scholarly journals Muscle Endurance Testing Using an Isokinetic Dynamometer and A Recumbent Stepper: A Correlation Study

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Pepin Marie-Eve ◽  
Thornton Alyssa ◽  
Gasperoni Vittoria ◽  
Kosky Jillian ◽  
Lowrey Laura ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Objective Measure ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Correlation Study ◽  
Muscle Endurance ◽  
Isokinetic Dynamometer ◽  
Average Force ◽  
Endurance Testing ◽  
Clinical Measures

Purpose: A lack of objective and validated clinical measures to assess Quadriceps muscle endurance (ME) currently exists. The Transitt model of the NuStep recumbent stepper has the capability to measure ME but has not been validated. Therefore, the aim of this study was to investigate the association between ME measures on the NuStep and the isokinetic dynamometer (ID). Methods: 30 healthy individuals were recruited to participate. On both the NuStep (70°/90° knee flexion) and ID (70° knee flexion), the participants were instructed to hold a submaximal isometric unilateral knee extension contraction until exhaustion. Descriptive statistics, inferential statistics and correlation analyses were used with significance set at p<0.05. Results: There was excellent correlation (r between 0.813 to 0.840, p<0.001) between the average force generated by the individuals on the ID and the NuStep. There was a fair correlation (r between 0.331 to 0.413, p<0.05) for the ME measures between the ID and the NuStep. Conclusions: The NuStep shows excellent agreement for average force measurements. Future studies are needed to validate the NuStep as an objective measure of ME in both healthy and clinical populations.

scholarly journals Handgrip and quadriceps muscle endurance testing in young adults

SpringerPlus ◽  
2013 ◽  
Vol 2 (1) ◽  
pp. 451 ◽  
Author(s):  
Ciara White ◽  
Kimberley Dixon ◽  
Dinesh Samuel ◽  
Maria Stokes
Keyword(s):  
Young Adults ◽  
Quadriceps Muscle ◽  
Muscle Endurance ◽  
Endurance Testing

scholarly journals Quadriceps Strength Symmetry Does Not Modify Gait Mechanics After Anterior Cruciate Ligament Reconstruction, Rehabilitation, and Return-to-Sport Training

2020 ◽  
pp. 036354652098007
Author(s):  
Elanna K. Arhos ◽  
Jacob J. Capin ◽  
Thomas S. Buchanan ◽  
Lynn Snyder-Mackler
Keyword(s):  
Knee Flexion ◽  
Cruciate Ligament ◽  
Return To Sport ◽  
Quadriceps Muscle ◽  
Quadriceps Strength ◽  
Flexion Angle ◽  
Knee Flexion Angle ◽  
Sport Training ◽  
Gait Biomechanics ◽  
Peak Knee

Background: After anterior cruciate ligament (ACL) reconstruction (ACLR), biomechanical asymmetries during gait are highly prevalent, persistent, and linked to posttraumatic knee osteoarthritis. Quadriceps strength is an important clinical measure associated with preoperative gait asymmetries and postoperative function and is a primary criterion for return-to-sport clearance. Evidence relating symmetry in quadriceps strength with gait biomechanics is limited to preoperative and early rehabilitation time points before return-to-sport training. Purpose/Hypothesis: The purpose was to determine the relationship between symmetry in isometric quadriceps strength and gait biomechanics after return-to-sport training in athletes after ACLR. We hypothesized that as quadriceps strength symmetry increases, athletes will demonstrate more symmetric knee joint biomechanics, including tibiofemoral joint loading during gait. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Of 79 athletes enrolled in the ACL-SPORTS Trial, 76 were participants in this study after completing postoperative rehabilitation and 10 return-to-sport training sessions (mean ± SD, 7.1 ± 2.0 months after ACLR). All participants completed biomechanical walking gait analysis and isometric quadriceps strength assessment using an electromechanical dynamometer. Quadriceps strength was calculated using a limb symmetry index (involved limb value / uninvolved limb value × 100). The biomechanical variables of interest included peak knee flexion angle, peak knee internal extension moment, sagittal plane knee excursion at weight acceptance and midstance, quadriceps muscle force at peak knee flexion angle, and peak medial compartment contact force. Spearman rank correlation (ρ) coefficients were used to determine the relationship between limb symmetry indexes in quadriceps strength and each biomechanical variable; alpha was set to .05. Results: Of the 76 participants, 27 (35%) demonstrated asymmetries in quadriceps strength, defined by quadriceps strength symmetry <90% (n = 23) or >110% (n = 4) (range, 56.9%-131.7%). For the biomechanical variables of interest, 67% demonstrated asymmetry in peak knee flexion angle; 68% and 83% in knee excursion during weight acceptance and midstance, respectively; 74% in internal peak knee extension moment; 57% in medial compartment contact force; and 74% in quadriceps muscle force. There were no significant correlations between quadriceps strength index and limb symmetry indexes for any biomechanical variable after return-to-sport training ( P > .129). Conclusion: Among those who completed return-to-sport training after ACLR, subsequent quadriceps strength symmetry was not correlated with the persistent asymmetries in gait biomechanics. After a threshold of quadriceps strength is reached, restoring strength alone may not ameliorate gait asymmetries, and current clinical interventions and return-to-sport training may not adequately target gait.

