Summary
A new computerized dynamometer (the SPARK System) is described. The system can measure concentric and eccentric muscle strength (torque) during linear or nonlinear acceleration or deceleration, isokinetic movements up to 400° · s−1, and isometric torque. Studies were performed to assess: I. validity and reproducibility of torque measurements; II. control of lever arm position; III. control of different velocity patterns; IV. control of velocity during subject testing; and, V. intra-individual reproducibility. No significant difference was found between torque values computed by the system and known torque values (p>0.05). No difference was present between programmed and external measurement of the lever arm position. Accelerating, decelerating and isokinetic velocity patterns were highly reproducible, with differences in elapsed time among 10 trials being never greater than 0.001 s. Velocity during concentric and eccentric isokinetic quadriceps contractions at 30° · s−1, 120° · s−1 and 270° · s−1 never varied by more than 3° · s−1 among subjects (N=21). Over three days of testing, the overall error for concentric and eccentric quadriceps contraction peak torque values for 5 angular velocities between 30° · s−1 and 270° · s−1 ranged from 5.8% to 9.0% and 5.8% to 9.6% respectively (N=25). The results indicate that the SPARK System provides valid and reproducible torque measurements and strict control of velocity. In addition, the intra-individual error is in accordance with those reported for other similar devices.
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References
Farrel M, Richards JG (1986) Analysis of the reliability and validity of the kinetic communicator exercise device. Med Sci Sports Exerc 18:44–49
Gransberg L, Knutsson E (1983) Determination of dynamic muscle strength in man with acceleration controlled isokinetic movements. Acta Physiol Scand 119:317–320
Ingemann-Hansen T, Halkjaer-Kristensen J (1979) Force-velocity relationships in human quadriceps muscles. Scand J Rehab Med 11:85–89
Jacobs I, Pope J (1986) A computerized system for muscle strength evalution: measurement reproducibility, validity and some normative data. NSCA J 8:28–33
Komi PV (1984) Physiological and biomechanical correlates of muscle function: Effects of muscle structure and stretch-shortening cycle on force and speed. Exc Sport Sci Rev 12:81–121
Osternig LR (1986) Isokinetic dynamometry: implications for muscle testing and rehabilitation. Exc Sport Sci Rev 14:45–80
Petrofsky JS, Phillips CA (1986) The physiology of static exercise. Exc Sport Sci Rev 14:1–44
Sapega AA, Nicholas JA, Sokolow D, Saraniti A (1982) The nature of torque “overshoot” in Cybex isokinetic dynamometry. Med Sci Sports Exerc 14:368–375
Thorstensson A (1976) Muscle strength, fibre types and enzyme activities in man. Acta Physiol Scand [Suppl 443]
Thorstensson A, Oddsson L, Karlson E, Seger J (1986) Does acceleration influence the force-velocity relationship of concentric and eccentric concentrations? Med Sci Sports Exerc 18:S63
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Seger, J.Y., Westing, S.H., Hanson, M. et al. A new dynamometer measuring concentric and eccentric muscle strength in accelerated, decelerated, or isokinetic movements. Europ. J. Appl. Physiol. 57, 526–530 (1988). https://doi.org/10.1007/BF00418457
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DOI: https://doi.org/10.1007/BF00418457