Trunk Strength Research Articles

Practicable performance-based outcome measures of trunk muscle strength and their measurement properties: A systematic review and narrative synthesis.

IntroductionThe evaluation of muscle strength is frequently used as part of the physical examination process, with decreased trunk muscle strength reported in individuals with spinal disorders (e.g., low back pain). Access to practicable performance-based outcome measures (PBOM) to monitor patients’ progress in spinal rehabilitation is essential. Knowledge of the psychometric properties of the available practicable PBOM for trunk strength evaluation is therefore needed to inform practitioners and further research.ObjectiveTo synthesise evidence on the measurement properties of practicable measures of trunk muscle strength in adults with and without musculoskeletal pain.MethodsFollowing a published and registered protocol [PROSPERO CRD42020167464], databases were searched from the database inception date up to 30th of June 2021. Citations and grey literature were also searched. Eligibility criteria comprised: 1) studies which examined the psychometric properties of the trunk strength outcome measures, 2) included adults ≥ 18 years, either asymptomatic or with spinal musculoskeletal pain. Non-English language studies were excluded. Two independent reviewers evaluated the quality and synthesized the data from included studies according to the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist. The overall quality of evidence was evaluated using a modified Grading of Recommendations Assessment Development and Evaluation (GRADE).ResultsFrom 34 included studies, 15 different PBOMs were identified that have been investigated for reliability and validity, none evaluated responsiveness. In asymptomatic individuals, high quality evidence supports intra-rater reliability of digital-loading cells and moderate quality evidence supports the criterion validity of the hand-held dynamometer. Very low quality evidence exists for the reliability and validity estimates of testing tools among individuals with spinal pain.ConclusionsFindings underpin a cautious recommendation for the use of practicable PROMs to evaluate muscle strength in individuals with spinal pain in clinical practice due to the level of evidence and the heterogeneity of the protocols used. Further high quality research to explore the psychometric properties of the practicable PBOMs with detailed methodology is now needed.

Seated Outcome Measures in Children With Duchenne Muscular Dystrophy.

Quantifiable motor strength measures to assess disease severity throughout the continuum of Duchenne muscular dystrophy (DMD) are needed. To study the feasibility of seated trunk strength using hand-held dynamometry (HHD) and caregiver-reported subjective functional independence measures in boys with DMD. Prospective, cross-sectional, observational study of 18 participants with DMD enrolled from pediatric muscular dystrophy clinic during routine clinical assessment. Hand-held dynamometry, seated reach distance test and Pediatric Evaluation of Disability Inventory (PEDI) were administered. All study participants regardless of the walking status were able to complete the seated function tests demonstrating feasibility. The age of the participants correlated negatively with PEDI mobility and positively with HHD extension scores. The seated measures did not statistically correlate with PEDI mobility scores. Seated motor strength measures and PEDI mobility scores are feasible. The PEDI mobility and HHD extension scores correlate with age. Study limitations included single-center experience and cross-sectional data. https://www.dropbox.com/s/s4r0k7o6s0tfbkb/PT-Seated-Measures-And-DMD-2022.mp4?dl=0.

Trunk Neuromuscular Function and Anterior Cruciate Ligament Injuries: A Narrative Review of Trunk Strength, Endurance, and Dynamic Control

ABSTRACT Trunk strength, endurance, and dynamic control may have an effect on anterior cruciate ligament (ACL) injury rates and biomechanical ACL loading variables during athletic tasks. Individuals responsible for training athletes at risk of ACL injuries should implement training programs that address these components of athletic performance. In ski racers, deficits in trunk flexion/extension strength and decreased trunk flexion/extension strength ratios have been identified as ACL injury risk factors. Trunk strength training alone is not sufficient to decrease biomechanical ACL loading, and there is no clear association between trunk endurance and ACL injury risks. Trunk dynamic control training may improve trunk and knee movements associated with decreased ACL loading during athletic tasks. Dynamic, unanticipated, and perturbed trunk functional assessments and training are recommended to challenge the trunk more during athletic tasks. Injury prevention programs should involve exercises using unstable surfaces, sports-related dual tasks, and perturbations to address trunk dynamic control. More investigation is still needed to further understand the associations between trunk neuromuscular functions and ACL injury risks during athletic tasks.

Single- and Multi-Joint Maximum Weight Lifting Relationship to Free-Fat Mass in Different Exercises for Upper- and Lower-Limbs in Well-Trained Male Young Adults.

This study aimed to analyze whether the relationship between regional and whole-body fat-free mass (FFM) and strength is related to FFM distribution and area according to limb involvement. Thirty well-trained male young adults underwent one-repetition maximum test (1RM) to assess the strength in arm curl (AC), bench press (BP), seated row (SR), leg press 45° (LP45), knee extension (KE), and leg curl (LC). Dual-energy X-ray absorptiometry was used to evaluate FFM. The values for 1RM in AC, BP, and R correlated to FFM in upper limb (R2 = 0.69, 0.84 and 0.75), without an effect of appendicular mass index (API) or area. For 1RM in KE, the correlation with FFM in lower limb increased with thigh area (R2 = 0.56), whereas 1RM in LC and LP45 correlation to whole-body FFM increased with API (R2 = 0.64 and 0.49). The upper limb’s FFM may be reliable for indexing the arms and upper trunk strengths, whereas the relationships between FFM and strength in lower limb improve as muscle mass and thigh area increases between subjects.

Effect of Six-Week Resistance and Sensorimotor Training on Trunk Strength and Stability in Elite Adolescent Athletes: A Randomized Controlled Pilot Trial.

Intervention in the form of core-specific stability exercises is evident to improve trunk stability. The purpose was to assess the effect of an additional 6 weeks sensorimotor or resistance training on maximum isokinetic trunk strength and response to sudden dynamic trunk loading (STL) in highly trained adolescent athletes. The study was conducted as a single-blind, 3-armed randomized controlled trial. Twenty-four adolescent athletes (14f/10 m, 16 ± 1 yrs.;178 ± 10 cm; 67 ± 11 kg; training sessions/week 15 ± 5; training h/week 22 ± 8) were randomized into resistance training (RT; n = 7), sensorimotor training (SMT; n = 10), and control group (CG; n = 7). Athletes were instructed to perform standardized, center-based training for 6 weeks, two times per week, with a duration of 1 h each session. SMT consisted of four different core-specific sensorimotor exercises using instable surfaces. RT consisted of four trunk strength exercises using strength training machines, as well as an isokinetic dynamometer. All participants in the CG received an unspecific heart frequency controlled, ergometer-based endurance training (50 min at max. heart frequency of 130HF). For each athlete, each training session was documented in an individual training diary (e.g., level of SMT exercise; 1RM for strength exercise, pain). At baseline (M1) and after 6 weeks of intervention (M2), participants’ maximum strength in trunk rotation (ROM:63°) and flexion/extension (ROM:55°) was tested on an isokinetic dynamometer (concentric/eccentric 30°/s). STL was assessed in eccentric (30°/s) mode with additional dynamometer-induced perturbation as a marker of core stability. Peak torque [Nm] was calculated as the main outcome. The primary outcome measurements (trunk rotation/extension peak torque: con, ecc, STL) were statistically analyzed by means of the two-factor repeated measures analysis of variance (α = 0.05). Out of 12 possible sessions, athletes participated between 8 and 9 sessions (SMT: 9 ± 3; RT: 8 ± 3; CG: 8 ± 4). Regarding main outcomes of trunk performance, experimental groups showed no significant pre–post difference for maximum trunk strength testing as well as for perturbation compensation (p > 0.05). It is concluded, that future interventions should exceed 6 weeks duration with at least 2 sessions per week to induce enhanced trunk strength or compensatory response to sudden, high-intensity trunk loading in already highly trained adolescent athletes, regardless of training regime.

Hip Extensor Strength Influences Dynamic Postural Changes during Gait in Patients with Adult Spinal Deformity: A Cross-Sectional Study Using Three-Dimensional Motion Analysis.

