimal cutoff scores of≤14 on the FMS, 2 on the push-up, and 1 on the deep squat discriminated between female LBPDs and NPDs. The FMS composite score was correlated negatively with LBP intensity (r (60) = -0.724, p < 0.001) and positively with LBP onset (r (60) = 0.277, p = 0.032) during prolonged standing. Finally, the results indicated that female LBPDs presented with at least one bilateral asymmetry on the FMS had 10 times (95% CI, 2.941-34.008) and with at least two bilateral asymmetries on the FMS had 15.5 times (95% CI, 3.814-63.359) higher odds of developing LBP during prolonged standing than NPDs. CONCLUSIONS: Female LBPDs, who are at higher risk for developing LBP in the future, have significantly lower quality of functional movement patterns compared to NPDs. Moreover, the FMS appears to show promise for predicting individuals who are at risk for LBP development during prolonged standing.

Comprehensive corrective exercise program improves alignment, muscle activation and movement pattern of men with upper crossed syndrome: randomized controlled trial.

Upper crossed syndrome (UCS) refers to the altered muscle activations and movement patterns in scapulae along with some abnormal alignment in the upper quarter, which may contribute to the dysfunction of the cervicothoracic and glenohumeral joints. The present study aimed to investigate the effectiveness of a comprehensive corrective exercise program (CCEP) and subsequent detraining on alignment, muscle activation, and movement pattern in men with the UCS. This randomized controlled trial included 24 men. The intervention group conducted CCEP (8 weeks), followed by four weeks of detraining and the control group maintained normal daily activities. Electromyography of selected muscles, scapular dyskinesis test, head, shoulder, and thoracic spine angle were measured at baseline, post-test, and follow-up. There were significant differences for Group x time interaction and also for within-group from pre-test to post-test and follow-up in all outcomes. Also, significant differences were observed in three outcomes at post-test and follow-up between the CCEP and control group in favor of the CCEP. In Conclusion, the present study demonstrates that the CCEP for individuals with UCS is feasible and effective, improving muscle activation imbalance, movement patterns, and alignment. Importantly, these improvements were maintained after four weeks of detraining, suggesting lasting neuromuscular re-training adaptations.

The effectiveness of a comprehensive corrective exercises program and subsequent detraining on alignment, muscle activation, and movement pattern in men with upper crossed syndrome: protocol for a parallel-group randomized controlled trial.

BACKGROUND: Upper crossed syndrome (UCS) refers to specific altered muscle activation and changed movement patterns along with some postural deviations in the upper quarter of the body. This syndrome might contribute to the dysfunction of the cervicothoracic and glenohumeral joints. OBJECTIVES: The present study will aim to investigate the effectiveness of a comprehensive corrective exercises program (CCEP) and subsequent detraining on alignment, muscle activation and movement pattern in men with UCS. METHODS/DESIGN: This is a parallel-group randomized controlled trial. Participants will be 22 men aged 18 to 28 years who are suffering from UCS. Participants in the intervention group will conduct CCEP (three times a week for 8 weeks), followed by 4 weeks of detraining. The control group will do their daily activities. Participants will be randomized (1:1) into the intervention or the control group. The primary outcome will be upper trapezius activations. Secondary outcomes consist of electromyography of middle and lower trapezius and serratus anterior muscles, scapular dyskinesis test, forward head and shoulder angles, thoracic kyphosis angle, and neck flexion pattern test. DISCUSSION: We propose to evaluate the effectiveness of a randomized controlled trial of a CCEP in men with UCS on their alignment, selected muscle activations, and relevant movement patterns. Results from our trial may provide new insights into the effects of exercise not only on the alignment but also on muscle activation and movement patterns that are important outcomes for people with postural malalignments and, if successful, could assist therapists in evidence-based clinical decision-making. TRIAL REGISTRATION: Iranian Registry of Clinical Trials, IRCT20181004041232N1. Registered on 26 October 2018.

Differences in Gluteal and Quadriceps Muscle Activation Among Adults With and Without Lumbar Hyperlordosis.

