Profiling Isokinetic Strength by Leg Preference and Position in Rugby Union Athletes

2016 ◽  
Vol 11 (4) ◽  
pp. 500-507 ◽  
Author(s):  
Scott R. Brown ◽  
Matt Brughelli ◽  
Lee A. Bridgeman
Keyword(s):  
Lower Extremity ◽  
Peak Torque ◽  
Knee Extension ◽  
Rugby Union ◽  
Lower Extremity Injury ◽  
Cross Sectional ◽  
Hip Strength ◽  
Lower Extremity Muscle ◽  
Lower Extremity Strength ◽  
Sectional Analysis

Context:Muscle imbalances aid in the identification of athletes at risk for lower-extremity injury. Little is known regarding the influence that leg preference or playing position may have on lower-extremity muscle strength and asymmetry.Purpose:To investigate lower-extremity strength profiles in rugby union athletes and compare isokinetic knee- and hip-strength variables between legs and positions.Methods:Thirty male academy rugby union athletes, separated into forwards (n = 15) and backs (n = 15), participated in this cross-sectional analysis. Isokinetic dynamometry was used to evaluate peak torque, angle of peak torque, and strength ratios of the preferred and nonpreferred legs during seated knee extension/flexion and supine hip extension/flexion at 60°/s.Results:Backs were older (ES = 1.6) but smaller in stature (ES = –0.47) and body mass (ES = –1.3) than the forwards. The nonpreferred leg was weaker than the preferred leg for forwards during extension (ES = –0.37) and flexion (ES = –0.21) actions and for backs during extension (ES = –0.28) actions. Backs were weaker at the knee than forwards in the preferred leg during extension (ES = –0.50) and flexion (ES = –0.66) actions. No differences were observed in strength ratios between legs or positions. Backs produced peak torque at longer muscle lengths in both legs at the knee (ES = –0.93 to –0.94) and hip (ES = –0.84 to –1.17) than the forwards.Conclusions:In this sample of male academy rugby union athletes, the preferred leg and forwards displayed superior strength compared with the nonpreferred leg and backs. These findings highlight the importance of individualized athletic assessments to detect crucial strength differences in male rugby union athletes.

Lower-Extremity Isokinetic Strength Profiling in Professional Rugby League and Rugby Union

2014 ◽  
Vol 9 (2) ◽  
pp. 358-361 ◽  
Author(s):  
Scott R. Brown ◽  
Matt Brughelli ◽  
Peter C. Griffiths ◽  
John B. Cronin
Keyword(s):  
Lower Extremity ◽  
Knee Flexion ◽  
Peak Torque ◽  
Rugby League ◽  
Knee Extension ◽  
Rugby Union ◽  
Joint Torque ◽  
Cross Sectional ◽  
Hip Strength ◽  
Hip Extension

Purpose:While several studies have documented isokinetic knee strength in junior and senior rugby league players, investigations of isokinetic knee and hip strength in professional rugby union players are limited. The purpose of this study was to provide lower-extremity strength profiles and compare isokinetic knee and hip strength of professional rugby league and rugby union players.Participants:32 professional rugby league and 25 professional rugby union players.Methods:Cross-sectional analysis. Isokinetic dynamometry was used to evaluate peak torque and strength ratios of the dominant and nondominant legs during seated knee-extension/flexion and supine hip-extension/flexion actions at 60°/s.Results:Forwards from both codes were taller and heavier and had a higher body-mass index than the backs of each code. Rugby union forwards produced significantly (P < .05) greater peak torque during knee flexion in the dominant and nondominant legs (ES = 1.81 and 2.02) compared with rugby league forwards. Rugby league backs produced significantly greater hip-extension peak torque in the dominant and nondominant legs (ES = 0.83 and 0.77) compared with rugby union backs. There were no significant differences in hamstring-to-quadriceps ratios between code, position, or leg. Rugby union forwards and backs produced significantly greater knee-flexion-to-hip-extension ratios in the dominant and nondominant legs (ES = 1.49–2.26) than rugby union players.Conclusions:It seems that the joint torque profiles of players from rugby league and union codes differ, which may be attributed to the different demands of each code.