Single-hospital cross-sectional study. The aim of the present study was to investigate the physical functions influencing dynamic postural change in patients with adult spinal deformity (ASD). Dynamic postural change leading to increased forward lean during gait is a problem in patients with ASD; however, the relationship between this change and trunk and hip extensor strength is unclear. Thirty patients with ASD aged ≥50 years who were admitted to our hospital between July 2016 and September 2019 were included in this study. X-ray parameters (i.e., sagittal vertical axis, pelvic tilt, and pelvic incidence minus lumbar lordosis) were evaluated from the full-length standing radiographs of the subjects. Trunk and hip extensor strength was evaluated using a hand-held dynamometer. Dynamic postural changes (i.e., sagittal trunk shift during standing, sagittal trunk shift during gait, and delta sagittal trunk shift) were assessed using a three-dimensional motion analysis system. The relationships between dynamic postural change and various X-ray parameters, as well as trunk and hip extensor strength, were examined using multivariable analysis. Multivariable analysis showed that hip extensor strength is the factor most strongly associated with dynamic postural change among the X-ray parameters and physical functions assessed in this study (β=-0.41, R2=0.12). We demonstrated the association between dynamic postural change and hip extensor strength in patients with ASD. Our results may be useful to healthcare providers treating patients with ASD. Interventions for dynamic postural change in patients with ASD should focus on hip extensor strength.

Correlation between upper limb function and clinical measures of shoulder and trunk mobility and strength in overhead athletes with shoulder pain

ObjectiveTo investigate the correlation between functional performance and self-reported upper limb function and between these two functional measures and clinical measures of shoulder and trunk in overhead athletes with shoulder pain. DesignCross-sectional study. SettingsLaboratory. ParticipantsTwenty-one volleyball and handball athletes (23.6 ± 3.7 years) with shoulder pain in the dominant limb. Main outcome measuresSelf-reported dominant upper limb function using Penn Shoulder Score and Disabilities of the Arm, Shoulder, and Hand; shoulder and trunk range of motion; isometric strength of shoulder, periscapular, and trunk muscles; endurance time of trunk muscles; and functional upper limb performance using the Upper Quarter Y-Balance Test (UQYBT). ResultsA moderate correlation was observed (r = 0.45–0.58; p < 0.05) between UQYBT performance and strength of serratus anterior, lower trapezius, trunk rotators, and trunk flexors. No significant correlation was observed between UQYBT performance and the other clinical measures of shoulder and trunk (r = 0.01–0.39, p > 0.05). Self-reported upper limb function was neither significantly correlated with clinical measures (r = 0.01–0.40, p > 0.05) nor with UQYBT performance (r = 0.02–0.19, p > 0.05). ConclusionWe observed a correlation between UQYBT performance and strength of periscapular and trunk muscles.

Axial muscle involvement in patients with limb girdle muscular dystrophy type R9

Limb girdle muscular dystrophy type R9 (LGMDR9) is characterized by progressive weakness of the shoulder and hip girdles. Involvement of proximal extremity muscles is well-described whereas information about axial muscle involvement is lacking. It is important to recognize the involvement of axial muscles to understand functional challenges for the patients. The aim of this study was to investigate the involvement of axial and leg muscles in patients with LGMDR9. This observational, cross-sectional study investigated fat replacement of axial and leg muscles in 14 patients with LGMDR9 and 13 matched, healthy controls using quantitative MRI (Dixon technique). We investigated paraspinal muscles at three levels, psoas major at the lumbar level, and leg muscles in the thigh and calf. Trunk strength was assessed with stationary dynamometry and manual muscle tests. Patients with LGMDR9 had significantly increased fat replacement of all investigated axial muscles compared with healthy controls (P < .05). Trunk extension and flexion strength were significantly reduced in patients. Extension strength correlated negatively with mean fat fraction of paraspinal muscles. Fat fractions of all investigated leg muscles were significantly increased versus controls, with the posterior thigh muscles being the most severely affected. Patients with LGMDR9 have severe involvement of their axial muscles and correspondingly have reduced trunk extension and flexion strength. Our findings define the axial muscles as some of the most severely involved muscle groups in LGMDR9, which should be considered in the clinical management of the disorder and monitoring of disease progression.

