Low Back Pain - Anatomically Short Leg and Contra-Lateral Anterior Hip Rotation
Sighted four times recently, patients suffering low back pain while standing due to anatomical leg length differences between 6mm and 12mm tilting the hips and sacrum, stressing lumbar joints. Also observed in each instance, the hip contra-lateral to the short leg in chronic anterior rotation with pain on palpation of the SIJ. I do not understand the mechanism causing the rotational flop at the hip but speculate it is an unconscious bodily response to correct the postural imbalance caused by different leg lengths. As the hip rotates about the pivot point at the SIJ, the head of the femur moves in an arc posteriorly and superiorly, effectively shortening the longer leg by up to 5mm. Unfortunately, hip rotation can introduce other anomalies due to stress chronic rotation has on the soft tissues of the SIJ.
Where leg length differences are minor, say in the order of 2 or 3mm, this natural coping mechanism may succeed with no undue side effects. However, if the leg length difference equals or exceeds the potential corrective action that can be achieved by hip rotation, the low back pain persists and the resulting SIJ dysfunction causes pain and affects the back line of that lower limb...thickening and tightening of the fascia from the glutes to the bottom of the feet. I have frequently observed symptoms from inactive gluteals, proximal hamstring tendinosis, through to achilles strain or plantar fasciaitis that can result from this phenomenon.
Where these lower limb backline symptoms are sufficiently acute to warrant correction of the anterior hip rotation, sacral tilt will increase and lower back pain while standing will be aggravated. This backward step in the treatment process cannot be avoided if the issues associated with anterior hip rotation must be corrected. However, by inserting thin spacers under the heel in the shoe of the short leg, hip/sacral tilt can be neutralised and lowback pain eliminated.
While this is not rocket science, coverage in my remedial diploma studies was scarce to minimal. More recently the topic was touched on at the Australian Craniofascial Therapy School. Each of the four patients observed have been under the supervision and treatment of higher qualified physical therapists repeatedly over periods of several years but it escaped their attention.
Hip rotation issues I have addressed extensively in earlier articles. Regarding treatment of leg length differences, within reason, if it ain't broke...don't fix it. Where there are symptoms and it has been positively confirmed there is an anatomical leg length difference, start with a heel lift no larger than half the leg length difference or less. Be conservative. Build height incrementally as it takes time for the body to adjust. It may not be necessary to correct for the full anatomical shortfall in leg length. Monitor progress.