Type III somatic dysfunction

Vertebrae normally move in defined directions. When you bend forward, they flex; when you lean to the side, they side-bend; and when you turn your body, they rotate. IMT considers movement in these three planes—forward and backward, side to side, and rotation—to be normal.

Type III departs from this pattern of movement. Rather than rotating around an axis, a vertebra has slid forward or sideways over the bone below it in a parallel shift. It is similar to pushing a book to one side on a desk. This approach calls it shear, or subluxation (Chiropractic vertebral subluxation). Sharon Weiselfish-Giammatteo, who developed IMT, organized and taught the long-standing chiropractic term “subluxation” as the concept of Type III somatic dysfunction.

IMT explains that shear can be identified at the superior and inferior surfaces of a vertebra, the spinous process, the pedicles, and the transverse processes. It holds that this can occur not only in the spine but in any joint in the body. Examples involving limb joints include the following.

• Pelvis: When a shift to one side produces lateral shear, the femoral head is compressed. When palpating the greater trochanter at the side of the hip, its convex curve is reduced.
• Knee: The upper surface of the tibia may be displaced outward.
• Ankle: The tibia may be displaced backward over the talus.
• Wrist: The carpal bones may be displaced forward when the wrist is extended.

Type I somatic dysfunction involves two or more vertebrae rotating and side-bending in an upright posture, while Type II somatic dysfunction involves a single vertebra rotating and side-bending in a flexed or extended posture. Because both involve rotation around a defined axis, their direction can be interpreted through the pairing of rotation and side-bending according to Fryette's laws.

Type III has no known physiological axis, making it difficult to identify by interpreting rotation and side-bending. IMT therefore assesses it separately and addresses it differently according to the pattern of displacement. This approach holds that when a bone is displaced, the joint's paths of movement in the three planes are blocked, so joint balance must first be restored before normal movement can return.

The fifth lumbar vertebra (L5) sits above the pelvis and supports the entire spine. IMT explains that L5, which meets the stable sacrum, must rotate and side-bend more than other vertebrae to compensate for that stability. Because the lumbosacral junction accounts for a large share of lower-back movement, this approach holds that substantial forces are also concentrated there, making it prone to slipping forward. It regards forward slippage of L5 as a typical anterior shear at the lumbosacral junction and also distinguishes cases of sideways displacement (Lumbosacral junction).

Integrative Manual Therapy views this misalignment where the lumbar spine meets the sacrum as a representative presentation of Spondylolisthesis. However, spondylolisthesis as used in medical settings is a diagnosis confirmed by imaging, whereas Type III in IMT is a manual therapy classification assessed by hand, so the two terms are not synonymous.

IMT does not view Type III as a problem that can be resolved simply by relaxing muscles. Unlike Muscle energy technique, which reverses rotation and side-bending, it describes using a Type III technique adapted from myofascial release to guide the displaced joint back toward its original position (Articular fascial release). IMT explains that this dysfunction requires a more delicate approach. The aim is not to snap a bone into place in one go, but to restore joint balance so that normal movement in all three planes becomes possible.

• Avoid sitting in the same position for too long. The longer you remain settled in one spot, the longer a single level in your lower back stays under pressure. Get up and take a gentle walk every 30 minutes to one hour.
• Go slowly with exercises that twist your lower back. Rather than forcing a twist in an uncomfortable direction, move within a comfortable range.
• Keep heavy objects close to your body when lifting. This reduces the forward-directed force on the fifth lumbar vertebra.
• Tell your practitioner which movements feel uncomfortable. Being specific about which movements feel restricted and whether you feel shifted to one side can help with the assessment.

If pain or numbness and tingling radiating into your leg are getting progressively worse, your leg feels weak, or your sensation related to urination or bowel movements changes, seek a diagnosis from a medical professional before receiving manual therapy. This is especially important immediately after a fall or accident.