Motor skill training versus strength and flexibility exercise in people with chronic low back pain: Preplanned analysis of effects on kinematics during a functional activity

BackgroundPeople with chronic low back pain display the altered movement pattern where the lumbar spine moves more readily into its available range of motion relative to other joints. A logical approach to treatment, therefore, would be to improve this pattern during functional activities. Methods154 participants were randomized to receive 6 weeks of motor skill training or strength and flexibility exercise. Participants in the motor skill training group received person-specific training to modify their altered movement pattern during functional activities. Participants in the strength and flexibility group received exercises for trunk strength and trunk and lower-limb flexibility. At baseline, post-treatment and 6-months after treatment participants performed a test of picking up an object using their preferred pattern. Three-dimensional marker co-ordinate data were collected. A mixed-model repeated measures analysis of variance was used to examine the treatment group and time effects. FindingsMotor skill training: Baseline early excursion values [mean (confidence interval)] were as follows: knee = 11.1°(8.0,4.1), hip = 21.2°(19.2,23.1), lumbar = 11.3°(10.4,12.3). From baseline to post-treatment significant improvements in early excursion included: knee = +18.6°(15.4,21.8), hip = +10.8°(8.8,12.8), and lumbar = −2.0°(−0.1,-4.0). There were no significant changes from post-treatment to 6-month follow-up. Strength and flexibility exercise: Baseline early excursion values were as follows: knee = 8.9°(5.8,11.9), hip = 20.8°(18.9,22.8), and lumbar = 11.2°(10.3,12.2) early excursion. There were no significant changes for knee, hip, and lumbar early excursion. InterpretationMotor skill training was more effective than strength and flexibility exercise at changing and maintaining change to the altered movement pattern during a functional activity test of picking up an object.

Feasability of An Eccentric Isokinetic Protocol to Induce Trunk Muscle Damage: A Pilot Study.

Eccentric exercise is discussed as a treatment option for clinical populations, but specific responses in terms of muscle damage and systemic inflammation after repeated loading of large muscle groups have not been conclusively characterized. Therefore, this study tested the feasibility of an isokinetic protocol for repeated maximum eccentric loading of the trunk muscles. Nine asymptomatic participants (5 f/4 m; 34±6 yrs; 175±13 cm; 76±17 kg) performed three isokinetic 2-minute all-out trunk strength tests (1x concentric (CON), 2x eccentric (ECC1, ECC2), 2 weeks apart; flexion/extension, 60°/s, ROM 55°). Outcomes were peak torque, torque decline, total work, and indicators of muscle damage and inflammation (over 168 h). Statistics were done using the Friedman test (Dunn’s post-test). For ECC1 and ECC2, peak torque and total work were increased and torque decline reduced compared to CON. Repeated ECC bouts yielded unaltered torque and work outcomes. Muscle damage markers were highest after ECC1 (soreness 48 h, creatine kinase 72 h; p<0.05). Their overall responses (area under the curve) were abolished post-ECC2 compared to post-ECC1 (p<0.05). Interleukin-6 was higher post-ECC1 than CON, and attenuated post-ECC2 (p>0.05). Interleukin-10 and tumor necrosis factor-α were not detectable. All markers showed high inter-individual variability. The protocol was feasible to induce muscle damage indicators after exercising a large muscle group, but the pilot results indicated only weak systemic inflammatory responses in asymptomatic adults.

Isometric Trunk Strength Assessment of Athletes: Effects of Sex, Sport, and Low Back Pain History.