The Relationship between Lower Extremity Isokinetic Work and Single-Leg Functional Hop-Work Test

2006 ◽  
Vol 15 (2) ◽  
pp. 95-104 ◽  
Author(s):  
Robert English ◽  
Mary Brannock ◽  
Wan Ting Chik ◽  
Laura S. Eastwood ◽  
Tim Uhl
Keyword(s):  
Body Weight ◽  
Lower Extremity ◽  
Outcome Measures ◽  
Study Design ◽  
Peak Torque ◽  
Knee Extension ◽  
Isokinetic Strength ◽  
Total Work ◽  
Lower Extremity Strength ◽  
The Relationship

Context:Lower extremity functional testing assesses strength, power, and neuro-muscular control. There are only moderate correlations between distance hopped and isokinetic strength measures.Objective:Determine if incorporating body weight in the single-leg hop for distance increases the correlation to isokinetic measures.Study Design:Correlational study.Setting:Musculoskeletal laboratory.Participants:30 healthy college students; 15 men and 15 women; ages 18 to 30 years.Main Outcome Measures:Isokinetic average peak torque and total work of quadriceps and hamstrings and single-leg hop work and distance.Results:Significant correlations include hop work to total-work knee extension (r= .89), average peak-torque knee extension (r= .88), distance hopped to total-work knee extension (r= .56) and average peak-torque knee extension (r= .63). Correlations involving hop work were greater than distance hopped (P< .05).Conclusions:Use of body weight in the assessment of distance hopped provides better information about the patient’s lower extremity strength and ability than the distance hopped alone.

scholarly journals MUSCLE QUALITY, STRENGTH, AND LOWER EXTREMITY PHYSICAL PERFORMANCE IN THE BALTIMORE LONGITUDINAL STUDY OF AGING

2017 ◽  
pp. 1-5
Author(s):  
N. Chiles Shaffer ◽  
E. Fabbri ◽  
L. Ferrucci ◽  
M. Shardell ◽  
E.M. Simonsick ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Lower Extremity ◽  
Concurrent Validity ◽  
Knee Extension ◽  
Muscle Quality ◽  
Cross Sectional ◽  
Age Related ◽  
Alternative Measures ◽  
Baltimore Longitudinal Study ◽  
Sectional Analysis

Background: Muscle quality is defined as the force generated by each volumetric unit of muscle tissue. No consensus exists on an optimal measure of muscle quality, impeding comparison across studies and implementation in clinical settings. It is unknown whether muscle quality measures that rely on complex and expensive tests, such as isokinetic dynamometry and computerized tomography correlate with lower extremity performance (LEP) any better than measures derived from simpler and less expensive tests, such as grip strength (Grip) and appendicular lean mass (ALM) assessed by DXA. Additionally, whether muscle quality is more strongly associated with LEP than strength has not been fully tested. Objectives: This study compares the concurrent validity of alternative measures of muscle quality and characterizes their relationship with LEP. We also whether muscle quality correlates more strongly with LEP than strength alone. Design: Cross-sectional analysis. Setting: Community. Participants: 365 men and 345 women 65 years of age and older in the Baltimore Longitudinal Study of Aging. Measures: Thigh cross-sectional area (TCSA), isokinetic and isometric knee extension strength (ID), BMI adjusted ALM (ALMBMI) from DXA, and Grip. Concurrent validity was assessed as the percent variance of different measures of LEP explained by each muscle quality measure. In addition, we compared LEP relationships between each measure of strength and its correspondent value of muscle quality. Confidence intervals for differences in percent variance were calculated by bootstrapping. Results: Grip/ALMBMI explained as much variance as ID/TCSA across all LEP measures in women and most in men. Across all LEP measures, strength explained as much variance of LEP as muscle quality. Conclusions: Grip/ALMBMI and ID/TCSA measures had similar correlations with LEP. Muscle quality did not outperform strength. Although evaluating muscle quality may be useful to assess age-related mechanisms of change in muscle strength, measures of strength alone may suffice to understand the relationship between muscle and LEP.

scholarly journals Preoperative prevalence of deep vein thrombosis in patients scheduled to have surgery for degenerative musculoskeletal disorders

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Keigo Sato ◽  
Hideki Date ◽  
Takehiro Michikawa ◽  
Mitsuhiro Morita ◽  
Kazue Hayakawa ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Musculoskeletal Disorders ◽  
Pulmonary Thromboembolism ◽  
Elective Surgery ◽  
Knee Surgery ◽  
Care Providers ◽  
Cross Sectional ◽  
Cross Sectional Analysis ◽  
Sectional Analysis ◽  
D Dimer

