Leg-length inequality and the body’s proprioceptive system

There is a connection between leg-length inequality (LLI) and the proper functioning of the body’s proprioceptive system.

Restoring leg-length balance through the use of custom-made stabilizing orthotics and/or lifts can improve the proprioceptive sensory organs’ ability to coordinate body movements, postural alignment and balance.

Step one: LLI

Differences in leg lengths can be either structural or functional in nature. Structural LLI is due to anatomical causes, such as unequal growth rates, fractures, lesions and degeneration.

Far more common is functional LLI, which results from physiological responses secondary to biomechanical stresses along the kinetic chain.

The most common cause of functional LLI is excessive pronation, a rolling-in of the foot that produces an apparent shortening of the limb (Fig. 1). When a patient is standing, a difference in leg length results in an uneven foundation for the pelvis, causing various postural shifts in response (Fig. 2). Eventually, specific degenerative changes will be seen in the hip joints, pelvis and spine.^1-3

During gait, the foot/ankle complex will overpronate, causing excessive inward (medial) rotation of the entire lower extremity.

The increased rotational forces are transmitted up the leg into the pelvis, especially the sacroiliac (SI) joint.⁴ Clinical research confirms correlation of pain and LLI in nearly 80 to 90 percent of patients studied.⁵ Presenting symptoms may include chronic or recurrent sciatic pain, unilateral hip symptoms and pain in the lower back or along the thigh.^1,6

The structural misalignment typical of prolonged LLI affects muscular pull and the amount of weight borne by the joints. When weight and pull fall abnormally on the musculoskeletal system, serious and often subtle consequences eventually occur. The body’s adaptation resources become exhausted, endurance is reduced and strain on the body increases.⁷

A vicious cycle of misalignment, muscle fatigue and ligament stress is created.

Step two: Proprioception

Proprioception is a person’s sense of the motion and position of the body.⁸ And the body is equipped with several interrelated mechanisms that provide this vital information.

Specialized nerve endings are present in the soft tissues of the musculoskeletal system that interact with the central nervous system and coordinate the body’s movements, postural alignment and balance. The muscular system is the largest system in the body, and it is responsible for maintaining postural alignment and moving body segments. The most important sensory nerve endings for controlling this massive system are the muscle spindle fibers.⁹

Specialized nerve sensors are found throughout the musculoskeletal system, in all skeletal muscles and in every ligament, joint capsule and articular connective tissue. The three areas of greatest proprioceptive importance are: the foot, the spine (generally), and specifically, the upper cervical spine (Fig. 3).⁹

Step three: The LLI/proprioception connection

The foot is one of the greatest sources of proprioceptive input. LLI commonly arises from misalignments (excessive pronation) in the feet. LLI affects muscular pull, which leads to muscle fatigue and ligament stress. Muscles and ligaments are the source of a large number of the body’s nerve endings and proprioceptive sensors. When muscles and ligaments are under continual strain, the body’s ability to maintain proper proprioception is negatively affected.

What can be done?

Effective clinical management of LLI depends on the type of leg length inequality (functional or structural), the degree of inequality and the age of the patient.

Foot Levelers custom-made stabilizing orthotics (Fig.4) shown below are valuable for most LLI cases (see Table 1). Another helpful adjunct is Foot Levelers Thera-Ciser, especially the series of ankle exercises.

Joint manipulation, especially of the spinal joints, has a direct effect in normalizing receptor responses.^10-12 Patients with proprioceptive imbalances benefit from various external supports to help them achieve proper body positioning. These include stabilizers for the foot and ankle, cervical support pillows for chronic neck pain and chair supports to provide alignment of the back during sitting.

Custom-made, flexible stabilizing orthotics can make an immediate impact on leg length inequality and the body’s proprioceptive functioning by improving postural alignment (Fig. 5). Your adjustments, along with Foot Levelers orthotics, are the winning combination in treating both imbalance and LLI.

Download your free Top 5 Reasons to Get Stabilizing Orthotics poster here

 

References

1. Friberg O. Clinical symptoms and biomechanics of lumbar spine and hip joint in leg length inequality. Spine. 1983;8(6):643-651.
2. Friberg O. The statics of postural pelvic tilt scoliosis; a radiographic study of 288 consecutive chronic LBP patients. Clin Biomech. 1987;2:212-219.
3. Giles LGF, Taylor JR. Lumbar spine structural changes associated with leg length inequality. Spine. 1982;7(2):159-162.
4. Botte RR. An interpretation of the pronation syndrome and foot types of patients with low back pain. JAPA. 1981;71:243-253.
5. Yochum TR, Barry MS, Austin WM. The short leg (revised edition). Practical Res Studies. 1994 [rev. 2003];4(5):1.
6. Hlavac HF. (1977). The Foot Book Advice for Athletes. Mountain View, CA: World Publications.
7. Schafer RC. (1982). Chiropractic Management of Sports and Recreational Injuries. Baltimore: Williams & Wilkins.
8. Gatterman MI, ed. (1990). Chiropractic Management of Spine-Related Disorders. Baltimore: Williams & Wilkins: 413.
9. Hyland JK. Proprioception: alignment and movement. Practical Res Studies. 1997;7(2):1.
10. Slosberg M. Effects of altered afferent articular input on sensation, proprioception, muscle tone and sympathetic reflex responses. J Manipulative Physiol Ther. 1988 Oct;11(5):400-8.
11. Rogers RG. The effects of spinal manipulation on cervical kinesthesia in patients with chronic neck pain: a pilot study. J Manipulative Physiol Ther. 1997 Feb;20(2):80-5.
12. Fitz-Ritson D. Assessment of cervicogenic vertigo. J Manipulative Physiol Ther. 1991;14(3):193-198.