Two methods for determining trunk extensor endurance

Jørgensen, Kenneth Mølbjerg; Nicolaisen, T

doi:10.1007/bf00423210

Cited by 59 publications

(37 citation statements)

References 10 publications

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“…The intraclass correlation coef®cients were satisfactory for both inter-trial and test±retest reliability. Our results are similar to the reliability results reported for the Sorensen trunk endurance test [11,12,29], a test similar to TLS in that subjects sustain a submaximal effort for as long as possible. Our reliability ®ndings were substantially higher than those reported for an isokinetic endurance test of the trunk extensors [14].…”

Section: Discussionsupporting

confidence: 93%

Timed Loaded Standing: A Measure of Combined Trunk and Arm Endurance Suitable for People with Vertebral Osteoporosis

Shipp

Purser

Gold

et al. 2000

Osteoporosis International

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Chronic back tiredness or fatigue is a common complaint of people who have a history of osteoporotic vertebral fracture. Trunk muscle endurance has not been studied in people with vertebral osteoporosis, partly due to the lack of assessment tools. We developed a measure of combined trunk and arm endurance suitable for people with vertebral osteoporosis, timed loaded standing (TLS). TLS measures the time a person can stand while holding a two-pound dumbbell in each hand with the arms at 90 degrees of shoulder flexion and the elbows extended. Intraclass correlation coefficients (ICCs) for same day inter-trial and six to ten day test-retest reliability were 0.89 (lower bound 95% confidence interval [LB 95% CI] 0.79) and 0.84 (LB 95% CI 0.68), respectively, in a sample of 21 older women with no known osteoporosis. In 127 women with vertebral fractures, the ICC for same day inter-trial reliability was 0.81 (LB 95% CI 0.75). In a sub-sample of 30 of these women with vertebral fractures, the six to ten day test-retest reliability was 0.85 (LB 95% CI 0.75). Moderately strong and statistically significant (p < or = 0.05) correlations were found between TLS and sixteen of eighteen measures of physical impairment and function. Functional reach distance, gait velocity, MOS-36 Physical Function Subscale, shoulder flexion strength, and six minute walk distance were most strongly associated with TLS time. Women with vertebral fractures who endorsed having back tiredness when standing and working with the arms in front of the body, sitting to rest because of back tiredness or pain, and planning rest periods because of back tiredness or pain had significantly lower TLS times. TLS is a simple, safe physical performance measure of combined trunk and arm endurance that demonstrates acceptable reliability (inter-trial and test- retest) and concurrent validity.

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Section: Discussionsupporting

confidence: 93%

Timed Loaded Standing: A Measure of Combined Trunk and Arm Endurance Suitable for People with Vertebral Osteoporosis

Shipp

Purser

Gold

et al. 2000

Osteoporosis International

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“…The significant interaction effect of the entropy between muscles and groups following treatment during the one-minute back extension test supports the characteristics of the recorded signals that occurs with fatigue (Roy et al, 1989). Exercises for graded activity programs can be used to increase trunk muscle endurance and to decrease pain (Jorgensen & Nicolaisen, 1986;Jorgensen & Nicolaisen, 1987). Undoubtedly, other muscles participated in the load sharing during the testing as well as when subjects performed the intervention exercises.…”