Abstract Background Although the incidence of symptomatic pulmonary thromboembolism after elective surgery for degenerative musculoskeletal disorders is comparatively low, it is extremely detrimental to both patients and health-care providers. Therefore, its prevention is mandatory. We aimed to perform a cross-sectional analysis of deep venous thrombosis (DVT) before elective surgery for degenerative musculoskeletal disorders, including total knee arthroplasty (TKA), total hip arthroplasty (THA), and spinal surgery, and identify the factors associated with the incidence of preoperative DVT. Methods The clinical data of patients aged ≥ 30 years who underwent TKA or THA, and spine surgery for lumbar or cervical degenerative disorders at our institution were retrospectively collected. D-dimer levels were measured preoperatively in all the patients scheduled for surgery. For the patients with D-dimer levels ≥ 1 µg/mL or who were determined by their physicians to be at high risk of DVT, the lower extremity vein was preoperatively examined for DVT on ultrasonography. Results Overall, we retrospectively evaluated 1236 consecutive patients, including 701 men and 535 women. Of the patients, 431 and 805 had D-dimer levels ≥ 1 and < 1 µg/mL, respectively. Of 683 patients who underwent lower extremity ultrasonography, 92 had proximal (n = 7) and distal types (n = 85) of DVT. The preoperative prevalence of DVT was 7.4 %. No patient had the incidence of postoperative symptomatic venous thromboembolism. A multivariate analysis revealed that age ≥ 80 years (odds ratio [OR], 95 % confidence interval [CI]: 2.8, 1.1–7.3), knee surgery (2.1, 1.1–4.0), American Society of Anesthesiologists (ASA) grade 2 (2.8, 1.2–6.8), ASA grades 3 or 4 (3.1, 1.0–9.4), and malignancy (1.9, 1.1–3.2) were significantly associated with DVT incidence. Conclusions This is the first study to conduct a cross-sectional analysis of preoperative DVT data of patients scheduled for elective surgery for degenerative musculoskeletal disorders. Although whether screening for preoperative DVT is needed to prevent postoperative symptomatic pulmonary thromboembolism remains to be clarified, our data suggested that DVT should be noted before surgery in the patients with advanced age, knee surgery, high ASA physical status, and malignancy.

scholarly journals Tai Chi training’s effect on lower extremity muscle co-contraction during single- and dual-task gait: Cross-sectional and randomized trial studies

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0242963
Author(s):  
Peter M. Wayne ◽  
Brian J. Gow ◽  
Fengzhen Hou ◽  
Yan Ma ◽  
Jeffrey M. Hausdorff ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Postural Control ◽  
Usual Care ◽  
Randomized Trial ◽  
Dual Task ◽  
Muscle Activation ◽  
Tai Chi ◽  
Mean Difference ◽  
Cross Sectional ◽  
Lower Extremity Muscle

Background Tai Chi (TC) mind-body exercise has been shown to reduce falls and improve balance and gait, however, few studies have evaluated the role of lower extremity muscle activation patterns in the observed benefits of TC on mobility. Purpose To perform an exploratory analysis of the association between TC training and levels of lower extremity muscle co-contraction in healthy adults during walking under single-task (ST) and cognitive dual-task (DT) conditions. Methods Surface electromyography of the anterior tibialis and lateral gastrocnemius muscles was recorded during 90 sec trials of overground ST (walking normally) and DT (walking with verbalized serial subtractions) walking. A mean co-contraction index (CCI), across all strides, was calculated based on the percentage of total muscle activity when antagonist muscles were simultaneously activated. A hybrid study design investigated long-term effects of TC via a cross-sectional comparison of 27 TC experts and 60 age-matched TC-naïve older adults. A longitudinal comparison assessed the shorter-term effects of TC; TC-naïve participants were randomly allocated to either 6 months of TC training or to usual care. Results Across all participants at baseline, greater CCI was correlated with slower gait speed under DT (β(95% CI) = -26.1(-48.6, -3.7)) but not ST (β(95% CI) = -15.4(-38.2, 7.4)) walking. Linear models adjusting for age, gender, BMI and other factors that differed at baseline indicated that TC experts exhibited lower CCI compared to TC naives under DT, but not ST conditions (ST: mean difference (95% CI) = -7.1(-15.2, 0.97); DT: mean difference (95% CI) = -10.1(-18.1, -2.4)). No differences were observed in CCI for TC-naive adults randomly assigned to 6 months of TC vs. usual care. Conclusion Lower extremity muscle co-contraction may play a role in the observed benefit of longer-term TC training on gait and postural control. Longer-duration and adequately powered randomized trials are needed to evaluate the effect of TC on neuromuscular coordination and its impact on postural control. Trial registration The randomized trial component of this study was registered at ClinicalTrials.gov (NCT01340365).