The importance of isometric trunk strength (ITS) among sport science professionals is higher than its actual reported effect size on either performance or low back pain (LBP) occurrence. To provide normative values of ITS and strength ratios, and to evaluate the effect of sex, sports discipline, and LBP status. Crossover study. University research laboratory. Five hundred and sixty-seven elite athletes (186 females) with and without a history of LBP from different sports. Participants underwent ITS testing for trunk flexors, extensors, and lateral flexors. Normalized maximal strength (in newton meter per kilogram) and strength ratios were calculated. Differences between sex, LBP, and sport disciplines were assessed with 3-way analysis of variance (sex × LBP status × 7 sport categories) and partial eta-squared (ηp2) effect size. The predictive validity of ITS for LBP was checked with receiver operating characteristics (area under the curve). The authors found significant differences in extensor and flexor ITS in favor of male athletes (medium ηp2, P < .05), while sex differences in lateral flexion ITS had a low size effect (P < .05). A low size effect was also observed for the differences in strength ratios extensors/flexors (mean 1.47; 95% confidence interval, 1.45-1.50) and left flexors/right flexors (mean 0.99; 95% confidence interval, 0.98-1.01) among sexes. The sport discipline-related differences generally had a low size effect. No significant differences in ITS were found between LBP and LBP-free athletes. Only 50% to 58% of athletes (area under the curve, 0.501-0.582) were correctly classified as LBP or LBP-free using different ITS and strength ratio variables. ITS and strength ratios have low predictive validity for LBP history but may discriminate between sex and sport disciplines. Our data are a useful reference point for meaningful individual results interpretation when athletes are evaluated during training or rehabilitation.

Specific Fitness Profiles through Analysis of the Correlation between Anaerobic Power, Maximal Strength, and Isokinetic Strength in Korean National Snowboarders

Purpose: We examined the associations between anaerobic power, maximal strength, and isokinetic strength in Korean National snowboarders. Methods: We examined cross-sectional associations between isokinetic trunk strength in 89 Korean National snowboarders (mean age: 22.17 ± 4.82 years). The main outcome measures were the Wingate anaerobic power test, maximal strength test, and isokinetic knee strength test. Results: Isokinetic trunk strength was correlated with anaerobic power (lower average power, peak power, and power-drop rate). Further, trunk strength flexion and extension were significantly associated with maximal strength (knee strength and one-repetition maximum). Conclusions: The Korean national snowboarders’ anaerobic capacity and maximal muscle strength measurements were positively associated with their isokinetic trunk strength. Further research is needed to elucidate the core balance and muscle-growth mechanisms underlying this association; ideally, future studies will involve exercise and treatment interventions to identify causal relationships.

Effects of aquatic therapy on people with osteopenia or osteoporosis: A systematic review

Background Aquatic exercises have been widely used to treat people with osteopenia and osteoporosis (OP), claiming that they may improve balance; nonetheless, there is still controversy on its use for this population. Objectives To investigate the effects of aquatic exercise (AE) on people with osteopenia or OP. Methods Systematic review that included clinical trials, with at least one AE group and a control group. The electronic databases PubMed, EMBASE, Cochrane, Scopus and Web of Science were searched. The risk of bias assessment was performed independently by two reviewers with the Revised Cochrane risk-of-bias tool for randomized trials (RoB 2). Results A total of 1793 articles were identified, and 7 articles were considered eligible, mostly considered as of low risk of bias. The total sample size was composed of 562 women (mean ages between 58.6 ± 6.7 and 73.3 ± 3.9). The interventions were supplementation, pharmacological treatment and protocols both of land-based exercises (LE) and AE. Outcomes were quality of life, functionality, balance, function, mobility, handgrip, lower limbs and trunk strength, flexibility and pain, with controversial results on all variables. Conclusions Even though AE seem to be beneficial for people with osteopenia or OP, protocols for evaluation and treatment are heterogeneous and did not allow a meta-analysis computation. As such, it was not possible to conclude if AE are beneficial to people with osteopenia or OP. Trial Registration This systematic review was registered in the international prospective register of systematic reviews (PROSPERO [OMITTED FOR BLINDING PURPOSES]).

Effect of 12 Weeks Core Training on Core Muscle Performance in Rhythmic Gymnastics.

