Factors affecting the variability of the torque curves at isokinetic trunk strength testing

doi:10.1016/S0003-9993(98)90204-0

Archives of Physical Medicine and Rehabilitation

Volume 79, Issue 1, January 1998, Pages 33-35

https://doi.org/10.1016/S0003-9993(98)90204-0 Get rights and content

Abstract

Objectives: To evaluate the relation between variability of the torque curves and factors such as age, gender, measurement speeds, and period from low back pain (LBP) onset at isokinetic trunk strength testing.

Design: Observational.

Setting: Hospital.

Patients: One hundred forty-three consecutive LBP patients (acute, subacute, and chronic) who received physical therapy, and 200 healthy volunteer subjects.

Main Outcome Measures: The variability of the torque curves is an indicator of consistency of effort, and was measured as the coefficient of variance (CV) at different measurement speeds in isokinetic trunk flexion/extension strength testing.

Results: The CV was lower in men than in women at the faster measurement speed. LBP patients had higher CV values than healthy subjects. The CV was different according to gender and measurement speed, but not different according to age and periods from LBP onset.

Conclusion: The CV was affected by measurement speed and gender, but not by age or period from LBP onset. Because the CV was higher in LBP patients than in healthy subjects, this value may be usable as an adjunctive index of LBP.

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Cited by (17)

