Isotonic (exercise physiology)

Isotonic (exercise physiology)

In an isotonic contraction, tension rises and the skeletal muscle's length changes. Lifting an object off a desk, walking, and running involve isotonic contractions.

There are two types of isotonic contractions: (1) concentric and (2) eccentric. In a concentric contraction, the muscle tension exceeds the resistance and the muscle shortens. In eccentric, the muscle lengthens due to force greater than which the muscle can produce.

Concentric

This type is typical of most exercise. The external force on the muscle is less than the force the muscle is generating - a "shortening" contraction. The effect is visible during the classic bicep curl.It is also used in volleyball

Eccentric

There are two main features to note regarding eccentric contractions. First, the absolute tensions achieved are very high relative to the muscle's maximum tetanic tension generating capacity (you can set down a much heavier object than you can lift). Second, the absolute tension is relatively independent of lengthening velocity. This suggests that skeletal muscles are very resistant to lengthening.

Muscle injury and soreness are selectively associated with eccentric contraction (Fridén et al. 1984; Evans et al. 1985; Fridén and Lieber, 1992). However, muscle strengthening may be greatest using exercises that involve eccentric contractions.

ee also

* Isometric exercise (contraction, no movement)
* Stretching (passive, no contraction)

External links

*


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Isotonic — The term isotonic may refer to; * Isotonic muscle exercise and Weight training * Isotonic (exercise physiology) for the term associated with muscle contraction * An isotone in nuclear physics * Isotonic solutions, solutions that have equal… …   Wikipedia

  • isotonic — 1. Relating to isotonicity or isotonia. 2. Having equal tension; denoting solutions possessing the same osmotic pressure; more specifically, limited to solutions in which cells neither swell nor shrink. Thus, a solution that is isosmotic with… …   Medical dictionary

  • Isometric exercise — or isometrics are a type of strength training in which the joint angle and muscle length do not change during contraction (compared to concentric or eccentric contractions, called isotonic movements). Isometrics are done in static positions,… …   Wikipedia

  • Musculoskeletal physiology — is the branch of physiology which addresses the processes of musculoskeletal system.[1] In subclassifying musculoskeletal physiology, MeSH emphasizes the division between phenomena and processes . It is also possible to emphasize the division… …   Wikipedia

  • Muscle Atrophy Research and Exercise System — Test subject seated in the MARES human restraint system and using the linear adapter to exercise his arms. The Muscle Atrophy Research and Exercise System (MARES), part of the Human Research Facility (HRF), will be launched in a stowed position… …   Wikipedia

  • Weight training — This article is about strength training using weight (gravity) to generate resistance to contraction. For basic principles on increasing the strength of muscles, see strength training. A complete weight training workout can be performed with a… …   Wikipedia

  • Strength training — This article is about the basic principles to train muscular strength. For strength training using free weights or weight machines, see weight training. The lat. pulldown, which strengthens the arms and back Strength training is the use of… …   Wikipedia

  • Muscle contraction — See also: Twitch and Tremor Top down view of skeletal muscle Muscle fiber generates tension through the action of actin and myosin cross bridge cycling. While under tension, the muscle may lengthen, shorten, or …   Wikipedia

  • Lactic acid — L Lactic acid …   Wikipedia

  • Exertion — is a concept describing the use of physical or perceived energy. It normally connotates a strenuous or costly effort related to physical, muscular, philosophical actions and work. Contents 1 Physical 2 Medical 3 …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”