// Exercises under the microscope: Triceps kickback
by Tony Podpera
The triceps kickback is one of the most commonly used triceps exercises in health clubs and fitness facilities, and is chosen largely because it is so simple to set up and perform. But is it really the best triceps exercise for you, your clients or your class? It is worth revisiting the basics behind this exercise to find out.
Range of motion
Many claim that kickbacks are effective because the greatest resistance is applied to the muscles at the point of maximal contraction (that is, when the arm is fully extended). While greatest resistance does indeed occur at the point of maximal contraction, which can be good, that’s really the only place any contraction or resistance does occur, which can be bad.
During the first part of the exercise, when the angle of the elbow opens from 90 degrees to about 135 degrees, the weight in the hand travels back mostly horizontally.
This doesn’t stress the triceps. It’s only when the weight travels more vertically than horizontally that the triceps start to work hard (photo 1). At this stage, though, there are only a few degrees of motion left before the elbow extends completely at 180 degrees. The exercise, therefore, operates effectively through a very small range of motion.
An exercise performed through a shorter range of motion, whether or not this range involves maximal contraction, tends not to stimulate as much muscle contraction as one performed through a longer range. This short range of motion can be improved slightly by tilting the upper arm upwards during the exercise instead of keeping it horizontal (photo 2). This will mean that there is more extension left in the elbow, and therefore more range for contraction as the weight starts to travel vertically and the load increases. However, the difference is not great and may not be worth the extra effort to adjust one’s body position so the upper arm can adopt the required tilt.
In the eccentric phase of the exercise, flexing the elbow maximally (by bringing the weight to the shoulder) does not effectively increase the range of motion. This is because it is a predominantly horizontal movement of the resistance and, therefore, when the elbow extends again the triceps are not really doing much work at all. Indeed, it may even result in less work because this method can tend to increase the use of momentum through the movement.
Kickback with a cable apparatus can impose a resistance on the triceps from full elbow flexion to full extension. However, one-armed cable work for the triceps can introduce stability problems for the working arm and this can significantly affect the efficiency of the exercise.
The role of supporting musclesAt the end of a triceps kickback the elbow is fully extended, effectively meaning that the arm, with a weight attached to the very end, is being held horizontal by the small muscles around the rear of the deltoid. This is a lot of work for a relatively small, and often untrained, muscle group and fatigue often sets in quickly during a set of kickbacks. When this happens, the upper arm starts to sag towards the floor, the vertical movement of the weight (which is when the triceps work) becomes a more horizontal movement and the exercise becomes next to useless.
In addition to fatigue, using too heavy a weight will also cause the arm to sag. As a heavy weight is extended backward in a kickback, the lever lengthens very quickly, the relative weight being supported by the rear deltoids skyrockets and the supporting muscles are simply not capable of holding the arm horizontal. As the weight travels further out, the rear deltoids can’t take it, the elbow sags and, once again, the weight travels horizontally, robbing the triceps of any real chance to work against a vertical resistance (photo 3).
Given the very small range in which a triceps kickback provides effective muscle contraction, even a small sag in the elbow can rob the exercise of its effectiveness.
Weight considerationsUsing a heavy weight renders a kickback useless, so it’s better to use a light weight which enables our supporting muscles to support the arm in the correct position as the exercise is performed. The trouble is that using a light weight doesn’t really recruit as many motor units in the triceps when the exercise is performed (only that amount of muscle fibres that absolutely have to contract in an exercise will do so; the others look like they’re contracting, but are just along for the ride). So, use too heavy a weight and the support muscles can’t cope, and too light a weight and the triceps don’t get stimulated. This is a built-in limitation with triceps kickbacks which fitness professionals must consider before prescribing them.
Is it worth exercising one arm at a time?
For the average participant, there are very few exercises that are worth doing one arm at a time. Exercising in this manner takes the participant twice as long to work a muscle group as performing a double-arm exercise would do, and uses almost twice the energy – so it had better be worth it! Unfortunately, kickbacks have to be performed one arm at a time as doing both arms at once would be too awkward. Nevertheless, the same principle applies – unless there is a distinct advantage in doing a kickback, it will be more efficient to pick a triceps exercise that uses two arms at once. (Hopefully, there are no personal trainers out there using kickbacks with clients because they take twice as long!)
So what does this mean?This means that triceps kickbacks are a little more limited in their application than some of us might think. They can’t be performed effectively with a heavy weight so they’re not that good for triceps strength or size. They can be performed with a light weight but the triceps may not be taxed sufficiently to adapt. They work through a very short range of motion, and they take twice as long to perform as an exercise that works the triceps two arms at a time.
However, triceps kickbacks are quick and easy to set up and can be done anywhere. They could also be more effective at working the triceps after this muscle group has already done some work (so the triceps are partially fatigued but the support muscles may not be; for example, after a set of push ups). Triceps kickbacks can be a very useful exercise in group fitness classes where equipment is limited, set-up time is short and some pre-exhaustion of the triceps may have taken place. In a gym setting, however, their application is limited and a trainer should ensure that there are not more effective and efficient options that can be used to work the triceps before prescribing this exercise.
Tony is a Canberra-based fitness instructor. He began bodybuilding in the early 1980s and has advised clients on weight training issues for 20 years. He started teaching group fitness classes in 1994.
NETWORK MAGAZINE • WINTER 2006 • PP28-30