How to measure muscle imbalance?

Currently, we can mention two most commonly used ways to measure muscle strength and consequently indicate muscle imbalance, they are: 1 repetition maximum test (1RM) and the isokinetic dynamometry.

A possible alternative for the evaluation of strength and the one repetition maximum test (1-RM), which is the most widely used to evaluate the dynamic force, and as a practical method, low cost and apparently safe for most people (Dias et al, 2005;. VERDIJK et al., 2009). One repetition maximum refers to maximum load lifted once and correctly, while conducting a standardized exercise weight lifting (McArdle et al., 1996; QUEIROGA, 2005).

To identify the peak torque through the 1 RM test is done by calculating: Assuming the leg weighs 6.1% of total body mass, is calculated. To accomplish the correction of the gravity, the weight value is subtracted from the leg flexor added to the bank and bank extender. Soon after, the values ​​were multiplied by 9.8 m / s2 (corresponding to acceleration of gravity), thus transforming the load of exercise in weight. This weight, in turn, was multiplied by the length of the tibia, thereby providing the torque information. The torque was found divided by the weight of the individual, in order to find values ​​comparable among the participants. The reason agonist / antagonist was calculated by dividing the torque flexor extensor torque, with the result multiplied by 100 (Winter, 1990).

Bilateral accurate comparison is probably one of the facets that most distinguishes isokinetic dynamometry of the other reviews, this, has as its objective to evaluate through a Isokinetic muscle strength at an angular velocity continues, and has a specific medico-legal role. This derives from the sensitivity of the device, which is far superior to human skill. Using the maximum torque measured by this assessment, we can identify the muscle imbalance of the involved joint (Dvir, 2002).

To measure the muscle imbalance of the knee, it is necessary to divide the maximum torque of the extensor and flexor multiplied by 100. To be considered a balance to the muscle force, the result should be between 60 and 70%, with values ​​below 60% will mean a more weak flexor imbalance and if the amount is above 70% show an imbalance extenders (passion, et al. 2004).

In a study conducted by Sapega (1990), was established parameters to identify muscle imbalances between members, which were divided in healthy subjects in three points:

  1. Difference in up to 10% can be considered normal;
  2. The imbalance between 11 and 20% is possibly abnormal;
  3. imbalance in more than 20% is probably abnormal.

According to the author mentioned above, when imbalances exceed 20%, indicated that the individual is away from physical activities in order, prevention of injury. Already in cases of injury, infection, after treatment, and surgical or not, the return to light activities can be released from the 30% deficit or less, and strenuous activities of 20% or less.

 video about isokinetic dinamometer: