Type I somatic dysfunction

Fryette's laws state that when the spine side-bends in a neutral position without flexion or extension, the vertebrae rotate in the direction opposite to the side-bending (the first law). For example, when the upper body bends to the right, the vertebrae rotate to the left. Rather than a single segment moving on its own, several adjacent segments move together as a group. In integrative manual therapy, this pattern is called Type I motion.

Type I somatic dysfunction occurs when a group that has moved together in this way fails to return to normal and remains fixed in that position. Two or more consecutive segments become fixed as a single unit, with rotation and side-bending in opposite directions.

What are its characteristics?

• Several segments are involved together. Unlike Type II somatic dysfunction, which affects only one segment, several adjacent spinal segments are restricted in the same pattern. This approach also considers it possible for a single-segment Type II somatic dysfunction to be present within a Type I group.
• It is assessed in a neutral position. Displacement is assessed with the spine in a neutral position, without forward or backward movement, rather than in flexion or extension.
• Long muscles are thought to hold the pattern in place. This approach explains that excessive tension in the long muscles running along the spine that contribute to side-bending maintains this pattern. It is interpreted as an adaptive response through which the body tries to compensate for an imbalance elsewhere.

How is it identified?

With the recipient lying face down in a neutral position, the practitioner gently presses through the muscle layers on either side of the spine to locate bony projections (transverse processes) that are more prominent posteriorly. If two or more consecutive segments are prominent on the same side, they are assessed as rotated toward that side, with side-bending in the opposite direction. For example, if the right side is prominent, the group is considered rotated to the right and side-bent to the left. Details of this assessment procedure can be found under Positional diagnosis.

How do Types I, II, and III differ?

Integrative manual therapy also uses a classification called Type III. This refers to a state in which a vertebra is displaced as though sliding forward or sideways, without a normal physiological axis of rotation. This approach cites forward slippage of the fifth lumbar vertebra as a representative example and addresses it using a modified myofascial release technique. It is classified separately from Types I and II because the position itself has shifted, rather than showing a coupled pattern of rotation and side-bending. A similar medical concept is Spondylolisthesis.

Type I somatic dysfunction often presents as stiffness and aching across a broad area of the upper or lower back, rather than at one specific point, with a sensation of being curved to one side. When bending or rotating the trunk to one side, the range of motion may also feel more limited than on the other side.

Integrative manual therapy views this state as an adaptive response that the body develops to compensate for tension elsewhere. Rather than simply releasing the displaced region, practitioners therefore also look for a primary dysfunction originating in segments above or below it. If the cause is not addressed, the spine is considered likely to return to its previous compensatory pattern. In the lower back, protective spasm of the latissimus dorsi is described as often producing a pattern similar to Type I dysfunction, so associated soft-tissue tension is also frequently assessed (see Protective muscle spasm).

• Try bending to each side. Slowly bend your trunk to the right and left within a comfortable range, and notice whether there is a difference in range of motion between the two sides.
• Avoid standing or sitting with your weight consistently shifted to one side. Reduce habits such as always crossing the same leg or carrying a bag on the same shoulder, and try alternating sides.
• Try stretches for the sides of your trunk. From a comfortable position, reach an arm overhead and slowly stretch your side. This helps gently engage the side-bending muscles that this approach considers problematic.
• Relax during treatment. In this approach, correction from the ninth thoracic vertebra through the lumbar spine is generally performed in a side-lying position, while the first through ninth thoracic vertebrae are treated in an upright seated position. When lying on your side, position yourself with the concave side of the curve facing down. After the practitioner moves your legs to position you, gently exert force for about 6–10 seconds and then relax, repeating this three or four times. Even as your position changes, keep your body relaxed and let the practitioner guide you comfortably.

• You notice asymmetry in your body that becomes increasingly obvious over time, to the point that it is visibly apparent
• You also have pain or numbness/tingling radiating toward your side or leg
• You have persistent back pain along with fever or unexplained weight loss
• Spinal movement suddenly becomes restricted after trauma or an impact

These signs may indicate something other than simple posture-related muscle tension, so tell your practitioner or a professional first and have your condition accurately assessed.