In relation to health and fitness, the term ‘prime mover’ refers to a muscle, or group of muscles, that is most in charge of a particular motion of a joint. For a number of joints, there are just a pair of prime mover muscles. However, other joints can have several prime movers and this depends on the motion. In fitness, the concept of prime mover muscles is important as, when performing an exercise, it is vital to know what the prime mover muscle of that exercise are. This is as it will be the one getting the most powerful workout.
Which joints have the most prime mover muscles?
Joints that include rotation as part of their capabilities tend to have a greater number of prime mover muscles as opposed to those with a lot less forms of articulation. For instance:
- In the knee, which bends in one direction, there are only two prime movers. The quadriceps function as the prime mover of the knee extension while the hamstring is responsible for knee flexion.
- Exercises – in which the motion depends mainly on the bending of the knee – will make use of one of these two muscle groups as its primary mover muscle group. That muscle group will therefore benefit the greatest from these exercise.
What does ‘agonist’ mean in terms of exercising?
‘Agonist’, in relation to muscles, refers to a movement in which the muscle(s) provides the major force to complete the movement. In the bicep curl, which produces flexion at the elbow, the biceps muscle is the agonist. In every exercise, the agonist is not the muscle that is shortening (contracting concentrically). In a bicep curl the bicep is the agonist on the way up when it contracts concentrically as well as on the way down when it contracts eccentrically. This is because it is the prime mover in both cases.
The converse of agonist, ‘antagonist’ refers to a movement in which the muscles oppose the agonist. During elbow flexion, where the bicep takes the role of the agonist, the tricep muscle is the antagonist. While the agonist contracts and causes the movement to occur, the antagonist typically relaxes in order not to impede the agonist.
The antagonist doesn’t always relax and another function of this muscle type can be to slow down or stop a movement. This could be seen if the weight used in the bicep curl was very heavy. In this instance, when the weight was being lowered from the top position the antagonist tricep muscle would produce a sufficient amount of tension to assist with controlling the movement as the weight is lowered down. This assist with ensuring that gravity doesn’t accelerate the movement so causing damage to the elbow joint at the bottom of the movement. The tricep becomes the agonist and the bicep the antagonist when the elbow extends against gravity for example in a push up, a bench press or a tricep pushdown.
The correct form for prime mover exercises
There are a number of prime mover exercises that we do every time we hit the gym. To help you get the most of your workout, we thought that we’d give you some hints and tips about how to do the tricep pulldown correctly.
- Fasten a rope attachment to a high pulley. Grip the ropes with a neutral grip and your palms facing each other.
- Stand upright with your torso straight lean slightly forward. Bring your upper arms close to your body and perpendicular to the ground. Your forearms should be pointing up towards the pulley while your hold the rope with your palms facing each other.
- Utilising your triceps, bring the rope downwards as you bring each section of the rope to the side of your thighs. At the end of the movement, your arms will be fully extended and perpendicular to the ground. Your upper arms should always remain stationary on either side of your torso. Only your forearms should move. Breathe out as you perform this movement.
- After maintaining the contracted position for a second, bring the rope slowly up to your starting point. Inhale as you perform this step.
- Repeat for as many repetitions as indicated.
There are several variations to this exercise such as using an E-Z bar attachment as well as a V-angled bar or straight bar.
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