Bridges Between Whole-Body Dysfunctions and the Feet: A Close Examination
By Scott Cuthbert, DC
Many think of the sacrum as the foundation of the spine, but as Gillet and Liekens1 point out, the ischia are the base when sitting and the feet when standing. Many in the chiropractic profession's history have emphasized the foot's role in spinal function.2-6
As the foot pronates, the talus rotates, carrying the tibia into medial rotation that extends up to the femur, moving the greater trochanter anteriorly and laterally, and stretching the piriformis by a windlass mechanism. Because of improper piriformis support, a subluxation of the sacrum may result in an anterior and inferior position. To compensate, the gluteus maximus muscle contracts to resist the forward and downward disposition of the pelvis.
Secondary to gluteus maximus contraction, the innominates become subluxated. As a result of the sacral anterior inferior subluxation, the 5th lumbar is "mobile" and, according to Lovett's Law, will gravitate and rotate toward that side; thus the beginning of structural scoliosis is established.
The above is a synoptic review of a description originally presented by Janse in the May 1954, issue of the National Chiropractic Association Journal.7 Other early descriptions of spinal problems resulting from the feet include hyperlordosis8 and sciatica.4
Foot Function and the Spine
The importance of foot function on the spinal column is shown in a study (n=72) by Ceffa, et al.,9 in Italy. The feet and spine were studied with thermography on individuals who complained of back pain and were under chiropractic care. Twelve patients had flatfeet, 41 "hollow" feet and 47 load alterations revealed by thermography. The study was instituted because of "significant reoccurrence, after a successful manipulative treatment, of muscular pains and defense contractures, in the same area or in other segments of the spine."
The patients were treated with orthotics, and examined several times and at various time intervals. The imbalanced thermographic patterns in the lumbar and thoracic regions were balanced or greatly improved, as was the thermographic pattern of the feet. Comparison of the subjective and objective results of this study showed 21 patients pain-free with normalized thermographic pictures; 34 had been pain-free over one year, with significant improvement in the thermographic pictures; 14 had less frequent and less severe pain with improved thermographic pictures; and three had no improvement, with no improvement of the thermographic pictures.
In 1954, Janse7 summarized the body's structural integration and the mid-20th-century chiropractic conceptual approach by stating, "[F]aulty body mechanics is usually a consequence of a serial distortion rather than a single local lesion. We mean, thereby, that the problem of postural and mechanical pathology is the result of distortions that may begin in the foot or feet, extend up into the leg or legs, then into the knee or knees. From there, it may ascend into the hips and sacroiliacs, reflecting onto the vulnerable lumbosacral articulations and eventually the spine to the occiput."
In 1967, Goodheart4 associated psoas muscle dysfunction and sciatic neuralgia with excessive foot pronation. He demonstrated the immediate effects of improving body function and reducing pain by eliminating adverse stimulation to the foot proprioceptors by simply having the patient stand on the lateral borders of their feet to take the strain off the medial longitudinal arch. This can easily be demonstrated when some muscles test weak when standing, but are strong when the patient is supine or prone. The muscles will immediately test strong when the patient stands on the foot's lateral border, and weaken with usual weight-bearing.
Foot dysfunction is not the only reason muscles may become weak when standing, but it is the most frequent cause.2 Monte Greenawalt, founder of the orthotics company Foot Levelers, quoted Goodheart's research on the feet regularly in his books and published research papers.3,5
An individual who has suffered a hyperextension / hyperflexion cervical sprain / strain, or the so-called "whiplash" accident, may have their condition complicated by foot dysfunctions. This, of course, is probably not part of the original traumatic condition; however, it can be a perpetuating factor of the cervical problem. This results from the role the foot proprioceptors play during walking on the facilitation and inhibition of the head rotating muscles, such as the sternocleidomastoid.10
Because of this disorganization, the insertion of these muscles at the mastoid processes may be exquisitely tender. Travell and Simons11 have noted that myofascial trigger points from as far away as the posterior tibialis muscle can refer pain and muscular dysfunction into the temporomandibular region.
The manual muscle test permits a specific challenge to a joint in the foot to be immediately followed by another specific test to a distant muscle, thereby making evident to both the physician and the patient the dynamic interactions going on between two distant structures. Chiropractic diagnostic methods have made the connection between foot dysfunctions and whole-body dysfunctions measurable.2 The visual diagnosis of a specific joint or muscle impairment in the foot and simultaneously its relationship to a specific joint or muscle impairment in the hip, shoulder, neck or jaw is difficult.12
Because of the intricate connections in the neuromuscular system, a change in any part of the body can disturb function elsewhere in a distant part. An example of this is that an anterior cruciate ligament injury has been shown to generate changes in the posterior cervical, upper and lower trapezius, sternocleidomastoid, anterior temporalis and masseter muscles.13
There is no easy way to visually assess the specific muscle impairments seen in the neck after a knee injury, but the use of the chiropractic "sensorimotor challenge" test to the knee, followed immediately by specific manual muscle tests to the neck, can make these specific cervical muscle impairments produced by an anterior cruciate ligament injury evident to the examiner and patient.2, 14-18
Another area that might be influenced by foot dysfunction is the stomatognathic / craniomandibular system.19 Cranial dysfunctions can be created or perpetuated by disorganized function of the sternocleidomastoid muscles as they pull on the mastoid processes during gait.20-21 This is a primary cause of neurologic disorganization because of the stomatognathic system's close integration with the equilibrium proprioceptors.
