Differences in reciprocal inhibition b/w knee and elbow.

The role of antagonistic muscle activity during maximal and sub-maximal isometric contractions has been examined using Electromyography (EMG) (Baratta et al, 1988). In muscular contractions the “antagonist” muscle actively opposes the “agonist”. For example, during the lifting phase of a biceps curl, the triceps muscles lengthen as the biceps contract. In this case the biceps acts as the agonist and the triceps acts as the antagonist.

Another example is during a leg extension of the knee. Similar to the arm curl, the quadriceps contract and act as the agonists, whilst the hamstrings lengthen and act to be the antagonists.

The moment arm or mechanical advantage at the joint describes the distance from the “pivot point” to the line of action of a force (Kellis & Baltzopoulos, 1997). Research by Kellis & Baltzopoulos (1997) was able to show that joints with greater moment arms have increased antagonist activation.

Muscles are activated in a reciprocal pattern in most voluntary movements (Nielson & Kagamihara, 1991). Reciprocal inhibition causes a reduc

Bicep Sub-max (Ave) 0.397 58 0.416 33

The final limitation of the study is concerned with the lack of variation of joint angles used to measure the amount of antagonist activity produced. Our particular study only used one angle for each joint, which means that the moment arms at the joints were fixed. It is a well known fact that, as the moment arms of muscles change, so to does the level of coactivation in the antagonist muscle (Kellis & Baltzopoulos (1997)). Perhaps the triceps were at a particular angle which gave them a better mechanical advantage compared to the hamstrings and may have been the underlying factor in causing these results. To overcome this, many different joint angles should have been incorporated in order to determine a quality result.

Some topics in this essay:
Kellis Baltzopoulos, Computer Software, Basmajan Banzant, Carolan Cafarelli, Quad AVERAGE, Reciprocal Inhibition, Basmajan Bazant, EMG Baratta, Conclusion Based, EMG Raw, elbow flexion, moment arms, et al, % max, kellis baltzopoulos, sub 1, knee extension, level coactivation, kellis baltzopoulos 1997, maximal sub-maximal, subject 2, % max activation, 1 subject 2, et al 1988, subject 1 subject,