Absolute and relative reliability of isokinetic and isometric trunk strength testing using the IsoMed-2000 dynamometer
2017, Physical Therapy in Sport
Citation Excerpt :
Isokinetic strength testing is a useful approach to assess trunk extension and flexion in healthy individuals as well as low back pain patients (Mueller, Stoll, Mueller, & Mayer, 2012). In order to assess trunk strength many different devices have been developed for standing (Akebi, Saeki, Hieda, & Goto, 1998; Delitto et al., 1991; Guilhem, Giroux, Couturier, & Maffiuletti, 2014; Karatas et al., 2002; Keller, Hellesnes, & Brox, 2001; Kurz, Anders, Walther, Schenk, & Scholle, 2014) or sitting positions (Danneskiold-Samsøe et al., 2009; Dvir & Keating, 2001). Isokinetic (peak torque and workforce) (Delitto et al., 1991) and isometric parameters (peak force and rate of force development or rate of torque development (Beimborn & Morrissey, 1988)) are regularly assessed.
The present study aimed to assess the between day reliability of isokinetic and isometric peak torque (PT) during trunk measurement on an isokinetic device (IsoMed 2000).
Test-retest-protocol on five separate days.
Fifteen healthy sport students (8 female and 7 male) aged 21 to 26.
PT was assessed in isometric back extension and flexion as well as right and left rotation. Isokinetic strength was captured at a speed of 60°/s and 150°/s for all tasks.
For none of the assessed parameters a meaningful variation in PT during test days was observed. Relative reliability (ICC = 0.85–0.96) was excellent for all tasks. Estimates of absolute reliability as Coefficient of Variation (CoV) and Standard Error of Measurement (SEM in Nm/kg lean body mass) remained stable for isometric (6.9% < CoV < 9.4%; 0.15 < SEM < 0.23) and isokinetic mode (60°/s: 3.7% < CoV < 8.6%; 0.08 < SEM < 0.24; 150°/s: 6.9% < CoV < 12.4%; 0.10 < SEM < 0.31). In contrast, reliability between familiarization day and day 1 was lower (6.6% < CoV < 26.2%; 0.10 < SEM < 0.65).
Trunk strength measurement in flexion and extension or trunk rotation in either isometric or isokinetic condition is highly reliable. Therefore, it seems possible to elucidate changes which are smaller than 10% due to intervention programs when a preceding familiarization condition was applied.
Effects of Lumbosacral Manipulation on Isokinetic Strength of the Knee Extensors and Flexors in Healthy Subjects: A Randomized, Controlled, Single-Blind Crossover Trial
2015, Journal of Chiropractic Medicine
Citation Excerpt :
Nonetheless, the wide spread in the data around the mean apparent in all of the measurements, regardless of treatment randomization, can be partially explained by the variability inherent in strength testing. It has been suggested that the lowest amount of intersession variability attainable during repeated MVC/MVICs is a coefficient of variation range of 5% to 10%,35,36 and a standard error of the mean of 5%.37 Although the overall magnitude of the changes in strength post–lumbosacral manipulation was not large enough to overcome this variability, statistically significant changes in measurements of CNS processing have been reported in previous investigations of the physiological effects of SM.28,38
The purpose of this study was to investigate the effect of manual manipulations targeting the lumbar spine and/or sacroiliac joint on concentric knee extension and flexion forces. Torque production was measured during isometric and isokinetic contractions.
This was a randomized, controlled, single-blind crossover design with 21 asymptomatic, college-aged subjects who had never received spinal manipulation. During 2 separate sessions, subjects’ peak torques were recorded while performing maximal voluntary contractions on an isokinetic dynamometer. Isometric knee extension and flexion were recorded at 60° of knee flexion, in addition to isokinetic measurements obtained at 60°/s and 180°/s. Baseline measurements were acquired before either treatment form of lumbosacral manipulation or sham manipulation, followed by identical peak torque measurements within 5 and 20 minutes posttreatment. Data were analyzed with a repeated measures analysis of variance.
A statistically significant difference did not occur between the effects of lumbosacral manipulation or the sham manipulation in the percentage changes of knee extension and flexion peak torques at 5 and 20 minutes posttreatment. Similar, nonsignificant results were observed in the overall percentage changes of isometric contractions (spinal manipulation 4.0 ± 9.5 vs sham 1.2 ± 6.3, P = .067), isokinetic contractions at 60°/s (spinal manipulation − 4.0 ± 14.2 vs sham − 0.3 ± 8.2, P = .34), and isokinetic contractions at 180°/s (spinal manipulation − 1.4 ± 13.9 vs sham − 5.5 ± 20.0, P = .18).
The results of the current study suggest that spinal manipulation does not yield an immediate strength-enhancing effect about the knee in healthy, college-aged subjects when measured with isokinetic dynamometry.
Torque-velocity and power-velocity relationships during isokinetic trunk flexion and extension
2008, Clinical Biomechanics
Citation Excerpt :
They allow measurement of muscular deficiency, which may be of interest in low-back pain rehabilitation (Thorstensson and Arvidon, 1982). Unlike in the case of upper (Valour et al., 2003) and lower limbs (Froese and Houston, 1985; Seck et al., 1995), force– and power–velocity relationships in trunk flexors and extensors during isokinetic exercise have never been established: isokinetic trunk flexor and extensor muscle measurements in previous studies (Akebi et al., 1998; Luoto et al., 1996; Vézirian et al., 1996) included only two or three different angular velocities, making it impossible to assess the force– and power–velocity relationships. Force–velocity and power–velocity relationships are now commonly assessed during isokinetic (Perrine and Edgerton, 1978) and ballistic (Rahmani et al., 1999) single-joint movement and multi-joint cycling movements (Hautier et al., 1996; Vandewalle et al., 1987), and certain indicators of muscle function may be derived from them.
Background. No study has reported the possibility of establishing torque–velocity and power–velocity relationships for both flexor and extensor trunk muscles. The present study therefore sought to assess these relationships during isokinetic exercise.
Methods. Nine healthy male subjects performed series of isokinetic trunk flexions and extensions at six different velocities ranging from 45° s⁻¹ to 120° s⁻¹. Trunk flexor and extensor muscles were, respectively, assessed on two separate days. All experiments used a Biodex dynamometer.
Findings. Torque–velocity relationships were significantly well described by a linear relationship for both trunk flexor (P < 0.01; r = 0.92–0.99) and extensor muscles (P < 0.05; r = 0.82–0.97) in all subjects. Power–velocity relationships exhibited a parabolic shape for all subjects (P < 0.05; r = 0.96–0.99) for both muscle groups.
Interpretation. Results showed that trunk muscle torque– and power–velocity relationships can be assessed during isokinetic exercise. The findings were in agreement with previous studies of lower and upper limbs. This kind of measurement can therefore be applied in assessing low-back pain patients during rehabilitation.
Muscle sparing thoracotomy: A biomechanical analysis confirms preservation of muscle strength but no improvement in wound discomfort
2000, European Journal of Cardio-thoracic Surgery
Isokinetic trunk strength in acute low back pain patients compared to healthy subjects: A systematic review
2021, International Journal of Environmental Research and Public Health
Knee Extensor and Flexor Torque Variability during Maximal Strength Testing and Change in Knee Pain and Physical Function at 60-Mo Follow-Up: The Multicenter Osteoarthritis Study (MOST)
2021, American Journal of Physical Medicine and Rehabilitation

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ArticleFactors affecting the variability of the torque curves at isokinetic trunk strength testing☆

Abstract

Effect of increasing back and abdominal muscle strength on low back pain

Res Q

Trunk-muscle strength during concentric and eccentric contraction: a comparison between healthy subjects and patients with chronic low-back pain

J Spinal Disord

A quantitative study of muscle factors in the chronic low back syndrome

J Am Geriatr Soc

Measurement of abdominal and back muscle strength with and without low back pain

Scand J Rehabil Med

A new method of quantitative measurement of abdominal and back muscle strength

Spine

A quantitative study of trunk muscle strength and fatigability in the low-back pain syndrome

Spine

Isokinetic evaluation of trunk muscles

Spine

Article
Factors affecting the variability of the torque curves at isokinetic trunk strength testing☆