Back Injuries — Part I

Kendo Clinic articles are intended as an educational forum only. The articles presented offer only a limited over-view of the great number of possible ailments and their variations. Articles are based on documented medical practices; use established terminology and are intended to provide the reader with the information needed to engage in consultation with medical professionals. The authors of Kendo Clinic and the editors of Kendo World stress that the information offered in these articles should under no circumstances be used for self-diagnosis or self-treatment. Persons suffering from any injuries or ailments are urged to seek the advice of licensed medical professionals at the earliest opportunity.




The importance of the spine as mechanical center of body movements, the conduit for the nervous and motor systems as they branch throughout the body, its complex construction and system of bones, connective tissues, muscles, and nerves, make the study and understanding of the lower back a difficult subject.  Add to this the dynamic and varied physical activity we engage in kendo practice, the tremendous loads we place upon the lower back, and we can begin to understand the complex nature of understanding lower back pain. Such being the case, I have tried to strike a balance at keeping explanations simple enough for the common reader; however, it has been necessary to include many terms and concepts, if only for the most fundamental explanations. The issues of lower back pain, prevention, and care, are important for every kendo man and woman. I hope readers will bear with me as we engage this lengthy subject.

Lower back pain occurring in kendo practitioners can be found at all levels, age groups, and rank divisions. Lower back pain can be a persistent problem, disabling the kendo man or woman from maintaining optimal posture, accomplishing correct execution of techniques, and diminishing their ability to conduct the activities of daily life free of discomfort.

In this first article I will introduce lower back anatomy and physiology, and overview classification of the sources of lower back pain. In the second part, we will examine specific injuries in kendo practitioners, and the diagnosis, treatment, and physical therapy and rehabilitation of those ailments. Equipped with this knowledge, we will then discuss preventative measures and exercises for the avoidance of lower back pain.

In the adult, the spinal column is a flexible, curved, co-axial arrangement of twenty-six bones, 24 of which are generally termed vertebrae. The segments appear to be partially interlocking, stacked one atop another in a ladder-like arrangement, extending down from the base of the skull to its lowest members, the sacrum and coccyx.

The vertebrae are identified as to their region. In principle, the groups are from the base of the head, or skull, down: the cervical spine (C1-C7,) thoracic spine (T1-T12,) and the lumbar spine (L1-L5,) sacrum, and coccyx.

The vertebrae have three functional aspects, the  vertebral body, with broad oval surfaces providing for compressive weight-bearing capability, the neural arch, a complex structure for passage and protection of nerves, and the bony processes, projections of bone that provide for muscle attachment.

At the bottom of the functional vertebrae are the sacrum and the coccyx. The sacrum, a triangular formation, situates between, and functions integrally with, the two halves of the pelvic group, the bilateral structure branching to the two legs.  Attached to the bottom end of the sacrum, the coccyx, a non-functioning member, forms a triangular point.

With concern to lower back pain in particular, we will focus our attention on the five vertebrae of the lumbar spine, L1 to L5, the sacrum, and pelvis, all collectively know as the lumbopelvic region.

In the spaces between the vertebrae, a composite pad-like structure, or intervertebral disc, separates the vertebrae, providing for both connection of the vertebrae, one to another, and for the pivot-like movement of the vertebrae relative to each other. Embedded in the upper and lower weight-bearing surfaces of each vertebra is a soft, oval pad, or hyaline cartilage, generally known as chondral cartilage. The chondral cartilage is encircled by another tough border of cartilage known as the epiphysial ring. Normal chondral tissue is smooth and wear resistant, and combined with joint fluid issuing from a grass-like membrane within the joint, synovial fluid and synovium respectively, an exceptionally low coefficient of friction.

lumbar spine



Contained within a membranous covering enclosing each joint, or joint capsule, these cartilage surfaces normally remain in high state of fluid saturation, or hydration. The alternating forces of compression and decompression serve to push the nourishing and lubricating synovial fluid in and out of the porous tissue.

Fibrous tissues spanning the gap between two vertebrae connect the hyaline cartilage and epiphysial ring of one vertebra to another. At the functional center of these structures is an incompressible gelatinous ball, or the nucleus pulposus, which rides on the chondral surfaces. It is upon this nucleus pulposus that adjacent vertebrae pivot upon each other.

