References: (1) Kendall, McCreary, Provance: Muscle Testing and Function (4th Edition). (2) Chek: Scientific Core Conditioning
Anterior trunk flexion by lower abdominal muscles focuses on the ability of these muscles to flex the lumbar spine by flattening the low back on the table, and holding it flat against the gradually increasing resistance provided by the leg-lowering movement.
Performing the Lower Abdominal Strength Test
1. Lay the client supine on the floor or assessment table with their hands are crossed shoulder to shoulder (the picture below illustrates the arms at the side). Allowing the client to have the arms at the side would provide assistance and give a false reading.
2. Place hand under their back at the level of L3 (the umbilicus). A blood pressure cuff can also be used in the same way as the Supine TVA Exercise, taking the starting pressure to 40 mmHg.
3. Assist the client in raising legs to a vertical position, keeping the knees straight. Tightness in the hamstring complex will interfere with obtaining a full starting position.
4. With the legs held perpendicular to the floor, ask the client to produce firm pressure on your fingers by producing a drawing in maneuver and tilting the pelvis posteriorly and maintain the same amount of pressure throughout the test.
5. The client slowly and steadily lowers their legs unassisted. Be careful to watch for compensation through the abdominal wall, seen when the abdominals protrude. Also the head and shoulders should not be lifted during the test.
6. Stop the test at the point where the spine begins to rise off your fingers.
7. Strength is measured based on the ability to keep the low back flat while slowly lowering both legs from vertical. Measure the angle of the legs from the floor. Normal strength would be 100% or 0o.
8. Some text has suggested that females should grade lower than males because of bodyweight distribution (females carry more weight in the lower body), however this may not be valid as suggested by Paul Chek because they still have to carry their lower body weight.