Section: Sensitivity Of Surface Electromyography Analysissupporting

confidence: 54%

Nonlinear Analysis of Surface Electromyography

Sung¹

2012

EMG Methods for Evaluating Muscle and Nerve Function

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EMG Methods for Evaluating Muscle and Nerve Function 134that the signal must be interpreted as "noise." The noise is due to the interaction between a particular muscle and all other biomechanical "units" of the body. In many cases, the power spectrum follows an algebraic dependence P(f) ~ 1/f. The case =0 corresponds to "white noise" while =2 characterizes diffusive Brownian motion. Therefore, the MF of the EMG power spectrum is sensitive to physiological manifestations of muscular dysfunction as an alternative assessment tool to identify muscle fatigue (Mannion et al., 1997b;Roy et al., 1997). H o w e v e r , t h e r e i s a l a c k o f r e s e a r c h t h a t c o m p a r e s t h i s t o o l w i t h o t h e r n o n l i n e a r measurements based on pain level or dysfunction. During a fatiguing contraction, a compression of the power spectrum of the EMG signal to lower frequencies is typically observed (Lindstrom et al., 1974). This phenomenon is measured during a contraction as a decrease in the MF of the EMG signal. Individuals with better endurance than others exhibit a less precipitous decay rate of the MF (Mannion et al., 1997b). Thus, it would be necessary to compare the results between Shannon entropy levels of the EMG and MF of the spectral quantities following intervention to enhance outcome measurements.Other results indicated that subjects with LBP show less fatigue than healthy subjects (Humphrey et al., 2005;Mannion et al., 2001). Thus, despite considerable efforts by many researchers, a link between MF and musculoskeletal pain/dysfunction remains elusive. Moreover, the surface EMG is not a scientifically acceptable tool for the diagnosis of pain/dysfunction, and further studies are recommended to assess the specificity and sensitivity of surface EMG (Pullman et al., 2000). Therefore, a clinical diagnosis and evaluation of LBP is still elusive, and the efficacy of therapeutic intervention and assessment for LBP cannot be tested reliably. The power spectrum analysis provides an objective and noninvasive assessment of muscle function since EMG changes are associated with fatigue (De Luca, 1984;Mannion et al., 1997a). However, contradictory results have been reported in studies using EMG as an outcome measure. The power spectrum has a limited dynamic range, and the change of the MF does not reflect such long-time correlations. New methods must be designed to capture biologically important characteristics from noisy time series. Researchers using nonlinear time series analysis have developed several mathematical tools to reveal the presence of power-law time correlations. Investigations of physiologic time series have led to the understanding that some degree of noise is necessary for the proper functioning of biological systems (Belair et al., 1995b;Glass, 2001;Strogatz, 2001). These systems must respond to external stimuli that may vary both in strength and time scale by many orders of magnitude. The "degree of irregularity" of time series can be quantified by computing the (information) entropy of...

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“…The BSME is considered to elicit a muscular contraction of 20-75% of maximal volitional contraction (MVC) (Jørgensen and Nicolaisen 1986;Mannion and Dolan 1994;Smidt and Blanpied 1987) which is influenced by body type and conditioning level of the subjects (Jørgensen and Nicolaisen 1986). Muscular contraction between 20% and 75% of MVC should reduce or occlude erector spinae muscle blood flow (Humphreys and Lind 1962;Jørgensen 1997).…”

Section: Introductionmentioning

confidence: 99%

Reliability of erector spinae oxygenation and blood volume responses using near-infrared spectroscopy in healthy males

Kell

Farag

Bhambhani

2004

European Journal of Applied Physiology

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The purpose of this investigation was to (1). describe the trends in oxygenation (OXY) and blood volume (BV) of the right and left paraspinal muscles during the Biering-Sorensen muscle endurance (BSME) test using near infrared spectroscopy (NIRS), and (2). assess the test-retest reliability of OXY and BV changes during the BSME in healthy males. Seventeen healthy males [age=28.4 (9.8) years, height=1.75 (0.05) m, body mass=82.7 (9.1) kg; mean (SD)] completed two BSME trials within 1 week. NIRS probes were placed bilaterally at lumbar 3. The test was performed with the subject in the prone position using the following protocol: 2 min baseline, BSME, and 4 min recovery. The delta and range values of OXY and BV were used for analysis. Acceptable intra-class correlations were observed for endurance time and all the NIRS variables at the point of fatigue and at each 10% segment of the BSME during the two trials. Bland-Altman plots confirmed the reproducibility of the bilateral NIRS responses of the paravertebral muscles. The BV responses were more reliable than the OXY responses during the two trials. The OXY and BV responses of the paravertebral muscles during static contractions can be measured reliably using NIRS. Future studies should focus primarily on BV for analysis.

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Two methods for determining trunk extensor endurance

Cited by 59 publications

References 10 publications

Timed Loaded Standing: A Measure of Combined Trunk and Arm Endurance Suitable for People with Vertebral Osteoporosis

Timed Loaded Standing: A Measure of Combined Trunk and Arm Endurance Suitable for People with Vertebral Osteoporosis

Nonlinear Analysis of Surface Electromyography

Reliability of erector spinae oxygenation and blood volume responses using near-infrared spectroscopy in healthy males

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