Landing Kinematics and Isometric Hip Strength of Individuals With Chronic Ankle Instability

2019 ◽  
Vol 40 (8) ◽  
pp. 969-977 ◽  
Author(s):  
Ryan S. McCann ◽  
Masafumi Terada ◽  
Kyle B. Kosik ◽  
Phillip A. Gribble
Keyword(s):  
Lower Extremity ◽  
Ankle Instability ◽  
External Rotation ◽  
Peak Torque ◽  
Chronic Ankle Instability ◽  
Initial Contact ◽  
Level Of Evidence ◽  
Hip Strength ◽  
Hip Kinematics ◽  
Rotation Strength

Background: Chronic ankle instability (CAI) is associated with hip strength deficits and altered movement in the lower extremity. However, it remains unclear how hip strength deficits contribute to lateral ankle sprain (LAS) mechanisms. We aimed to compare lower extremity landing kinematics and isometric hip strength between individuals with and without CAI and examine associations between hip kinematics and strength. Methods: Seventy-six individuals completed 5 single-leg landings, during which we collected three-dimensional ankle, knee, and hip kinematics from 200 milliseconds pre–initial contact to 50 milliseconds post–initial contact. We calculated average peak torque (Nm/kg) from 3 trials of isometric hip extension, abduction, and external rotation strength testing. One-way analyses of variance assessed group differences (CAI, LAS coper, and control) in hip strength and kinematics. Pearson product moment correlations assessed associations between hip kinematics and strength. We adjusted the kinematic group comparisons and correlation analyses for multiple comparisons using the Benjamini-Hochberg method. Results: The CAI group exhibited less hip abduction during landing than LAS copers and controls. The CAI group had lower hip external rotation strength than LAS copers ( P = .04, d = 0.62 [0.05, 1.17]) and controls ( P < .01, d = 0.87 [0.28, 1.43]). Effect sizes suggest that the CAI group had deficits in EXT compared with controls ( d = 0.63 [0.06, 1.19]). Hip strength was not associated with hip landing kinematics for any group. Conclusion: Altered landing mechanics displayed by the CAI group may promote mechanisms of LAS, but they are not associated with isometric hip strength. However, hip strength deficits may negatively impact other functional tasks, and they should still be considered during rehabilitation. Level of Evidence: Level III, case-control study.

scholarly journals Females have a Higher Post-Concussion Subsequent Injury Rate than Male Collegiate Athletes

Neurology ◽  
2019 ◽  
Vol 93 (14 Supplement 1) ◽  
pp. S28.1-S28
Author(s):  
Thomas Buckely ◽  
Jessie Oldham
Keyword(s):  
Lower Extremity ◽  
Student Athletes ◽  
Knee Injuries ◽  
Injury Rate ◽  
Collegiate Athletes ◽  
Elevated Risk ◽  
Lower Extremity Injury ◽  
Ankle Sprains ◽  
Lateral Ankle ◽  
Lower Extremity Muscle

ObjectiveThe purpose of this study is to compare post-concussion lower extremity musculoskeletal (MSK) injury between sexes.BackgroundEmerging evidence suggests that there is an elevated risk of lower extremity MSK injury in the year following concussion. Indeed, we have previously reported a 1.6 –2.9 times elevated risk of lower extremity injury across a diverse population of collegiate student athletes at the conclusion of their athletic careers. However, there are recent and important calls to investigate the role of gender in concussion research and collegiate female student-athletes have elevated risks of specific injuries.Design/MethodsWe recruited 335 student-athletes (62.1% female, mean age, 21.2 ± 1.4 years old) across 13 sports from 17 NCAA member institutions. Participants self-reported concussions under three categories: 1) selfreported concussions, 2) acknowledged unreported concussions (e.g., “hidden”), 3) unrecognized concussions (e.g., memory loss following a head impact). The lower extremity MSK injuries were self-reported 1) lateral ankle sprains, 2) knee sprains, or 3) lower extremity muscle strain. Chi-square analyses identified the association between each of the concussion variables and lower extremity MSK between self-reported sexes.ResultsFor females, there was a significant association between 1) reported concussions and knee injuries (p = 0.018, OR = 2.22, 95% CI: 1.18 – 4.21), 2) unreported concussions and knee injuries (p = 0.005, OR = 3.73, 95% CI: 1.51 – 9.22), 3) unrecognized concussions and lateral ankle sprains (p = 0.007, OR = 2.61, 95% CI: 1.32 – 5.15). For males, there was only a significant association between unrecognized concussions and muscle strains (p = 0.020, odds ratio = 2.39, 95% CI: 1.16 – 4.92).ConclusionsThe results of this study suggest females are at higher risk of post-concussion subsequent MSK injury over the course of their collegiate athletic career. Consistent with recent concussion related findings, these results may highlight a gender difference in concussion response and suggests future studies continue to differentiate gender during analysis.

