Skip to content

Leg-length and Cycling: Dr. Bryce Crowley

Upper Cervical Adjustment:
A different approach to leg-length discrepancies


H140 club pic

Very few people generate the same pedaling power with both legs. For some, the difference is dramatic, particularly if there is a measurable difference in the length of a rider’s legs. We have noted, for example, that 1984 Olympic road race gold medallist Alexi Grewal suffers from a significant leg-length discrepancy due to an injury during his teens. Prior articles we have run on correcting leg length discrepancies using cleat shims, position adjustments and/or special cranks and pedals (VeloNews, May 8,1995 and VeloNews, March 1993) triggered a steady stream of correspondence.

No one disputes that there are thousands of people walking around with leg-length differences of more than half-an-inch. The controversy usually focuses on how the discrepancy was caused and how best to deal with it. One school of thought believes that it is natural and predictable for a significant proportion of the population to have leg bones of different lengths. Thus, shoes and other sports equipment should be corrected to accommodate it. Others argue that a structure as precise as the human body, whose operation depends upon exact and repeatable reactions occurring on the scale of milliseconds, would not produce bone length discrepancies as large as half-an-inch or more, except in cases like Grewal’s, where an injury was involved. They argue that corrections should be performed on the body and not the equipment.


Misaligned (or “subluxated’) vertebrae can impinge on the nerves and hamper body function. Chiropractors apply force to parts of the spine with the intent of returning vertebrae to their normal positions. Forceful cracking sounds usually accompany the adjustment. The Upper Cervical Spinal Correction is distinct in that the adjustment is only performed on the Cl vertebra. Furthermore, the direction of the application of force to perform the adjustment is not based simply on palpation (the chiropractors “feel”) but rather on detailed analysis of posture. From the posture analysis, a three-dimensional force vector is calculated and then applied to Cl to correct body position.

Accidents and injuries tear loose the connective tissues that support a balanced body posture, head to toe.  This distortion is easily measured.  The pelvis measures un-level during a supine leg check. One leg measures shorter than the other.  As a counter-balance mechanism the skull and the other vertebrae rotate and tip to compensate for rotation and instability in the pelvis. The head weighs between 8 and 14 pounds. If it is not sitting straight on top of the spine, the muscles of the body must do something to counteract this bowling ball hanging off to the side. If the muscles on one side of the spine are tighter than those on the other, then the pelvis is pulled up on that side, thus “shortening” that leg and you suffer from reduced power output in your pedal stroke.  In addition, body position on the bike is compromised.

Diagnostic Methods

The QSM3 Upper Cervical Progressive Doctor uses a complex postural analysis to quantify body distortion. Vertical pelvic tilt, leg length inequality,  pelvic rotation in a horizontal plane, the twist of the spinal column at the shoulder level, and the amount of weight the patient carries on each foot.

Patients first lie flat on a table, in a very specific fashion, to have leg length differences measured.  Then a standing postural analysis is conducted.  Body weight balance is measured on each foot.  Body weight distribution of 3lbs differential is optimal.  Measurement for twist in the pelvis, lean of the upper back from vertical, twist of the torso, shoulders being level and tilt of the head are each documented.  Muscle tension in the neck is tested.

Adjustment procedure

The Doctor applies an extremely light force directly along the determined vector direction to return the body to its proper position. The force must be applied with enough pressure to decompress the resistance to the adjustment caused by the body/posture injury.

The patient lies on his or her side on a low inclined bed with a head support. The adjustment is performed with the side of the heel of one hand on a corner of the Cl vertebra located just behind the patients ear lobe.  The Doctor takes a number of measurements to determine where to stand and how to orient his body relative to the patient.  A different corrective position is used with each aspect to re-balance the patient.

Patient’s say that they only feel a slight touch near their earlobe.  The slight warmth of the doctor’s hand against their neck without any deflection of their neck, head or body during the procedure.  When the correction is complete the body has relaxed, returned to balance and the posture is re-tested.   Afterward, the leg length will be even, and the muscles will begin the process of recovery.

Patients’ comments

The patients report feeling immediate improvement in body balance and ranges of motion. The reduced strain in the body posture is immediate.

Patients’ comment that while many joke about “having magic words said over them… ”  a reduction in the symptoms of body aches, but better body posture is amazing in addition to generally improved overall health.

Dr. Crowley has observed that his method is simply the application of physics to the human body. The adjustments can hold for years, unlike most chiropractic adjustments. After the initial series of treatments, visits are separated by months, and he says if alignment is not off, “we don’t touch ‘em”.


The practice of chiropractic was established in 1895 by D. D. Palmer, who founded the Palmer College of Chiropractic in Davenport, Iowa. In the 1940s, the late John F. Grostic, D.C. and Ralph Gregory, D.C. developed the Grostic Technique of adjusting the atlas vertebra. The current upper cervical technique is an outgrowth of that approach. 

When asked why less than 1 percent of chiropractors specialize in this technique, observation says that chiropractors are pulled in many different directions toward various chiropractic specialties, and, t is easier to crack backs than to be good at correcting posture.”

John Dunn, D.C., a cyclist, and NUCCA chiropractor from Tallahassee, Florida, says that it takes a certain type of person to practice the technique. It is an exacting method and a real-life application of vector analysis, and therefore, attracts “the pocket-protractor types who drive used cars.”  He notes that the work-up is time consuming, the adjustment is sublime, and the follow-up visits are less frequent so there isn’t much motivation for a chiropractor to pursue the approach.

“It also takes a lot of nerve to tickle someone behind the ear and tell them they are going to be just fine,” joked Dunn.

Are your legs balanced?  Is your body in the proper alignment to harness all of your potential strength for optimal cycling performance?

HURRY, call now to schedule your complimentary posture evaluation to determine balanced power output through an equal leg length.

Davis County Spinal Care | (801) 888-9906