By Eric Dalton – http://erikdalton.com/a-system-is-as-strong-as-its-weakest-link/

The past few Technique e-Newsletters have examined Descending Syndromes– cervicocranial disorders affecting pelvic alignment – and Ascending Syndromes – lower extremity imbalances manifesting as head and neck pain (Fig. 1). But sometimes it’s hard to find the “key” perpetrator of the imbalance. If in doubt, I usually begin by performing two simple tests…the Bruger and Derifield. Bruger Test: Brace the client’s forehead with your left hand while your right fingers and thumb gently palpate the suboccipitals…standing and sitting. If tension/tightness eases when the client sits, then the client’s neck or head pain may be coming from lower quadrant imbalances (ascending syndrome). Derifield Maneuver: With client prone (feet off table), place each thumb under the medial malleoli and ask the client to slowly begin rotating the head side-to-side. If leg length changes when the head turns right, one should suspect cervical spine dysfunction (usually on the right side). If turning left creates change, examine and correct head and neck imbalances and recheck.

Common Compensatory Pattern Figure 2 illustrates a common postural imbalance pattern seen daily in a clinical setting. Although this lower quadrant disorder can manifest from ascending or descending origins, it usually indicates a breakdown in one or more of the body’s four major spring systems (Box 1). (See Don’t Get Married articles @ Erik Dalton Articles for complete description of Spring Systems) It’s easier to visualize the asymmetrical leg, hip and low back pattern in figure 2 as an ascending syndrome with the dropped arch as the root of the problem. However, this strain pattern can come from either direction. For example, a tight right iliopsoas (possibly from right motor dominance), may reciprocally weaken the ipsilateral gluteus maximus disrupting function in the Posterior Spring System (PSS). Notice how the short iliacus anteriorly/inferiorly rotates the right innominate causing the pelvic bowl and lower limb to left rotate. As the lumbar vertebrae are pulled into left rotation and sidebending (non-neutral mechanics), deep core structures such as spinal ligaments, facets, discs and joint capsules are placed under excessive compressive load. In an effort to maintain a smooth cross-patterned gait, the brain is forced to over-recruit the adductors and contralateral external obliques (Anterior Spring System – ASS) to aid in pelvic/torso counter-rotation.

The Lateral Spring System (LSS) is also a problem as shortened adductors tug on the pubic symphysis at one end, and cram the femur and tibia together at the other. The combination of femoral internal rotation and adduction causes the valgus knee to hyperextend. With each step, the medial meniscus cartilage grinds away on the uneven tibial plateau.

During the normal walking cycle, the tibia must slightly internally rotate as the medial arch pronates and springs back up. But in the Figure 2 leg, the tibia is ‘stuck’ in internal rotation which allows excessive weight to travel down through the medial arch creating subtalar eversion, hyperpronation and chaos in the muscles of the Stirrup Spring System (SSS).

As weakened and overstretched tibialis anterior and peroneus longus muscles fail to support and spring the medial arch, antigravity pumping action is lost. With no mechanism available for delivering ground reaction forces back up through lateral leg through the biceps femoris and external hip rotator muscles, the body assumes a labored gait. Typically, any ‘kink’ along the kinetic chain will cause spring system failure. When abductor firing order is disrupted, the quadratus lumborum is recruited to lift the ipsilateral hip allowing the leg to swing through. These people walk like a block and are future candidates for low back surgery unless their myoskeletal imbalance patterns are systematically addressed.

Possible Pain Patterns – At this point, the client may report:

• Low back, sacroiliac or sciatic pain from inflamed facets, discs, and ligaments;

• Trochanteric bursitis or piriformis syndrome due to weak abductors and overstretched gluteus medius;

• Groin pain: femoral nerve entrapment or osteitis pubis (inflammation of the pubic symphysis);

• Adductor tendinopathy at the attachment on the superior pubic ramus;

• Medial knee pain from cartilage degradation or medial collateral ligament strain, and

• Foot and ankle pain from plantar fasciitis, stress fractures, etc.

Muscle imbalances are thought to be caused by abnormal afferent stimuli due to tension, trauma, poor posture, joint blockage, painful or noxious stimuli, excessive physical demands, and habitual movement patterns. Of course, neurologic and genetic factors also play a major role. Some conditions are serious and others are not. Regardless, any dysfunction that interferes with the client’s quality of life must be thoroughly evaluated. Manual therapy in its various forms is still the treatment of choice for correcting many of these strain/pain patterns.