Simple SummaryThe aim of this study was to analyze the effect of 12 weeks of core muscle training on core muscle performance in rhythmic gymnasts. Core strength training leads to improvements in body composition, as well as improvements in trunk strength and increases in muscle electromyographic activity. These improvements could therefore improve performance during competitive rhythmic gymnastics exercises.Background: Rhythmic gymnastics performance is characterized by technical elements involving flexibility, aerobic capacity and strength. Increased core strength in rhythmic gymnastics could lead to improved sporting performance. Objective: The aim of this study was to analyze the effect of 12 weeks of core muscle training on core muscle performance in rhythmic gymnasts. Methods: A randomized controlled study involving 24 rhythmic gymnastics was conducted. Participants were randomly assigned to a control group (CG; n = 12; age 13.50 ± 3.17 years) or a training group (TG; n = 12; age 14.41 ± 2.35 years). Body composition, isometric strength of trunk, core endurance and core muscle electromyographic activity were measured (EMG) after 12 weeks of core training. Independent sample t-tests were carried out to compare baseline values between groups. A two-way repeated-measures analysis of variance (ANOVA) (time × group) was applied. Results: The TG improved body composition, trunk lean mass (mean differences MD = −0.31; p = 0.040), lean mass (MD = 0.43; p = 0.037) and bone mass (MD = −0.06; p < 0.001) after training. Core training increased isometric strength of trunk, flexion test (MD = −21.53; p = 0.019) and extension test (MD = 22.7; p = 0.049), as well as the prone bridge core endurance test (MD = −11.27; p = 0.040). The EMG values also increased in the TG in prone bridge for front trunk (MD = −58.58; p = 0.026). Conclusions: Core strength training leads to improvements in body composition, as well as improvements in trunk strength and increases in muscle electromyographic activity. These improvements could therefore improve performance during competitive rhythmic gymnastics exercises.

Gender-based Variations in Trunk Motion and Isometric Strength in Young Adults with Low Back Pain: A Prospective Case-control Study.

Objective To determine gender-based variations in trunk range of motion (RoM) and isometric strength (IS) in symptomatic and asymptomatic young adults. Methods In this prospective case-control study, 73 subjects with low back pain (LBP) and 80 asymptomatic subjects were analyzed. Dynamometer-based device trunk RoM and IS measurements in extension, flexion, and rotation were compared in both groups and gender-based subgroups. Multivariate analysis was used to determine factors influencing trunk RoM and IS. Results Symptomatic males had significantly less extension RoM and extension, flexion, and rotation isometric trunk strength (ITS) ( p < 0.0001) compared with asymptomatic males, whereas no significant difference was found between asymptomatic and symptomatic females. However, the mean extension-flexion RoM and mean extension-flexion ITS ratios were significantly lower ( p = 0.04) in asymptomatic females compared with symptomatic females. Female gender was significantly associated with less extension and flexion ITS in both asymptomatic and symptomatic subjects. Conclusion Males with LBP had significant global ITS weakness when compared with asymptomatic males. Despite no significant ITS difference in symptomatic versus asymptomatic females, LBP caused significant extension-flexion RoM and ITS imbalance in females. These gender-based variations in trunk RoM and IS, especially the extensor-flexor IS imbalance in females, must be considered while designing rehabilitation treatment protocols for LBP.

Relationships between trunk morphology and strength with non-contact lower limb injuries in elite rugby league and Australian football players

