Rectus abdominis muscle strength is assessed by a freehand muscle strength test, which can be categorized into six levels, ranging from 0 to 5.
The patient is placed in a supine position and the assessor will touch the rectus abdominis muscle and ask the patient to raise his/her head. If the abdominal muscles do not contract or the patient is unable to raise his/her head, then the muscle strength is at level 0.
If the subject can raise their head and there is abdominal muscle tension, the muscle strength is at the level of grade 1.
If the subject is able to raise the head and neck at the same time in the supine position, the muscle strength of the rectus abdominis is at level 2.
If the subject is able to lift the head, neck, and shoulder blades off the bed in the supine position with appropriate flexion of the hips and knees, the strength of the rectus abdominis muscle is at level 3.
If the participant is able to lift his/her hands flat and lift the shoulder blades and head and neck off the bed at the same time, the Rectus Abdominis muscle has reached level 4.
If the person can hold his/her head with both hands and still perform the movement, the strength of the rectus abdominis muscle is at level 5.
Under normal circumstances, the strength of the rectus abdominis muscle is generally able to reach the level of 5. If the muscle strength decreases, it is necessary to carry out standardized exercises and treatments according to the cause of the disease under the guidance of professional physicians.