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Cumulative trauma


Cumulative trauma disorders are disorders that are usually caused by excessive repetitive impact and inadequate scheduling of exercise and rest periods. Cumulative trauma disorders are also known as repetitive strain injuries (RSI).

Cumulative trauma

Cumulative trauma cases often begin as simple muscle pain and fatigue to an overused area of the body. If recognized early, a short period of rest will usually lessen the pain. However, if ignored, it may result in nerve entrapment syndromes, myalgia, tendonitis, tenosynovitis, osteochondrosis, or common repetitive injuries such as "tennis elbow" or "little league arm.” Cumulative trauma to the head can lead to physical and metal insures that can seriously affect a person’s quality of life.

Nowadays, children complete in numerous sports during a single year, which can lead to cumulative trauma disorders. These disorders can have a pronounced effect on the growth and development of these children as they enter adulthood and later, old age.

Some adults continue participating in impact sports that they have participated in since childhood. All the years of cumulative trauma add up until problems begin to manifest. Other adults are just beginning impact sports and are not thinking about the consequences of repetitive trauma. Some people will have negligible effects from cumulative trauma, others will have chronic problems, and some will have debilitating problems as they age.

Types of growth centers

Two types of growth centers are responsible for the growth of bone, the epiphysis, and the apophysis.


The epiphyses are located at the ends of bones, and, in children, the shaft of the bone and the epiphysis is separated by epiphyseal cartilage or plate. This plate provides the means for the bone to increase in length so only growing persons (children) have epiphyses. Being cartilaginous, these epiphyseal plates are vulnerable to the stresses and strains placed on them by repetitive, continual activities.

"Little league elbow" is an example of an injury to the epiphysis of children’s bones. It may be encountered by children who repeatedly throw a baseball during their childhood years. As a normal part of a child’s growth, stress is applied to the epiphysis by the strong pull of enlarging and growing muscles. Coupled with these normal stresses, the repetitive trauma of throwing a baseball can exert a great amount of force on the epiphyses and can injure it.

Bone growth depends on its blood supply and, if the epiphysis is injured, the blood supply will be interfered with, and ultimately growth could be hampered. Injuries to the epiphyses can result in angulation deformities, especially around the elbow, and this can give rise to either cosmetic deformities or modifications in the normal functioning of the limb. Therefore, any trauma to the child resulting in swelling, pain, or an inability to play his or her sport should be x-rayed.


Once adulthood is reached and growth is completed, the epiphyseal plates fuse and are replaced by bone. It is the period before this fusing that is of concern since it dictates the successful "normal" development of a child’s bones.

The apophyses are found at the attachments of muscles and adjust for the longitudinal growth of the bone. They allow tendon and muscle attachments to keep up with growth. Like the epiphyses, the apophyses can be affected by osteochondrosis, a disease of the growth centers of bones in children. This disease leads to compaction, destruction, and an altered architecture of bones. Some type of trauma is needed to begin this dilapidation of the bones, such as that caused by repetitious activity. In adolescents, osteochondrosis is referred to as apophysitis, where the trauma is mainly occurring at the tendon or ligament insertion into a bone.

A common example of this syndrome occurs in children who continuously run on hard surfaces (long-distance runners for example.) or who slam their feet down during certain activities (such as basketball). Here, swelling of the ligaments and tendons surrounding the tibial tuberosity occurs, causing inflammation and extreme pain. The tibial tuberosity is located on the anterior or front of the lower leg. Its job is to provide an anchoring point for the tendons of the quadriceps and secure the patella tendon.

Continued exertion can cause swelling of this area which can be extremely painful. This condition is known as Osgood-Schlatter’s disease. Osteochondrosis is a serious disorder that is affecting more and more children who push themselves and who are pushed to play elite, competitive sport.

Injury rate is low

Although these injuries are very real, the incidence of such injuries is low. To many physicians, the repeated "micro-traumas" that occur over a period to a young athlete’s whole body are just as important as cumulative trauma disorder. These micro-traumas are experienced by footballers for example, who put their bodies through the rigors of a full-contact sport from a young age - resulting in such problems as stress fractures. All these conditions may lead to problems in later life, and these problems need to be addressed.