Supplementing these structures are tough cartilage connective tissues, on the forward, or anterior side, are the sturdy anterior longitudinal ligaments, and on the rearward, or posterior side, by the weaker posterior longitudinal ligaments. These ligaments span between upper and lower vertebrae to provide the basic form of the spine.

The spinal column also serves as the main conduit for the nervous system. The multi-branched system of nerves, or spinal cord and nerve root, issue forth from the base of the brain, and travel down through the spine. Signals for body position, body movements, tactile senses, pain, heat and cold, and even involuntary activities such as organ function are transmitted through this nerve network.

Posterior to the main vertebral body, the spinal cord and nerve roots descend down from the brain, through a tunnel formed by an opening in each vertebra, or the vertebral canal. Smaller groups of nerves, or rootlets, separate, passing from the vertebral canal, penetrate laterally through narrow intervertebral notches, and past the connective tissues and muscles.

Stabilized and articulated by muscles and connective tissues, permeated throughout by the body’s central nerve network, the spinal column serves as the main structural and neural component from which most all body motions, ambulation, and senses are made possible.

Physiologically, the nature of the spinal column, related tissues and nerves, change with age. In the young, when growth hormone output is highest, cell turnover and regeneration are occurring at a fast rate, bones are thin and are susceptible to stress induced fracturing. Around the time of puberty, bone mass has increased, reducing the vulnerability to fracturing, but the reduction of growth hormone production marks the beginning of the slow but inevitable process of aging, deterioration of bone and soft tissues, and dehydration of intervertebral discs that lead to susceptibility to other ailments.

Joint diseases such as osteoarthritis, result in changes that usually progress with age. Arthritis degrades tissues and is a source of pain in itself.  Degenerative changes affect the mechanical properties of tissues and their ability to work efficiently in conjunction with each other.  Arthritic conditions may also serve to exacerbate other lower back problems directly resulting from activity, including kendo activity. Osteoarthritis is not uncommon in older kendo practitioners, the cumulative result of overworking the joints, over the many years.

Metabolic changes that occur with age result in the body’s diminishing replacement of calcium in the bony masses. Of recent notoriety, osteoporosis is a condition in which bones become brittle, and eventually diminish in size.  This condition is usually associated with women; however, it is occurring in men as well. Changes in body proportions alter the mechanics of each person’s posture, body movements, and response to loads. The effect is overall, but is significant with particular regard to the spine and lower back, and therefore warrants mention.

According to two key authorities on the subject, McCulloch and Tensfeldt, classification of low back pain can separated into five different groups.

1. Spondylogenic Back Pain:  This pain is associated to the spinal column and its related structures. Pain may be symptomatic of lesions to the bony structures and joints, including the intervertebral discs, ligaments, and muscles.

2. Neurogenic Back Pain:  Tension, irritation, or compression of nerve root or roots are the most common causes of neurogenic pain

3. Viscerogenic Back Pain:  Disorders of the kidneys, other large interior organs, or viscera, of the lower abdominal cavity may result in lower back pain.

4. Vascular Back Pain:  Defects in the circulation system in which blood vessels, arteries and veins, are abnormally increases in size, or dilated. This type of problem may occur in the form of pathological processes in the tissues of the lumbopelvic region, or in tissues adjacent to this area.

5. Psychogenic Back Pain:  In mild instances psychosomatic pain, ranging to mental illness, psychological stresses from depression to emotional breakdown, may result in a patient presenting with back pain.

Quite often, lower back pain is associated with a single trauma relating to one episode of improper lifting or upper body exertion. While these cases do exist, in kendo, the overwhelming majority of cases are related to overuse and fatigue. An injury with severe symptoms is considered acute. An ongoing, reoccurring ailment is termed chronic. A severe episode of a chronic ailment may be termed an acute phase of a chronic condition.