scholarly journals Kinesio Taping Does Not Alter Quadriceps Isokinetic Strength and Power in Healthy Nonathletic Men: A Prospective Crossover Study

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Paweł Korman ◽  
Anna Straburzyńska-Lupa ◽  
Radosław Rutkowski ◽  
Jakub Gruszczyński ◽  
Jacek Lewandowski ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Knee Extensors ◽  
Isokinetic Strength ◽  
Acute Effects ◽  
Isokinetic Dynamometer ◽  
Mean Power ◽  
Concentric Contractions ◽  
Kinesio Taping

Objectives. The effects of Kinesio Taping (KT) on muscular performance remain largely unclear. This study aimed to investigate the acute effects of KT on the maximum concentric and eccentric quadriceps isokinetic strength.Study Design. This is a single-blinded, placebo crossover, repeated measures study.Methods. Maximum isokinetic concentric/eccentric extension torque, work, and power were assessed by an isokinetic dynamometer without taping (NT) and with KT or placebo taping (PT) in 17 healthy young men. Repeated measures one-way analysis of variance (ANOVA) was used for statistical analyses.Results. Testing concentric contractions at 60°/s or 180°/s isokinetic speed, no significant differences in peak torque (Nm), total work (J), or mean power (W) were noted among the application modes under different conditions. Testing eccentric contractions at 30°/s or 60°/s isokinetic speed, no significant differences in mentioned parameters were noted, respectively. KT on the quadriceps neither decreased nor increased muscle strength in the participants.Conclusion. KT application onto the skin overlying the quadriceps muscle does not enhance the strength or power of knee extensors in healthy men.

Comparison of Biomechanical Factors between the Kicking and Stance Limbs

2004 ◽  
Vol 13 (2) ◽  
pp. 135-150 ◽  
Author(s):  
Scott Ross ◽  
Kevin Guskiewicz ◽  
William Prentice ◽  
Robert Schneider ◽  
Bing Yu
Keyword(s):  
Knee Flexion ◽  
Reaction Force ◽  
Knee Extension ◽  
Knee Kinematic ◽  
Vertical Ground Reaction Force ◽  
Time To Peak ◽  
Balance Task ◽  
Vertical Ground ◽  
Biomechanical Factors ◽  
Anterior Posterior

Objective:T o determine differences between contralateral limbs’ strength, proprio-ception, and kinetic and knee-kinematic variables during single-limb landing.Setting:Laboratory.Subjects:30.Measurements:Hip, knee, and foot isokinetic peak torques; anterior/posterior (AP) and medial/lateral (ML) sway displacements during a balance task; and stabilization times, vertical ground-reaction force (VGRF), time to peak VGRF, and knee-flexion range of motion (ROM) from initial foot contact to peak VGRF during single-limb landing.Results:The kicking limb had significantly greater values for knee-extension (P= .008) and -flexion (P= .047) peak torques, AP sway displacement (P= .010), knee-flexion ROM from initial foot contact to peak VGRF (P< .001), and time to peak VGRF (P= .004). No other dependent measures were significantly different between limbs (P> .05).Conclusion:The kicking limb had superior thigh strength, better proprioception, and greater knee-flexion ROM than the stance limb.

scholarly journals Midterm outcome and strength assessment after proximal rectus femoris refixation in athletes

2021 ◽  
Author(s):  
Maximilian Hinz ◽  
Stephanie Geyer ◽  
Felix Winden ◽  
Alexander Braunsperger ◽  
Florian Kreuzpointner ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Harris Hip Score ◽  
Postoperative Results ◽  
Postoperative Result ◽  
Strength Assessment ◽  
Competitive Athletes ◽  
Hip Flexion

