An investigation into the effects of isometric quadriceps contraction at differing angles of the knee joint on subsequent quadriceps torque curve
Item
- Title
- An investigation into the effects of isometric quadriceps contraction at differing angles of the knee joint on subsequent quadriceps torque curve
- Author(s)
- Hickman Claire
- Abstract
-
ABSTRACTOBJECTIVE: The aim of this study was to establish whether there was any immediate relationship between isometric and isokinetic force production of the knee extensor group, when the isokinetic action followed directly after the isometric contraction. It is postulated that acute responses to exercise are mainly attributable to neural factors influencing the motor pathway and neuromuscular junction. The isometric contraction intervention was therefore being tested for its potential ability to 'warm-up' the nervous system and enhance subsequent force production. The position of the knee joint for the isometric contraction was varied during the testing.
METHOD: 19 asymptomatic male subjects (n=19, mean age=28+/-6.46 years) performed single-epsiode short-duration (5-second) maximal voluntary isometric contraction (MVIC), followed by maximal voluntary isokinetic contraction (MVC) of the quadriceps muscles. This was repeated on three separate occasions, one week apart to minimize any cumulative training effect occurring between test days. On each occasion the isometric contraction occurred at one of three angles of knee joint flexion, either 10°, 40° or 90°, randomly selected. The difference of knee position was intended to establish whether the joint position bore any relevance to final isokinetic torque production. Prior to the three-week trial, reliability of the isokinetic testing equipment was independently confirmed. On two occasions, one week apart, subjects performed isokinetic knee extension without the intervention. Analysis by t-test revealed no significant difference, therefore the data could be regarded reproducible.
RESULTS: The data revealed that there was no significant increase in isokinetic peak torque following a single-episode short-duration MVIC, at any of the three joint angles tested (P>0.05). Correlation of isokinetic and isometric force production yielded a positive relationship at 10° (Pearson r =0.518), 40°(r =0.523) and 90°(r =0.628) of joint flexion (combined Pearson r =0.05) The physiological length-tension relationship was reproduced and established the optimal position, of the three joint angles tested, for isometric force production.
CONCLUSION: It could not be concluded that the isometric intervention had any short-term 'warm-up'effect on the nervous system. Whilst no significant increase in torque was demonstrated in this study, however, certain aspects of strength were highlighted. This information ^could be used by osteopaths wishing to incorporate longer-term strengthening exercise into their patient management plan. - presented at
- British College of Osteopathic Medicine
- Date Accepted
- 0
- Date Submitted
- 1.1.1970 00:00:00
- Type
- osteo_thesis
- Language
- English
- Submitted by:
- 62
- Pub-Identifier
- 13585
- Inst-Identifier
- 1076
- Recommended
- 0
- Item sets
- Thesis
Hickman Claire, “An investigation into the effects of isometric quadriceps contraction at differing angles of the knee joint on subsequent quadriceps torque curve”, Osteopathic Research Web, accessed May 6, 2024, https://www.osteopathic-research.com/s/orw/item/1172