Merton L. Root: 1922–2002

On September 25, 2002, the podiatric profession lost one of its most influential members, Dr. Merton L. Root. Dr. Root came to the fore of podiatry through his intense desire to develop a better taxonomy of the various foot types. He entered the profession after a serious study of many medical specialties because he felt that podiatry offered the best opportunities for research. During his student days, he quickly became disenchanted with the subjective methods by which feet were classified and felt that there had to be a better way. The Swedish botanist Carl Linnaeus had a major impact on his development of the idea that a foot taxonomy was possible, and he proceeded to use the osseous skeleton as the basis of such a taxonomy. After graduation in 1952, he entered private practice and pursued an active course of making observations about various foot types and the problems they demonstrated. At that time, there were no generally accepted goniometric methods, so he was left to develop and experiment with various goniometric instruments and techniques. He continued to study the literature on the functional joints of the foot. It was during these first few years of his practice that J. H. Hicks published his first articles about the functional joints of the foot, which would have a major impact on Dr. Root’s thinking. Around 1955, he developed the concept of the subtalar joint neutral position, a totally new idea that would make it possible to establish a baseline for determining whether a foot was pronated or supinated.

Fifty years later, Dr. Root leaves behind only a handful of journal articles and three books. Yet some consider him the father of podiatric biomechanics and would argue that he has had a greater impact on the practice of podiatry than any other podiatrist in the last 50 years. Certainly there have been countless others who have left more writings. However, Dr. Root was the formulator of an entirely new postulate that now forms the basis of a significant part of podiatric practice throughout the world. His concept of a subtalar joint neutral position, deviation from which could be measured as a degree of flatfoot or cavus foot, was contrary to all prior teachings. A careful review of the literature shows that F. J. Cotton and R.W. Lovett put forth a similar idea in 1898; however, their concept did not seem to attract much attention and was not referred to in the literature in the first half of the twentieth century. What Dr. Root offered, though, was not only a definition of neutral, but also a classification of foot types relative to that definition. He taught that feet were not just pronated or supinated but that there was a continuum of abnormal function in either the pronation or supination direction. He also developed various algorithms for treating the problems related to the different foot types both conservatively and surgically.

Those who met him found Dr. Root to be almost indefatigable in his defense of ideas that he considered correct. However, he had enough humility to listen to and consider the opinions of people who disagreed with him. This author personally heard Dr. Root on several occasions express a willingness to adjust his thinking as research and sound deduction proved the value of new ideas. He never intended to be the final authority; rather, he wanted others to continue and improve on what he had started. One example of pushing others to do innovative things was the help his laboratory provided to Dr. Richard Blake in developing the Blake inverted orthotic technique. It has been noted by many that he had a great ability to motivate others to try a little harder to understand the workings of the human foot. Many of those who heard his lectures and studied his writings took on that challenge: Whether they agreed or disagreed with his ideas, all became more interested in understanding.

The Journal wishes to honor Dr. Root’s influence on the podiatric profession and help current and future generations remember his contributions and the attitudes that he tried to foster in encouraging the development of a real science of foot function. The article reprinted here is the first that he published in the Journal. Reading it, one gains not only information about foot function but also insight into the man who had a dream of what the podiatric profession could be. It is hoped that all who read the article will catch the spirit of that dream and carry it forward.

An Approach to Foot Orthopedics

Merton L. Root, DSC, FACFO*

Presented at the APA Annual Meeting, Los Angeles, August 1963.

*Podiatry Staff, Valley West General Hospital, Los Gatos, California; Surgical Staff, California Podiatry College Hospital, San Francisco, California (at time of original publication; now deceased).

Reprinted from JAPA 54(2): 115-118, 1964.

The purpose of this presentation is to acquaint the profession with the type of material the speaker has been presenting at lectures in the Western states. Many requests for the speaker to present this material have been rejected because of inadequate time allowance, and it was requested that this presentation be made so those responsible for seminars would be better able to schedule lecture time when the content of the material is known.

It is not the intent of this paper to present a scientific treatise. The material referred to is too basic and too extensive to be presented in anything less than 40 to 50 lecture hours.

The field of foot orthopedics, and to some degree foot surgery, is a conglomeration of theory, techniques of treatment, and treatment modalities that are too frequently not based upon scientific fact. In most cases treatment procedures in vogue today are only successful in a small number of cases when subjected to the test of time. Also in most cases the prognosis in a given course of treatment is unpredictable so the practitioner is placed in the unadvantageous position of hoping his selected course of treatment is the right one but has little other than intuition and experience upon which to base his decision.

The ultimate objective of research in any medical specialty is the achievement of a specific definitive treatment for a diagnosed condition or disease. First, the disease or condition must be isolated and studied as to its etiology and symptom complex. With this information a method of differential diagnosis and specific treatment can then be devised.