Abstract Purpose Proximal rectus femoris avulsions (PRFA) are relatively rare injuries that occur predominantly among young soccer players. The aim of this study was to evaluate midterm postoperative results including strength potential via standardized strength measurements after proximal rectus femoris tendon refixation. It was hypothesized that the majority of competitive athletes return to competition (RTC) after refixation of the rectus femoris tendon without significant strength or functional deficits compared to the contralateral side. Methods Patients with an acute (< 6 weeks) PRFA who underwent surgical refixation between 2012 and 2019 with a minimum follow-up of 12 months were evaluated. The outcome measures compiled were the median Tegner Activity Scale (TAS) and mean RTC time frames, Harris Hip Score (HHS), Hip and Groin Outcome Score (HAGOS) subscales, International Hip Outcome Tool-33 (iHOT-33), and Visual Analog Scale (VAS) for pain. In addition, a standardized isometric strength assessment of knee flexion, knee extension, and hip flexion was performed to evaluate the functional result of the injured limb in comparison to the uninjured side. Results Out of 20 patients, 16 (80%) patients were available for final assessment at a mean follow-up of 44.8 ± SD 28.9 months. All patients were male with 87.5% sustaining injuries while playing soccer. The average time interval between trauma and surgery was 18.4 ± 8.5 days. RTC was possible for 14 out of 15 previously competitive athletes (93.3%) at a mean 10.5 ± 3.4 months after trauma. Patients achieved a high level of activity postoperatively with a median (interquartile range) TAS of 9 (7–9) and reported good to excellent outcome scores (HHS: 100 (96–100); HAGOS: symptoms 94.6 (89.3–100), pain 97.5 (92.5–100), function in daily living 100 (95–100), function in sport and recreation 98.4 (87.5–100), participation in physical activities 100 (87.5–100), quality of life 83.1 ± 15.6; iHot-33: 95.1 (81.6–99.8)). No postoperative complications were reported. Range of motion, isometric knee flexion and extension, as well as hip flexion strength levels were not statistically different between the affected and contralateral legs. The majority of patients were “very satisfied” (56.3%) or “satisfied” (37.5%) with the postoperative result and reported little pain (VAS 0 (0–0.5)). Conclusion Surgical treatment of acute PRFA yields excellent postoperative results in a young and highly active cohort. Hip flexion and knee extension strength was restored fully without major surgical complications. Level of evidence Retrospective cohort study; III.

scholarly journals Validation of a score tool for measurement of histological severity in juvenile dermatomyositis and association with clinical severity of disease

2013 ◽  
Vol 74 (1) ◽  
pp. 204-210 ◽  
Author(s):  
Hemlata Varsani ◽  
Susan C Charman ◽  
Charles K Li ◽  
Suely K N Marie ◽  
Anthony A Amato ◽  
...  
Keyword(s):  
Disease Activity ◽  
Muscle Biopsy ◽  
Juvenile Dermatomyositis ◽  
Intraclass Correlation ◽  
Latin Square ◽  
Quadriceps Muscle ◽  
Clinical Severity ◽  
Intraobserver Agreement ◽  
Biopsy Tissue ◽  
Clinical Measures

ObjectivesTo study muscle biopsy tissue from patients with juvenile dermatomyositis (JDM) in order to test the reliability of a score tool designed to quantify the severity of histological abnormalities when applied to biceps humeri in addition to quadriceps femoris. Additionally, to evaluate whether elements of the tool correlate with clinical measures of disease severity.Methods55 patients with JDM with muscle biopsy tissue and clinical data available were included. Biopsy samples (33 quadriceps, 22 biceps) were prepared and stained using standardised protocols. A Latin square design was used by the International Juvenile Dermatomyositis Biopsy Consensus Group to score cases using our previously published score tool. Reliability was assessed by intraclass correlation coefficient (ICC) and scorer agreement (α) by assessing variation in scorers’ ratings. Scores from the most reliable tool items correlated with clinical measures of disease activity at the time of biopsy.ResultsInter- and intraobserver agreement was good or high for many tool items, including overall assessment of severity using a Visual Analogue Scale. The tool functioned equally well on biceps and quadriceps samples. A modified tool using the most reliable score items showed good correlation with measures of disease activity.ConclusionsThe JDM biopsy score tool has high inter- and intraobserver agreement and can be used on both biceps and quadriceps muscle tissue. Importantly, the modified tool correlates well with clinical measures of disease activity. We propose that standardised assessment of muscle biopsy tissue should be considered in diagnostic investigation and clinical trials in JDM.