Due to the complex nature of the lumbopelvic region, with its maze of bone, muscles, tissues, and nerves, the actual manner in which an injury occurs, or the mechanism of injury, that lead to lower back pain are quite varied.  In some cases, direct injury will result in lower back pain. In other cases, lower back pain inducing forces may be the by-product of another injury. And yet, some back pain may result from the combined effect of two or more pathogenic processes, or be cyclic, a pattern of pain inducing forces repeating in steps. Some examples of these are: a direct injury to a lower back muscle resulting in pain; a painful injured lower back muscle resulting in instability of a vertebral body. The vertebral body shifts and impinges a nerve, resulting in additional pain; or a combination-cyclic effect in an injury to a lower back muscle causing the sufferer to assume an awkward posture. The strained posture triggers spasms in other muscles, the spasms in turn relate to adjacent nerve roots, and result in neural pain. Even though the initially injured muscle might proceed towards recovery, continuing neural pain causes stress and stiffness, and the other affected muscles go into a cycle of pain causing microspasms, the cycle repeating itself over and over, a form of chronic lower pack pain.

In the case of the kendo practitioner it must be remembered that the lumbopelvic region is the focal point of dynamic loads related to locomotion, that is, the offset, compressive loads of propulsion. These loads associated with foot movements, or ashi-sabaki, locomotive body movements, or tai-sabaki, and foot-strike to the floor, or ashi-fumi-komi, are transmitted through the lumbopelvic region. These forces are two-directional, the trunk and head loads at the initial pushing down and away, and secondly, the impact forces upon actual foot-fall, the forces transmitting back up to the trunk and head.

A kendo practitioner who improperly rises and falls, or ‘bounces’ during tai-sabaki increases the incidence and extent of compressive loads to their lower back. An over-exaggerated ashi-fumi-komi will not serve as the climax to a forward movement or contribute to rapid follow-up of the trailing leg, but rather, multiply several-fold the loads to the lower back, and impede smooth forward locomotion. Examples of these types of patterns can occasionally be seen in improperly executed kiri-kaeshi (also, uchi-kaeshi.)

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A kendo man or woman who relies on a violent, corkscrew-like, trunk twisting action to facilitate abrupt 180 degree direction changes, as opposed to utilizing footwork, applies great compression forces and torsion loads on the vertebral bodies and intervertebral discs. Muscles and ligaments are strained, and the intervertebral notches close like scissors around the nerves passing through them.

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There may also be some environmental factors:  Practice on hard floors, such as the concrete-slab floors often found in sports gymnasiums result in higher peak pressures of push-off and footfall, as compared to wooden floors with suspension.  Propulsion relative to effort if efficient; however, loads to the lower back are great. The period of impact on a concrete slab floor is short, but peak pressures are very high. Conversely, if training on sponge-like surfaces or tatami mats, propulsion is less efficient. Generally speaking, applied against an elastic surface, a given amount of force is applied over a longer period, and peak forces may be lower; however, in reality, an opponent’s ability to recognize an attack and effect low-movement counter-measures does not change. To enable an attack equal to that of one conducted on a rigid floor, greater push-off force is required, resulting in higher peak pressures spread out over a longer period, or “more of more,” so to speak. All these forces are ultimately transmitted to, and through the lumbopelvic region.

The repetitive action of raising-up and swinging the shinai down (furi-kaburi and furi-oroshi, respectively,) and the shock-loads of the impact of the shinai, transmitted through the trunk to the lower back region are also considerable.

Executing a doh attack in which one leans or twists their body excessively, or resorting to jerking motions, this way and that, in order to avoid an opponent’s attack, rather than using tai-sabaki, distance, or maai, or an attack in reaction to the opponent’s attack, or oji-kaeshi-waza, subjects the body to those destructive, off-axis compression loads and torsioning forces described earlier, with regards to abrupt turns.

A kendoist whose left hand falls below their solar plexus, or mizo-uchi, while striking, will invariably lean forward, or ‘hunch’ their shoulders together upon executing techniques, as opposed to extending their left arm directly forward, the left hand in front of the mizo-uchi, while maintaining upright posture.  Not only does the lower left hand position have shorter ‘reach,’ but also, dropping the shinai down in such a way, without the arms reaching full extension, makes shinai-control more cumbersome, adding even more lower back loading.