In foot problems the reverse has been true. The symptom of a disease or condition has been accepted as an entity in itself and treatment has been based upon an attempt to eradicate the symptom without consideration of the cause of the symptom. As an example, it soon becomes obvious to the podiatrist that all hallux valgus deformities are not the same and yet he continues to treat hallux valgus as an entity in itself rather than search for the cause of hallux valgus so that the cause itself might be eliminated.

The fault appears to lie not in the lack of interest but in the confusion created by a highly complex and variable organ. In podiatry today the diagnostician has little upon which to base a study of a particular foot problem.

It behooves the podiatry profession to first of all establish a common nomenclature which is specific in its meaning so that knowledge can be accurately transmitted. Secondly, the foot must be classified as to its various functional and structural types, with specific clinical methods for measurement and evaluation so that one foot type at a time can be given detailed study to further our knowledge of the problems we face. With this intention the speaker has attempted to classify feet using morphology as the basis of a classification. The osseous structure was selected as the basis of classification because it most readily lends itself to measurement and can be seen radiographically. The shape of bone structure not only affects the gross appearance of a foot, but primarily determines the type, degree, and direction of motion of the various functional joints and determines the function of muscles acting to produce motion and stability within the foot.

As this classification began to develop it soon became obvious that there were many deformed feet that had normal morphological structure but had been subjected to extrinsic forces that created a malalignment of osseous structure thus altering function to create pathology. It became necessary to study the morphology of the entire lower extremity to understand the pathological changes seen in feet.

To this point the speaker has formed the following conclusions:

The individual may be born with a normal foot of which there are two types morphologically but both exhibit identical function. Other individuals are born with a defect of morphological origin that alters the function of the midtarsal, subtalar, or ankle joints. Any one or all of these joints may be involved in one individual. Each joint involvement presents a certain specific morphological picture radiographically and a specific alteration clinically on measurement. Each involvement alters function of the foot in a definite specific manner and each produces its own specific symptom pattern. In addition, the foot itself may attempt to compensate for a joint defect by either pronation or supination in the subtalar joint which then produces structural malalignment and abnormal function of the entire foot and ultimately affects the entire posture of the individual.

In addition to foot problems in which the etiology lies within the foot itself there are compensatory pronated and supinated feet that result from abnormal structural development of the tibia, femur, or hips. These defects constitute torsion on the transverse plane and curvatures and angular deviations on the sagittal or frontal planes that affect the position of the talus in its relationship with the rest of the foot.

In effect this study has exposed the speaker to an insight into the complexity of the etiology of foot problems. It has also revealed a very constant logical explanation for the variable symptomatic pattern seen. Most important it has pointed up the need for thorough postural examination of the lower extremity which then dictates the treatment approach and the results of this treatment are prognosible to an extent not previously possible with less scientific approaches.

Briefly, the foot defects which have been classified on a morphological basis are as follows:

The midtarsal joint may exhibit a varus or valgus deformity. In other words, when the sagittal plane of the rearfoot is vertical, the plantar surface of the forefoot is tilted toward (varus) or away from (valgus) the midline of the body. In the rigid body type, the foot remains fixed in this position. Hyperkeratosis, soft tissue and osseous changes become evident very early in life in the region of the 5th metatarsophalangeal joint in the varus and 1st metatarsophalangeal joint in the valgus forefoot condition.

The subtalar joint is also affected by varus or valgus deformity. In this case the entire plantar surface of the foot is tilted toward (varus) or away from (valgus) the midline of the body. The subtalar varus foot is one that is subjected to traumatic soft tissue and osseous changes along the entire lateral border while the subtalar valgus is a relatively asymptomatic flat foot which appears to be much worse than it actually is from a functional standpoint. The subtalar varus and valgus deformities are of congenital origin. The subtalar joint also may be affected by acquired deformity which is totally different. These defects may be either acquired supination or pronation and affect the position of the entire foot. In acquired supination, the foot functions in a fixed position of inversion, adduction, and plantar flexion. In acquired pronation the foot is in a fixed position of eversion, abduction, and dorsiflexion.

The ankle joint may be involved with an equinus or calcaneus defect of congenital or acquired origin.

All of the foot defects referred to tend to alter the position of all or part of the plantar surface of the foot so that full contact is not made with the transverse plane of the supporting surface. In feet with minimal joint motion, the foot remains in this position and trauma occurs as a result of excessive weight bearing in the portion of the foot making contact with the supporting surface.

Most often, however, there is sufficient motion present in the subtalar joint so that pronation or supination will occur in this joint in a compensatory attempt to bring the entire plantar surface of the foot into contact with the supporting surface. Since the axis of motion of the subtalar joint is such that any motion occurring in this joint occurs on all three body planes it tends to correct a one plane defect by a three plane change and in so doing produces deformity on two other planes. This change results in a malalignment of osseous structure of the entire foot and a stance phase muscular imbalance that produces hypermobility and resultant symptomatology in the foot that is much greater than the symptomatology which would have been present had the original defect not been compensated by subtalar pronation or supination.