Muscle metabolic responses to exercise above and below the “critical power” assessed using 31P-MRS

2008 ◽  
Vol 294 (2) ◽  
pp. R585-R593 ◽  
Author(s):  
Andrew M. Jones ◽  
Daryl P. Wilkerson ◽  
Fred DiMenna ◽  
Jonathan Fulford ◽  
David C. Poole
Keyword(s):  
Critical Power ◽  
Quadriceps Muscle ◽  
High Energy ◽  
Knee Extension ◽  
Work Rate ◽  
Metabolic Responses ◽  
Time To Exhaustion ◽  
Resonance Spectroscopy ◽  
High Energy Phosphates ◽  
Constant Work Rate

We tested the hypothesis that the asymptote of the hyperbolic relationship between work rate and time to exhaustion during muscular exercise, the “critical power” (CP), represents the highest constant work rate that can be sustained without a progressive loss of homeostasis [as assessed using 31P magnetic resonance spectroscopy (MRS) measurements of muscle metabolites]. Six healthy male subjects initially completed single-leg knee-extension exercise at three to four different constant work rates to the limit of tolerance (range 3–18 min) for estimation of the CP (mean ± SD, 20 ± 2 W). Subsequently, the subjects exercised at work rates 10% below CP (<CP) for 20 min and 10% above CP (>CP) for as long as possible, while the metabolic responses in the contracting quadriceps muscle, i.e., phosphorylcreatine concentration ([PCr]), Pi concentration ([Pi]), and pH, were estimated using 31P-MRS. All subjects completed 20 min of <CP exercise without duress, whereas the limit of tolerance during >CP exercise was 14.7 ± 7.1 min. During <CP exercise, stable values for [PCr], [Pi], and pH were attained within 3 min after the onset of exercise, and there were no further significant changes in these variables (end-exercise values = 68 ± 11% of baseline [PCr], 314 ± 216% of baseline [Pi], and pH 7.01 ± 0.03). During >CP exercise, however, [PCr] continued to fall to the point of exhaustion and [Pi] and pH changed precipitously to values that are typically observed at the termination of high-intensity exhaustive exercise (end-exercise values = 26 ± 16% of baseline [PCr], 564 ± 167% of baseline [Pi], and pH 6.87 ± 0.10, all P < 0.05 vs. <CP exercise). These data support the hypothesis that the CP represents the highest constant work rate that can be sustained without a progressive depletion of muscle high-energy phosphates and a rapid accumulation of metabolites (i.e., H+ concentration and [Pi]), which have been associated with the fatigue process.

scholarly journals Contralateral Muscle Imbalances and Physiological Profile of Recreational Aerial Athletes

2019 ◽  
Vol 4 (3) ◽  
pp. 49
Author(s):  
Ruggieri ◽  
Costa
Keyword(s):  
Cardiorespiratory Fitness ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Cardiovascular Fitness ◽  
Dominant Hand ◽  
Lower Body ◽  
Physiological Profile ◽  
Significant Difference ◽  
H:Q Ratio ◽  
Contralateral Muscle

Background: Aerial fitness is quickly gaining popularity; however, little is known regarding the physiological demands of aerial athletes. The purpose of the study was to examine contralateral muscle imbalances, compare dominant versus non-dominant hamstrings-to-quadriceps (H:Q) ratios, and to establish a physiological profile of recreational aerial athletes. Methods: Thirteen aerialist women visited a local aerial studio to participate in a data collection session to examine isometric levels of upper and lower body strength, muscle endurance, flexibility, balance, and cardiovascular fitness. Results: No significant differences were found between dominant and non-dominant hand grip strength (p = 0.077), dominant and non-dominant isometric knee flexion (p = 0.483), dominant and non-dominant isometric knee extension (p = 0.152), or dominant and non-dominant isometric H:Q ratios (p = 0.102). In addition, no significant difference was found between isometric dominant H:Q ratio and the widely-used value of 0.60 (p = 0.139). However, isometric non-dominant H:Q ratio was significantly lower than the 0.60 criterion (p = 0.004). Aerial athletes demonstrated to have excellent flexibility, balance, cardiorespiratory fitness, and average strength. Conclusions: Aerial fitness may be another recreational activity that could be used to maintain higher levels of flexibility, balance, cardiorespiratory fitness, and strength. Aerialists may want to consider focusing on strengthening the lower body and balancing the hamstrings and quadriceps muscle strength.

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