Most people seem to think that plyometrics is only jump exercises that involve the legs. This is far from the total picture since plyometrics can take various forms. You can do plyometrics for the arms, midsection and/or total body. The choice depends upon which actions are in need of improvement and which limbs or body parts are involved.
In addition, plyometrics, especially explosive plyometrics, does not always have to be in the form of jump exercises. You can do plyometrics with medicine balls, weighted implements which include barbells, dumbbells and kettlebells, Active Cords and specially constructed devices.
The key element, to ensure that the exercise is truly plyometric, is that you elicit the stretch reflex. It should not however, be a slow acting, full range of motion stretch and contraction movement. It should entail an involuntary forced stretch with maximum tension on the muscle and a quick switch to the muscle/tendon shortening phase.
This stretch-shortening action is exemplified in the depth jump, which is usually executed by the legs, but which can also be done with the arms, as for example, from the push up or handstand position. These are excellent exercises to improve specific sports abilities.
Active Cords are also used extensively in the execution of explosive moments that duplicate specific actions seen in execution of various sports skills. Because of the tension that you can create in the cords, you can produce a strong involuntary stretch with great muscle tension prior to executing a switch to fulfill the shortening phase of the stretch- shorten concept.
Time and space does not permit going into many of the various exercises that can be done. Because of this I strongly recommend reading Explosive Plyometrics for more details on what constitutes explosive plyometrics and the various exercises and types of equipment that can be used.