Leaning forward, or ‘diving’ with head down, or neck ‘craning’ and head tilting back both result in a complex combination of forces and strains on the trunk and lower back. The interval with the opponent should be traversed by propulsion issuing from the legs, sending the hips forward, with the upper body upright and relaxed. The practice of ‘diving-in’ headfirst is not only contrary to proper striking principles, but is also a hazardous type of movement with concern to lower back protection.

These loads resulting from locomotion and shinai manipulation do not only axially compress the vertebral bodies, but the vertebrae are pushed anteriorally and posteriorally, “riding over one another” or translating, while adjusting the body forward and back. These forces come into play in side-to-side, or lateral motion as well, when shifting weight from one leg to the other. The connective tissues, the anterior and posterior longitudinal ligaments that stabilize the spine, are alternately stretched and released. The long muscles spanning longitudinally up and down the back, the erectors, and their counterpart abdominal muscles, although alternately loaded, are under constant requirement to remain flexed. Muscles of the lower torso, and buttocks, are employed as well, compensating for lateral movements.

All these forces and loads I have described may singularly, or in combination, contribute to injuries resulting in spondylogenic and/or neurogenic back pain. They may result in fractures to bone, shearing of chondral surfaces, forcible extraction, or avulsion of intervertebral tissues (commonly: herniated disc.) They may strain or detach muscles or connective tissue. They may cause impingement of, or pressure against, nerves. Neural signals and motor impulses may be impeded in their transmission through injured tissues.

Viscerogenic back pain, although not specific to kendo activity, should be considered by anyone suffering from lower back pain. Gastric aliments, urinary tract infections and stones, inflammation of the liver induced by a hepatitis episode, just to name a few sources, can relate to lower back pain. Women also have special concerns, as their periodic menstruation cycle affects their overall condition, and brings about temporary weight fluctuations. There are the additional concerns of the condition of uterus and ovaries.

Vascular back pain may not be commonly found in the kendo population; however, persons who have any vascular, pulmonary, or blood related ailments should keep these factors in mind, and report them to their caregiver in the advent of lower back pain. Abnormal vessels in the area of, or adjacent to the spine, can apply pressure to the nerves or rootlets, and cause lower back pain that is difficult to detect.

Finally, psychologically induced back pains, although perhaps thought to be purely imagined, do in some cases have basis in actual pathogenic processes. In cases of psychosomatic pain, nervousness and anxiety may result in tension translating to the muscles, resulting in pain. In other cases, anxiety or depression may cause signals to the body’s neural processing “switchboard,” or thalamus, to become mis-directed, resulting in pain. In the case of true psychogenic pain, the patient is mentally ill. Emotional trauma, tragedy in their life, or a hysterical nature may precipitate the complaint of lower back pain.

We have examined the classifications and general aspects of the different causes of lower back pain. While considering these various causes, we may wish to examine the manner and degree of correct execution we are employing in our kendo practice. As we can see, many of the factors, and forces that precipitate lower back pain are accumulative. If we can gain a better appreciation of good posture in the form of correct kamae, efficient locomotion in the form of basic, ashi- and tai-sabaki, and skillful striking in the form of orthodox waza execution, we can enjoy more skillful and beautiful kendo, and a long kendo career, free from back pain.

In the following article, we will examine some representative cases of lower back pain associated with kendo activity, their diagnosis and evaluation, treatment, rehabilitation and physical therapy protocols, and finally, preventative measures every kendo man and woman can implement in their lives to reduce the potential of back injury, and lower back pain syndrome.



R.C. Evans, Illustrated Orthopaedic Assessment, St. Louis, MO, Mosby, Inc. 1994, 2nd ed.J.A. McCulloch,

H. Gray, H.V. Carver, Gray’s Anatomy, New York, NY, Barnes & Noble, 1995, 15th ed.

J.A. Porterfield, C. DeRosa, Mechanical Lower Back Pain: Prospective in Functional Anatomy, Philadelphia, PA, W.B. Saunders Co., 1991

E. E. Transfeldt, Macnab’s Backache, Baltimore, MD, Williams & Wilkins, 1997, 3rd. ed.

Editors, Dorland’s Pocket Medical Dictionary, Philadelphia, PA, W.B. Saunders Co., 1982, 23rd ed.