Dysfunctional Supine Curl Up Test

Anatomy and Biomechanics:

The inability to perform a supine curl up is often due to an ERS dysfunction in the lower thoracic spine or upper lumbar spine and should always be addressed first before attempting to retrain this movement test. (Refer to Module #3). When patients perform abdominal “crunches” with the hips and knees flexed they are working the abdominals in a shortened position and often results in substitution by the hip flexors. We need to consider that working the abdominals with the hips and knees flexed is not really functional as we need abdominal tension/tone through the full range of flexion of our spine. This is especially true when we are standing upright with the hips and knees in a neutral or extended position. Often what we see in the clinic are people who are unable to perform an unassisted full range supine curl up without extending the lumbar spine when the hip flexors kick in at mid range.

Working the abdominals eccentrically with the assistance of a belt helps to not only activate the abdominals throughout the full spinal flexion range of motion, but also can be used to segmentally self mobilize the thoracolumbar spine for flexion. In addition, this exercise stretches the thoracolumbar spinal extensors that are prone to hypertonicity as a response to abnormal afferent information in the lower quarter. We see this especially in patients complaining of low back pain.

When working the abdominals eccentrically, emphasis is placed on instructing the patient to posteriorly translate the spine segmentally from below up and to stop when they reach a spinal level that they are unable to flex (posteriorly translate). This exercise is therefore ideal for patients with spondylolisthesis who need to strengthen their abdominals and avoid exercises that can cause or contribute to anterior translation of L5 or L4. This exercise is also helpful for patients with lumbar central and lateral stenosis as spinal flexion increases spinal canal volume and opens the intervertebral foramen respectively.

Substitution Patterns to watch out for during retraining:

When instructing a patient in this exercise focus on encouraging the patient to draw the belly in and push their spine back to maximally posteriorly translate the spine at each spinal level beginning at L5 and working segmentally up the spine. Look for a loss of flexion at a spinal level when there is a tendency to extend rather than flex through this level. When this occurs the patient should be instructed to return upright by curling back up to the starting position and repeat the exercise. The patient should be able to gradually lower themselves further and further until eventually they are able to touch the floor.