The aftermath of epiphyseal plate damage and osteochondrosis can have marked effects on the child’s physical growth and development as he or she enters adulthood and old age. In rare cases, repetitive activities such as tennis and baseball pitching have brought about a stretching of the epiphyseal growth center. Hence, the active arm can become longer than the untrained arm. The stretching of the arm is a characteristic common with professional adult baseball players and tennis players. Even though this bone hypertrophy (bone enlargement) has never been documented as being detrimental to the athlete, it is still important to note that the "normal" growth and development of the child has been impaired through intense, repetitive activity.

This bone hypertrophy is often combined with excessive muscle hypertrophy. Professional tennis players can regularly be seen with larger forearms and biceps on their dominant arm compared to their untrained arm. Rowers, for example, participate in an activity that is very repetitive and can cause a strain on such muscle groups as the pectorals located on the front of the chest. This continued loading on the pectorals leads them to undergo hypertrophy and they become larger and stronger.

Exercising the same muscle group over and over and ignoring the opposing muscle group, may lead to a muscle imbalance. This imbalance occurs when a one muscle group is overworked, such as the pectorals, and the opposing muscle group (in this case, the rhomboids located in the upper back) is underworked. This disturbs body symmetry and puts the athlete at greater risk of strain and pain. If these muscle imbalances are not corrected early in an athlete's career, they may lead to poor posture, instability, and a reduction in the ability to produce smooth movement.

As mentioned earlier, osteochondrosis can have many long-term effects on the human body. Initially, it is associated with tenderness and localized pain and swelling in the area. These symptoms will not persist if treated properly. However, in extreme cases such as Osgood-Schlatter’s disease, a calcification of the tendon and ligament attachments at the tibial tuberosity occurs. This causes an enlargement of the tuberosity which is very painful and limits movement. Some physicians believe that in extreme cases, osteochondrosis may lead to arthritis in old age.

Problems as epiphyseal plate damage and osteochondrosis can have drastic effects on a young child’s body through the adolescent years. If severe enough, they can have a marked effect on the child’s normal development into adulthood and on his or her quality of life in old age. Martial arts instructors should take careful note of the potential damage that can be caused to young bodies by excessive, repetitive high-energy training.

This leads to the question, "How hard should children train?" and "What adjustments need to be made to our martial arts curriculum?"

Damage to a young athlete’s bony structure depends on the type of activity, the intensity and duration of the activity, and the suitability of the child to that activity. The following shows the three main somatotypes (body types) and the activities for which they are best suited.

Body types

Somatotypes and activities suitable for each body type:
  • Ectomorph
  • Predominantly long boned and thin.
  • Suitable for endurance activities, such as long-distance events.
  • Mesomorph
  • Predominantly stocky and muscular.
  • Suitable for power events, such as sprinting, and contact sports, such as martial arts.
  • Endomorph
  • Predominantly round and fat.
  • Suitable for events where buoyancy is an advantage, such as long-distance swimming.
Knowing about the different somatotypes may be used when recommending children to play certain sports. Although children must receive exposure to several different sports, physical educators can direct individuals into activities that would not place too much stress on their bodies. For example, a coach may recommend that an ectomorph does not try to be a baseball pitcher, but perhaps a batter or catcher where the strain on his slender limbs is not as great. Or, a martial arts instructor may suggest a student try another style of martial arts that more suits his or her body type.

Many physical educators have realized the effect repetitive activity can have on the muscular and skeletal systems of our children. Today, organized children's sports have been modified to try to reduce the incidence of cumulative trauma disorders. By trying to increase the involvement of all participants by limiting the amount of influence a select and gifted few can have on the game, cumulative trauma disorders may be reduced.

Martial arts instructors are beginning to introduce resistance training such as weightlifting into their class design or as a part of a child’s training. Children may safely participate in a program of low weights with many repetitions, but the repetitions should be monitored to reduce the risk of injury.
Martial arts instructors need to be aware of the strain various activities can place on a young child’s bones. For this reason, overdoing activities such as excessive punching or jumping, or strength training to a specific area must be avoided. Specifically, excessive kicking of all types should be avoided.


  • McConnell-Brown, L. (1994). Cumulative Trauma Disorders. Sub-title: "Children, physical and sports education, growth, and developmental considerations." Presented on 24/10/94 at Victoria University of Technology.
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