Richie22 notes that balance and postural control of the ankle appear to be diminished after a lateral ankle sprain. This can be restored through treatment and is mediated through central nervous system mechanisms. One might question whether the inflexibility of the foot or the improper stimulation of the foot proprioceptors contributes more to nervous system's inability to maintain proper orientation in space.
Unilateral hyperpronation and the resultant "short leg" causing pelvic obliquity have been mentioned as factors in scoliosis development.7, 23-24 Possibly a greater contribution to the problem is the foot–related neurologic disorganization found by chiropractic examination. A major component of almost every idiopathic scoliosis case is neurologic disorganization.
Dananberg has shown that symptoms associated with foot dysfunction include low back pain, tibialis posterior dysfunction and anterior knee pain.25 Dananberg and others have also shown that functional hallux limitus2 to be a remote, often-hidden source of postural degeneration and pain. Functional hallux limitus involves limitation in dorsiflexion of the 1st metatarsal-phalangeal joint during walking, despite normal function of this joint when non-weight-bearing. Mattson, Ferrari and Dananberg have each shown that improvements in foot function, mobility and strength resulted in marked improvements for patients with chronic nonspecific low back pain.26-28
The work of Gracovetsky29 (the spinal engine theory), developed in the mid-1980s (and published in 1989 in his book of the same name), proposes that the spine optimizes its efficiency of motion in the gravitational field by using the spine to propel the legs forward, capturing the ground reaction force to decouple the spinal segments with each step of the gait cycle. Storing the ground=reaction force as a potential energy in the viscoelastic tissues of the lower extremity and spine (similar to the Hicks windlass mechanism,2 which stores elastic energy through the plantar fascia during the swing phase of gait), and then expressing that potential energy as kinetic energy as the spine propels forward. Disturbances in the feet may alter the ground-reaction force described by Gracovetsky and thereby impair the force transmission potentials of the spinal engine through the rest of the body.29
Spinal Dysfunction and the Feet
In addition to foot dysfunction adversely affecting spinal function, the converse is applicable. Interplay between the spine and feet are demonstrated by Gillet and Liekens.1 They examined the spine, but made no corrections to it; only foot corrections were made. "In 86% of the cases, there were varying changes (small to important) in the spine ... either immediately or slowly." In another portion of the study, the height of the arch was periodically measured while spinal corrections were administered. "In 37% of these cases, there was definite change in the feet as the spinal fixations were eliminated."
In chiropractic practice, most foot correction is for chronic problems. When acute trauma is present, one must not only provide the proper type of treatment for the local injury, but also be aware of remote conditions that might develop. The effects of trauma to the foot may cause the afferent nerve supply to cause disorganization, adversely affecting remote areas, as well as the problems that develop with disuse during rehabilitation.
Nicholas and Marino30 state, "the more distal the injury site, the greater the total weakness of the affected limb. Thus, distal injuries produce more weakness to the entire limb than do proximal ones." When foot and ankle trauma causes continued problems, there is significant weakness of the hip adductors and abductors as compared to the uninvolved contralateral side.31
Rothbart and Estabrook32 found a high correlation between excessive pronation, static pelvic abnormalities and chondromalacia patellae, with 96 percent of the patients (n=97) in their study showing excessive pronation and low back pain. Treatment was based on a combination of chiropractic and podiatric therapy, with a six-month follow-up. Analysis of the success in this tandem approach was promising.
Rothbart and Estabrook offer a whole-body model suggesting that asymmetrical pronation patterns (one arch dropping more than the other) initiates a forward and downward rotation within the sacroiliac joint. Entrapment of the sciatic nerve then occurs between the piriformis muscle and sacrospinous ligament. They suggest that paresis is then observed clinically, with weakness, numbness and eventually paralysis of the affected limb.
They also propose a model for chondromalacia, explaining the pathomechanical events associated with oblique tracking patellar syndrome. They suggest that excessive pronation is the causative factor directing asynchronous rotation between the shin and femur. This forces the patella out of its normal tracking groove, which in turn generates erosion between the inferior margin of the patella and femoral epicondyles.
In patients with symptomatic and asymptomatic patellar pain, assessment for muscle strength impairments may be essential to restoring the normal "track" or "path" of the patella through any particular movement. Any aberrations in the recruitment or coordination of these sequential movements of the patella (generated by the muscles crossing the knee) will be signaled to the central nervous system. In patients with knee or patella pain, the CNS will seek to inhibit this inappropriate movement by weakness, stiffness or pain.33 This reorganization of movement control is a protective strategy which serves to alleviate some of the stresses imposed on the damaged tissues of the knee.