Although time does not allow a full discussion, it must be stated that these foot defects mentioned probably constitute the etiological factor in less than half of the cases of foot deformity seen in the podiatrist’s office. The etiological factor in these other cases is extrinsic and consists of congenital or acquired developmental variations in some part of the entire lower extremity, pelvic or back region. The following conditions have been isolated in given cases as the etiological factor in compensatory subtalar foot deformity. On the transverse plane there is tibial or femoral torsion, anteversion or retroversion at the hip, and lordosis of the spine. On the sagittal plane, excessive anterior curvature of the tibia or femur, genu recurvatum, and a short limb. On the frontal plane there is excessive lateral curvature of the tibia or femur, genu varum or valgum, coxa varum or valgum, a short limb or scoliosis of the spine.

These postural deformities result in an alteration in the positional relationship between the talus and calcaneus that is manifested in either subtalar pronation or supination depending upon the direction of the force exerted from above upon the foot.

It should be kept in mind that with the minor exception of flexion and extension at the ankle joint, the talus is functionally a part of the leg and follows the tibia thus its relationship with the rest of the foot is almost entirely dependent upon the osseous structure above. Any force from above producing a twist or tilt of the talus produces subtalar and midtarsal joint motion and alteration in the entire function of the foot.

A justifiable question at this point would be “Of what value is all this information to the average podiatrist?” This question has been asked of me many times and I can only answer it this way. Nearly every symptom of a mechanical nature you see in your office emanates from the conditions I have mentioned. The callus, corn, bunion, hammer toe, hallux valgus, neuroma, heel spur, retrocalcaneal bursa, apophysitis, ligament strain, fatigue—all of these and many more have their etiology in the postural and foot defects briefly referred to. By isolating and understanding the underlying etiological defect the podiatrist is better able to select or devise the most direct and specific treatment that will not just eliminate the immediate symptom but also prevent the future formation of more disabling symptomatology. Unfortunately, and all too often, treatment devised to relieve the pain of a specific symptom does just that, but it also increases the malfunction of the foot and sometimes the entire lower extremity, and ultimately can produce a greater symptomatic pattern than that for which the treatment was devised. Knowledge of the basic etiological factors present in a given case accompanied by a thorough understanding of the pathomechanical changes leading to the development of a symptom eliminates the possibility of choosing a course of treatment that further disrupts function.

It has been the experience of the speaker that all feet cannot be treated mechanically because some problems are intractible and treatment increases the malfunction. In the case of the compensated talipes equinus foot type which produces the most severe symptoms of all foot types, not one case in the speaker’s experience ever benefited from appliance therapy even though temporary relief of pain could be accomplished in most adult cases. Over a period of two to five years of treatment all cases became more symptomatic and function of the entire lower extremity was further disrupted. However, in every case in which the heel cord has first been lengthened there has been remarkable improvement of function from appliance therapy and relief of painful symptoms is almost immediate. After up to six years of observation these cases are all showing evidence of gradual improvement of function with no further adverse symptoms developing. In those cases in which children were treated with appliances for this foot condition without benefit of surgical lengthening of the heel cord first, none showed improvement, most became worse, and in two cases the treatment produced a severe hypermobility of the knee joint manifested by a genu recurvatum. Also in this foot type which exhibits severe symptoms of hypermobility in the forefoot such as hallux valgus, hammer toes, dispersive plantar callosity, etc., surgery performed for these conditions while giving temporary relief, enhances the malfunction of the forefoot to provide nearly disastrous results which are only made worse by further local surgery.

In addition to the obvious immediate benefits of basing treatment upon knowledge of foot function, the greatest benefits will accrue to both the public and the podiatry profession as each individual foot type is studied by many students and practitioners with the intention of improving upon present techniques of treatment and devising new corrective procedures for those conditions which are now intractable. With the techniques for measuring defects that have been devised to date we are able to adequately follow the progress of treatment for a specific condition and know whether that treatment is effective and to what degree it is effective.

In all probability the most important advantage to basic research and study of foot function and malfunction is that only in this manner can the existence of podiatry as a distinct medical specialty be reconciled by other medical groups. Podiatry must contribute to medical literature basic knowledge upon which to build a regime of treatment rather than remain a parasitic profession dependent entirely upon other medical fields for the advent of knowledge upon which to improve treatment techniques.

In the speaker’s opinion, only undisputable evidence that the podiatrist has the most comprehensive understanding of the function of the lower extremity will achieve full recognition by the public and medical profession that the podiatrist is the specialist of the foot.