Endurance time is joint-specific: A modelling and meta-analysis investigation

Law, Laura Frey; Avin, Keith G.

doi:10.1080/00140130903389068

Cited by 112 publications

(92 citation statements)

References 194 publications

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“…More recently, comparisons between several of these models observed that equations varied by joint region (El Ahrache et al, 2006; Ma et al, 2009; Ma et al, 2011). Likewise, a large meta-analysis of 194 publications involving experimental fatigue data confirmed joint-specific intensity-ET relationships (Frey Law and Avin, 2010). Thus, ETs vary as a function of task intensity, but also based on the joint region involved.…”

Section: Introductionmentioning

confidence: 81%

A three-compartment muscle fatigue model accurately predicts joint-specific maximum endurance times for sustained isometric tasks

Law

Looft

Heitsman

2012

Journal of Biomechanics

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The development of localized muscle fatigue has classically been described by the nonlinear intensity – endurance time (ET) curve (Rohmert, 1960; El Ahrache et al., 2006). These empirical intensity-ET relationships have been well-documented and vary between joint regions. We previously proposed a three-compartment biophysical fatigue model, consisting of compartments (i.e. states) for active (MA), fatigued (MF), and resting (MR) muscle, to predict the decay and recovery of muscle force (Xia and Frey Law, 2008). The purpose of this investigation was to determine optimal model parameter values, fatigue (F) and recovery (R), which define the “flow rate” between muscle states and to evaluate the model’s accuracy for estimating expected intensity – ET curves. Using a grid-search approach with modified Monte Carlo simulations, over 1 million F and R permutations were used to predict the maximum ET for sustained isometric tasks at 9 intensities ranging from 10 – 90% of maximum in 10% increments (over 9 million simulations total). Optimal F and R values ranged from 0.00589 (Fankle) and 0.0182 (Rankle) to 0.00058 (Fshoulder) and 0.00168 (Rshoulder), reproducing the intensity-ET curves with low mean RMS errors: shoulder (2.7s), hand/grip (5.6s), knee (6.7s), trunk (9.3s), elbow (9.9s), and ankle (11.2s). Testing the model at different task intensities (15 – 95% maximum in 10% increments) produced slightly higher errors, but largely within the 95% prediction intervals expected for the intensity-ET curves. We conclude that this three-compartment fatigue model can be used to accurately represent joint-specific intensity-ET curves, which may be useful for ergonomic analyses and/or digital human modeling applications.

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Section: Introductionmentioning

confidence: 81%

A three-compartment muscle fatigue model accurately predicts joint-specific maximum endurance times for sustained isometric tasks

Law

Looft

Heitsman

2012

Journal of Biomechanics

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“…A comparison of the relationship between relative exertion level and endurance showed that the data reasonably followed the traditional form of a decreasing power function for both the obese and non-obese groups. (38,39) Previous work (18) on shoulder flexion endurance during sustained isometric tasks-which involved participants of similar age, stature, and BMI as here-indicated that the non-obese group had ∼20% longer endurance than the obese group.…”

Section: Effect Of Obesity On Functional Performancementioning

confidence: 90%

The Influences of Obesity and Age on Functional Performance During Intermittent Upper Extremity Tasks

Cavuoto

Nussbaum

2014

Journal of Occupational and Environmental Hygiene

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In this study, the main and interactive effects of obesity and age on functional performance were assessed during intermittent exertions involving the upper extremity. The prevalence of obesity has doubled over the past 30 years and this increase is associated with higher health care costs, rates of workplace injury, and lost workdays. Obesity and aging can modify job demands and affect worker capacity in terms of muscular and psychomotor function. However, there is a lack of empirical studies quantifying the work-relevant (or ergonomic) impacts related to task demands, capacities, and their potential imbalance. Eight obese and eight non-obese participants from each of two age groups (18-25 and 50-65 years) completed three endurance tasks involving fixed levels of task demands: hand grip, shoulder flexion, and a simulated assembly task using the upper extremity. Measures of functional performance including endurance, discomfort, motor control, and task performance were recorded for each of the task conditions. Endurance times were ∼60% longer for the non-obese group, and older participants had longer endurance times; however there was no evidence of interactive effects of obesity and age. Obesity also impaired functional performance, as indicated by higher rates of strength loss, increases in discomfort, and declines in task performance. These observed impairments may reflect underlying physiological differences among individuals who are obese, but that are independent of age. Obesity-related impairments may have implications for the design of work duration and demand level to prevent fatigue development for workers who are obese.

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“…interpolated twitch techniques, then their relative-intensity target workload will be less than expected. A recent meta-analysis modeled endurance times as a function of task intensity for sustained isometric contractions at several joints (7). Using these models, the current 30 sec difference in endurance time observed between men and women at the elbow would require a difference in central activation of 14-16% between the sexes (e.g.…”

Section: Discussionmentioning

confidence: 99%

Sex Differences in Fatigue Resistance Are Muscle Group Dependent

Avin

Naughton

Ford

et al. 2010

Medicine &Amp; Science in Sports &Amp; Exercise

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Purpose-Females are often reported to be generally more resistant to fatigue than males for relative intensity tasks. This has been observed repeatedly for elbow flexors, whereas at the ankle sex differences appear less robust, suggesting localized rather than systemic influences. Thus, the purpose of this study was to examine sex differences in fatigue resistance at muscle groups in a single cohort and which factors, if any, predict endurance time.Methods-Thirty-two (16 female) young adults (19 to 44 yrs) performed sustained isometric contractions at 50% maximum voluntary isometric contraction to failure for elbow flexion and ankle dorsiflexion. Pain, exertion, and muscle electromyography (EMG) were assessed throughout. Selfreported baseline activity was measured using the International Physical Activity Questionnaire.Results-Females (112.3 ± 6.2 sec) were significantly more resistant to fatigue than males (80.3 ± 5.8 sec) at the elbow (p=0.001); but not at the ankle (p=0.45; 140.6 ± 10.7 vs. 129.2 ± 10.5 sec). Peak torque was greater in males than females (p < 0.0001) at the ankle (45.0 ± 1.7 vs. 30.1 ± 1.0 Nm) and the elbow (75.7 ± 3.1 vs. 34.4 ± 2.2 Nm). Peak torque was significantly related to endurance time at the elbow (R 2 = 0.30), but not at the ankle (R 2 = 0.03). Peak pain, rate of pain increase, peak exertion, EMG, and baseline physical activity did not differ between sexes.Conclusion-Sex differences in fatigue resistance are muscle group specific. Women were more fatigue-resistant at the elbow but not the ankle during a sustained isometric contraction. Further, factors which may contribute to fatigue-resistance for one muscle group (e.g. sex, peak torque) may not be critical at another.

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Endurance time is joint-specific: A modelling and meta-analysis investigation

Cited by 112 publications

References 194 publications

A three-compartment muscle fatigue model accurately predicts joint-specific maximum endurance times for sustained isometric tasks

A three-compartment muscle fatigue model accurately predicts joint-specific maximum endurance times for sustained isometric tasks

The Influences of Obesity and Age on Functional Performance During Intermittent Upper Extremity Tasks

Sex Differences in Fatigue Resistance Are Muscle Group Dependent

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