Background: Non-contact lower limb injuries (NCLLI) are common within the National Rugby League (NRL) and Australian Football League (AFL). Smaller lumbar multifidus at L5 (LM L5) cross-sectional area (CSA) and lower levels of trunk and hip extension and knee flexion strength have been associated with increased NCLLI risk in AFL players. However, such associations have not been reported in the NRL. This study aims to explore relationships between NCLLI, trunk morphology and isometric trunk and hip extension strength in NRL and AFL players. Methods: NRL and AFL players had their LM L2-L5 and quadratus lumborum (QL) CSA (n=238), and isometric trunk and hip extension strength (n=153) measured using ultrasonography and a novel field-based test in preseason. Isometric trunk and hip extensor strength were measured using a 65s maximal voluntary isometric contraction (MVIC) protocol (5s MVIC, 5s off, 45s MVIC, 5s off, 5s MVIC). Team medical staff reported all NCLLIs sustained in the subsequent competitive season. The associations between LM and QL CSA, 5s and 45s MVIC, age, and previous injury, and prospectively occurring NCLLI were analysed using univariable and then multivariable logistic regression. Logistic regression analysis was also performed for the most sustained NCLLI (hamstring and knee). Results: Seventy-two players sustained a NCLLI in the 2020 competitive seasons (51 NRL, 21 AFL). From univariable logistic regression previous injury increased the risk of any NCLLI in NRL (OR=2.43, 95%CI=1.16-5.09, p=0.019). Reduced 5s MVIC (OR=1.00, 95%CI=1.00-1.01, p=0.012), increased QL CSA (OR=1.55, 95%CI=1.05-2.38, p=0.033) and lower ratio between LM and QL CSA (OR=0.03, 95%CI=0.01-0.60, p=0.02) increased NCLLI risk in AFL. Pooled hamstring injuries (n=28) were most common and were associated with lower 5s MVIC (OR=0.99, 95%CI=0.99-1.00, p=0.02) and 45s MVIC (OR=0.99, 95%CI=0.99-1.00, p=0.001). Pooled knee injuries (n=21) were associated with both reduced LM CSA (OR=1.35, 95%CI=1.08-1.70, p=0.018) and LM to QL ratio (OR=3.62, 95%CI=1.41- 9.66, p=0.043). Conclusions: Larger QL CSA and reduced levels of trunk and hip extension strength are observed in AFL players in preseason who sustain a NCLLI in the subsequent playing season. Only previous NCLLI was associated with future risk of NCLLI for NRL players. These results suggest that risk factors for NCLLI are football code specific, and prevention strategies should be tailored accordingly. Conflict of interest statement: My co-authors and I acknowledge that we have no conflict of interest relevant to the submission of this abstract.

Effects of stabilization exercises on disability, pain, and core stability in patients with non-specific low back pain: A randomized controlled trial

BACKGROUND: Many studies have emphasized the importance of stabilization exercises (SE) for the management of non-specific low back pain (NSLBP), yet there is no study assessing all aspects of core stability in comparing SE and other exercises. OBJECTIVE: To investigate the effects of SE on pain and core stability by using core stability tests that focus on all aspects of core stability in patients with NSLBP. METHODS: Thirty-seven individuals with chronic NSLBP were randomly divided into two groups as SE and conventional exercises (CE). Both groups underwent the progressive exercise program three days per week for six weeks. The assessments were conducted before and after the exercise programs. The outcome measures included pain, disability, trunk strength, trunk flexor, extensor and lateral flexor endurance, function, flexibility, and motor control during eyes open/closed. RESULTS: All assessment parameters except motor control during eyes open improved after SE (p &lt; 0.05). Also, all assessment parameters except motor control during eyes open/closed and lateral trunk endurance improved after CE (p &lt; 0.05). When comparing groups for gain scores, there were more significant improvements in pain during activity, endurance and function after SE (p &lt; 0.05). CONCLUSIONS: SE is more effective than CE in reducing pain during activity and improving core stability regarding functionality and endurance.

Is There a Sex Difference in Trunk Neuromuscular Control among Recreational Athletes during Cutting Maneuvers?

