Start with 3 questions to think of an effective exercise for your goal:
What is the goal of the motion to be performed? (Where does the muscle attach and what does it do?)
What direction is the resistance coming from?
- free-weights = gravity = straight down
- cable/tubing- direction the cable or tubing is applied
What position must I be in to appropriately align my goal motion against the resistance?
- Resistance should be in the same plane, directly opposing the motion.
Then 3 actions to perform the exercise:
Stabilize- Choose the proper body alignment and maintain it.
Primary stabilizers:
- Spine
- Closest joints above and below the joint that is moving or holding the weight.
Secondary stabilizers:
- All other joints.
Path of Motion - Monitor and maintain the path of motion determined by your goal. Any other motion may decrease effectiveness or make the exercise unsafe.
Range of Motion- How far you move is determined by the joint and muscle involved.
Anatomical factors:
- mechanical disadvantage
- ability to maintain adequate contraction (length-tension ratio)
- neuromuscular control
