The good morning exercise is a compound exercise that engages a number of muscle groups in various ways. The exercise is executed by placing a barbell across the rear of shoulders and bending at the hips until your torso is parallel to the floor while keeping the back straight. Return to the starting position to complete a single repetition. The exercise gained its name because the motion resembles the act of bowing in greeting.
Target Muscles
The muscles primarily worked through the good morning exercise are the hamstrings on the upper rear of the legs. The hamstrings are responsible for flexion and rotation of the knee as well as extension of the hips. Hamstring strength is important to a number of sports and activities because it supports all movements across the knees.
Synergists
A synergist muscle group is a muscle that assists another to accomplish a given movement. Synergists involved in the good morning exercise include the gluteus maximus of the butt and the adductor magnus on the inner thigh. The gluteus maximus is responsible for extension, rotation and inward and outward movements of the hips. The adductor magnus is a small muscle that also assists in all movements of the hips.
Stabilizers
Stabilizers are muscles that aid in an exercise by contracting isometrically to provide support to the joints that are actually moving. The stabilizers of the good morning exercise are the small but important erector spinae of the lower spine. The erector spinae provide movement and structure across the length of the spine. Strong erector spinae contribute to a healthy posture and natural movement.
Warning
The good morning exercise could place excess stress on the lower spine and cause significant injury if done incorrectly. Start with a very low weight and be sure that the back stays straight and maintains its natural curve throughout the exercise.