CONTEXT: Many factors have been reported contributing to altering the neuromuscular function of hip and knee muscles. The lumbar hyperlordosis, as a poor posture in some athletes, is thought to be associated with the alteration of the hip and knee muscles activity. OBJECTIVE: To examine the activation of selected hip and knee muscles in athletes with and without lumbar hyperlordosis during functional activities. DESIGN: Case-control study. SETTING: University laboratory. PARTICIPANTS: Twenty-six college male athletes (n = 13 with and n = 13 without lumbar hyperlordosis). INTERVENTIONS: Surface electromyography of gluteus maximus (GMAX), gluteus medius (GMED), vastus medialis oblique (VMO), and vastus lateralis (VL) were recorded during single-leg squat and single-leg jump landing (SLJL) tasks. MAIN OUTCOME MEASURE: Preactivity; reactivity; and onset muscle during SLJL and eccentric activity during single-leg squat (GMAX, GMED, VMO, and VL along with the ratio of VMO:VL) were assessed. RESULTS: Athletes with lumbar hyperlordosis had a higher level of activity in their GMAX (P = .003), VMO (P = .04), and VL (P = .01) muscles at the moment before foot contact during SLJL. These athletes also demonstrated a higher level of GMAX activity (P = .01) immediately after foot contact. Finally, athletes with lumbar hyperlordosis activated their GMAX sooner (P = .02) during the SLJL. Athletes with normal lumbar lordosis had more activity in their GMED muscle (P = .001) in the descending phase of the single-leg squat task and a higher VMO:VL (P = .01) at the moment after the foot contact during the SLJL. CONCLUSION: The altered activation of GMAX, GMED, VMO, VL, and VMO:VL can reveal the role of lumbar hyperlordosis in the knee and hip muscles' alteration in athletes. Further study is needed to identify whether these alterations in the hip and knee muscles contribute to injury in athletes.

Musculoskeletal pain in multiple body sites and work ability in the general working population: cross-sectional study among 10,000 wage earners.

Background and aims Musculoskeletal pain may negatively affect work ability, especially when work demands are high and/or physical capacity of the worker is low. This study investigated the association between intensity of musculoskeletal pain in multiple body regions and work ability among young and old workers with sedentary and physical demanding jobs. Methods Currently employed wage earners (n=10,427) replied to questions about pain intensity, work ability, and physical work demands. The odds ratio (OR) for having a lower level of work ability in relation to the physical demands at work were modeled using logistic regression controlled for various confounders. Results The OR for lower work ability increased with higher pain intensity in all regions among workers with sedentary and physical work. The same pattern was observed among workers <50 years and ≥50 years in both work types. The association was quite consistent across age and work activity groups, although it tended to be more pronounced among those with physically demanding work in some of pain regions. Conclusions This study shows that increasing pain intensity in multiple sites of the body is associated with lower work ability. This was seen for both younger and older workers as well as those with sedentary and physical work. Implications Physical workers with multiple-site pain may especially be at increased risk of the consequences of reduced work ability. Therefore, extra attention is needed and this group may benefit from better targeted preventive measures.

Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements by flexible curve.

BACKGROUND AND OBJECTIVE: The amount of postural sway and sagittal deviation of lumbar lordosis angle in measurements of standing lumbar curvature obtained by flexible curve can be decreased when using a spine stabilizer instrument. However, this assumption has not been investigated so far. This study aims to determine the effect of using a spine stabilizer instrument on the validity, reliability, and standard errors of measurement of flexible curve in the standing lumbar curvature measurements. MATERIAL AND METHOD: Thirty-four volunteer men aged between 19 and 30 years participated in the study By using a 50-cm flexible curve, with and without spine stabilizer instrument, and a lumbar simple lateral radiograph (LSLR), the standing lumbar curvature was measured by three methods for each subject. These methods were called A, B and C, respectively. RESULTS: By using the Pearson's correlation analysis at significance level of 0.05, the coefficient of correlation between standing lumbar curvature measurements in methods A and B with C were 0.95 and 0.84, respectively. In addition, the intraclass correlation coefficient for methods A and B were 0.94 and 0.79, respectively. Also, results of the one-way analysis of variance for comparison of pairs indicated a significant difference in the mean values of standing lumbar curvature angles between methods B and C. CONCLUSIONS: Results indicated the flexible curve was an appropriate instrument for standing lumbar curvature measurements. Using spine stabilizer instrument to control postural sway increases the validity and reliability of flexible curve method and decreases its standard errors of measurement.

The efficiency of corrective exercise interventions on thoracic hyper-kyphosis angle.

BACKGROUND AND OBJECTIVE: Corrective exercise interventions are often utilized to manage subjects with thoracic hyper-kyphosis, yet the quality of evidence that supports their efficiency is lacking. In this study, the efficacy of local and comprehensive corrective exercise programs (LCEP and CCEP) on kyphosis angle was evaluated. MATERIAL AND METHOD: A prospective, randomised controlled design was used in the present study. Sixty patients with postural hyper-kyphosis deformity (⩾ 42°) entered the study for 12 weeks. Subjects were randomly assigned to a LCEP (n=20), CCEP (n=20), or Control groups (n=20). Pre- and post-participation levels of kyphosis angle were measured by flexicurve ruler. RESULTS: Both the LCEP and CCEP groups demonstrated statistically significant reductions in thoracic kyphosis angle compared to the control group (p=0.001). Furthermore, based on Cohen's d-value, the efficiency of CCEP was larger than LCEP. CONCLUSIONS: Considering the extremely large effect size of the CCEP, we recommend that this program be used in the correction of postural hyper-kyphosis deformity in future.