Trunk motion is most likely to influence knee joint injury risk, but little is known about sex-related differences in trunk neuromuscular control during changes of direction. The purpose of the present study was to test whether differences in trunk control between males and females during changes of direction exist. Twelve female and 12 male recreational athletes (with at least 10 years of experience in team sport) performed unanticipated changes of direction with 30° and 60° cut angles, while 3D trunk and leg kinematics, ground reaction forces and trunk muscles electromyography were recorded. Trunk kinematics at the time of peak knee abduction moment and directed co-contraction ratios for trunk muscles during the pre-activation and weight acceptance phases were determined. None of the trunk kinematics and co-contraction ratio variables, nor peak knee abduction moment differed between sexes. Compared to the 30° cut, trunk lateral flexion remained unchanged and trunk external rotation was reduced (p < 0.001; η²p (partial eta squared for effect size) = 0.78), while peak knee abduction moment was increased (p < 0.001; η²p = 0.84) at 60°. The sharper cutting angle induced muscle co-contraction during the pre-activation directed less towards trunk flexors (p < 0.01; η²p = 0.27) but more towards trunk medial flexors and rotators opposite to the movement direction (p < 0.001; η²p > 0.46). However, muscle co-contraction during the weight acceptance phase remained comparable between 30° and 60°. The lack of sex-related differences in trunk control does not explain knee joint injury risk discrepancies between sexes during changes of direction. Trunk neuromuscular strategies during sharper cutting angles revealed the importance of external oblique muscles to maintain trunk lateral flexion at the expense of trunk rotation. This provides new information for trunk strength training purposes for athletes performing changes of direction.

The content and effects of trunk rehabilitation on trunk and upper limb performance in people with multiple sclerosis: a systematic review.

Persons with multiple sclerosis (pwMS) could have an impaired trunk and reduced postural control, which negatively impacts activities of daily living. Evidence is growing to consider the positive effects of trunk training on fall incidence and balance problems. Effects on trunk and upper limb performance is unknown. This systematic review provides an overview of trunk training programs and their effects in MS, specifically focusing on the content of training modalities and the effects on trunk and upper limb performance. Two electronic databases were used: PubMed and Web Of Science (WOS). Intervention studies (with- and without control group) published in English, investigating the effects of active trunk training on trunk and upper limb performance in pwMS, were included. Sixteen studies met the criteria, investigating different rehabilitation modalities. The included interventions in the review varied between more generic postural interventions such as Pilates (N.=8) and Ai Chi (N.=1), with a focus on abdominal muscle activation, breathing, neutral position and lower extremity movements. Further, specifically developed trunk training programs like GroupCoreDIST/ SIT / CoDuSe (N.=6) and Bobath based trunk training (N.=1) are detected, with the main focus on trunk strengthening and dynamic movements. An overall improvement in trunk performance was reported in several tests on trunk strength, stability and coordination. While the majority of the programs integrated the upper limb, only half of them used upper limb outcome measures to evaluate the effect. Here, overall significant improvements were found for the upper limb. This systematic review showed that different types of trunk training programs can improve trunk and upper limb function in PwMS. The findings of this review suggest that a focus on trunk training to achieve effects on upper limb is reasonable. Future research is needed to further explore relations and the effect sizes.

Effectiveness of Swimming Program in Adolescents with Down Syndrome.

The aim of this study was to estimate the influence of a 33-week swimming program on aerobic capacity, muscle strength, balance, flexibility, and body composition of adolescents with Down syndrome (DS). Twenty-two adolescents diagnosed with DS were randomly allocated into the training group (T) and the control group (C). The T group participated in 33 weeks of water-based exercise and a swimming program while the control group maintained their normal daily activity. Following thirty-three weeks of swimming program, body mass, body fat, and BMI of the T group decreased significantly (from 56.8 ± 7.97 kg to 55.0 ± 7.11 kg, from 15.1 ± 4.47 kg to 13.2 ± 3.92 kg, and from 25.1 ± 2.37 to 24.0 ± 2.05, respectively) while a significant increase was recorded in C (from 57.3 ± 8.43 kg to 59.7 ± 8.29 kg, from 14.5 ± 2.76 kg to 16.0 ± 3.11 kg, and from 25.4 ± 2.46 to 26.0 ± 2.72, respectively). Moreover, significant improvement in aerobic capacity in the T group was noted; VO2max (mL/kg/min) increased by 16.3% in T and decreased by 4.8% in C. Improvement in static arm strength, trunk strength and endurance/functional strength were noted in T, while the parameters did not change in C. The speed of arm movement, balance and flexibility did not change following the intervention. Also, the aquatic skills improved significantly in the training group. Changes in C were not significant. The results of our study indicate that 33-week swimming program significantly improved health status and swimming skills in adolescents with DS.