Linkage of myostatin pathway genes with knee strength in humans

2004 ◽  
Vol 17 (3) ◽  
pp. 264-270 ◽  
Author(s):  
W. Huygens ◽  
M. A. Thomis ◽  
M. W. Peeters ◽  
J. Aerssens ◽  
R. Janssen ◽  
...  
Keyword(s):  
Linkage Analysis ◽  
Muscle Mass ◽  
Single Point ◽  
Young Male ◽  
Peak Torque ◽  
Knee Extension ◽  
Candidate Gene Approach ◽  
Potential Candidate ◽  
Cross Sectional ◽  
Knee Strength

This study was the first to explore the potential role of the myostatin ( GDF8) pathway in relation to muscle strength and estimated muscle cross-sectional area in humans using linkage analysis with a candidate gene approach. In young male sibs ( n = 329) 11 polymorphic markers in or near 10 candidate genes from the myostatin pathway were genotyped. Muscle mass was estimated by anthropometric measurements, and maximal knee strength was evaluated using isokinetic dynamometers (Cybex NORM). Single-point nonparametric variance components and linear quantitative trait locus regression linkage analysis methods were used. Linkage patterns were observed between knee extension and flexion peak torque with markers D2S118 ( GDF8), D6S1051 ( CDKN1A), and D11S4138 ( MYOD1), and a maximum LOD score of 2.63 ( P = 0.0002) was observed with D2S118. The ratios of peak torque over muscle and bone area of the midthigh of the lower contraction velocity (60°/s) showed more frequently significant LOD scores than the torques at high velocity (240°/s). Although myostatin is physiologically more related to muscle mass through possible effects of hyperplasia and hypertrophy than it is to strength, only two estimated muscle cross-sectional areas were marginally linked (LOD 1.06 and 1.07, P = 0.01) with marker D2S118 near GDF8 (2q32.2). The present results gave suggestive evidence that the myostatin pathway might be important for strength phenotypes, and GDF8, CDKN1A, and MYOD1 are potential candidate regions for a further and denser mapping with respect to these phenotypes.

scholarly journals Home-Based Multidisciplinary Rehabilitation following Hip Fracture Surgery: What Is the Evidence?

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Kathleen Donohue ◽  
Richelle Hoevenaars ◽  
Jocelyn McEachern ◽  
Erica Zeman ◽  
Saurabh Mehta
Keyword(s):  
Hip Fracture ◽  
Lower Extremity ◽  
Functional Status ◽  
Systematic Review Methodology ◽  
Balance Confidence ◽  
Hip Fracture Surgery ◽  
Lower Extremity Muscle ◽  
Home Based ◽  
Lower Extremity Strength ◽  
Fracture Surgery

Objective. To determine the effects of multidisciplinary home rehabilitation (MHR) on functional and quality of life (QOL) outcomes following hip fracture surgery.Methods. Systematic review methodology suggested by Cochrane Collboration was adopted. Reviewers independently searched the literature, selected the studies, extracted data, and performed critical appraisal of studies. Summary of the results of included studies was provided.Results. Five studies were included. Over the short-term, functional status and lower extremity strength were better in the MHR group compared to the no treatment group (NT). Over the long-term, the MHR group showed greater improvements in balance confidence, functional status, and lower extremity muscle strength compared to NT group, whereas the effect on QOL and mobility was inconsistent across the studies. Several methodological issues related to study design were noted across the studies.Conclusion. The MHR was found to be more effective compared to the NT in improving functional status and lower extremity strength in patients with hip fracture surgery. Results of this review do not make a strong case for MHR due to high risk of bias in the included studies. Further research is required to accurately characterize the types of disciplines involved in MHR and frequency and dosage of intervention.

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