Common Injuries in Group Exercise

The focus of this article  is to create an awareness of injuries, the occurrence of which is somewhat common to the group exercise class setting. Recognition of injury potential, common injuries, and first-aid responses may be instrumental in protecting students, instructors, and even the activity itself. The decision to teach exercise programs comes with inherent responsibilities. These responsi­bilities include, yet are not limited to, the ability to instruct participants through a safe and effective exercise session, provide first-aid when appropriate, and refer participants to health care providers. Therefore, it is important for fitness professionals to be knowledgeable in exercise science, the various injuries that can occur during participation in physical activity, and trained in first-aid. However, it is just as important that fitness professionals do not go beyond their professional boundaries. Only health care providers can diagnose and treat injuries. Therefore, referral to a health care provider will always be necessary for service beyond first-aid.

In order to conduct a quality exercise program, the instructor must have a basic understanding of the exercise sciences (anatomy, physiology, and kinesiology), the principles of fitness conditioning and, in addition, must be able to recognize the potential for injury. Additionally, the instructor must have the skills necessary to transfer this knowledge into a practical setting.

Since its origin nearly two decades ago, group exercise programs have attracted millions of enthusiastic participants. The numerous benefits obtained from group exercise programs are well documented and demonstrate the validity of this sport. However, like any form of exercise, group exercise classes carry a certain potential for injury. Fortunately, the potential for injury can be minimized by the prudent instructor.

A review of the scientific studies performed regarding injuries in group exercise classes demonstrates similar findings. The majority of injuries sustained in group exercise classes are reported by the instructor. In fact, four times as many instructors than participants have suffered from the repetitive stresses of aerobics. These findings concur with similar research in that overuse is most commonly associated with injuries in group exercise classes. The injuries tend to occur in the lower extremities, with the majority, reported in the lower leg and foot.

Safety Considerations in Class

Floor Surface

The nature of group exercise classes provides movement patterns that multiply the gravitational forces on the body. Therefore, a resilient floor surface that will give and absorb impact is recommended. Exercise on concrete or other hard surfaces is never recommended. Texture of the floor also needs to be considered. Carpeted surfaces present a greater risk of hip, knee, and ankle torque if proper technique is not demonstrated and taught.

Proper footwear is the most valuable piece of equipment for the group exercise participant. A shoe that provides adequate cushioning will help protect the lower extremities from impact shock. A shoe designed specifically for the biomechanical actions of cardiorespiratory fitness (aerobics) or other group exercise movement is preferred. That is, the shoe should provide support and cushioning in the metatarsal region where the initial impact lands. The longi­tudinal arch should be properly supported, and the heel counter should be firm and stable. Footwear must be carefully selected to accommodate the individual’s foot structure and type of activity.


Improper progressions are often exhibited by novice exercisers. Frequently, overzealous participants will begin with and/or rapidly advance to a regimen that is beyond their physical capacity (or at too high of an intensity). The result is, as one might suspect, muscle soreness, fatigue and possibly injury. This is the primary reason that new participants drop out. A recommendation of muscle conditioning and low-impact programs may be appropriate for the unconditioned participant. Certainly, the novice exerciser should begin with the minimum recommendations, such as 3 days per week, 20 minutes of aerobic activity performed at approximately 40 to 60% of heart rate reserve (HRR).

Progressions that follow should be limited to one variable at a time, never increasing by more than one variable per week. The prudent instructor will not hesitate to advise students in this regard and help them modify when necessary.

Improper or Insufficient Warm-up

The warm-up period is designed to prepare the body for the exercise that will follow. The combination of rhythmic limbering exercises and short preparatory stretching is believed to reduce potential for injury. This, however, continues to be a debatable topic. In general, exercise selection for the warm-up period should mimic the work to follow and be appropriate for the group setting (modifications for some individuals may be required). Students should be advised of the importance of the warm-up period and encouraged to arrive to class on time to engage in such activity.

Inferior Choreography

Exercise selection should be carefully reviewed so that a training effect can be achieved with minimal stress to the body. This is, to some extent, specific to the population involved. The experienced and prudent instructor will consider many factors to minimize injury potential in class. Choreography should be such that repeated stresses over one body part arc avoided. Higher stress movements should be interspersed with lower stress activities, and should begin only after an appropriate warm-up. Movement patterns should be carefully choreographed to avoid sudden, rapid changes in direction. Modifications should be frequently included to accommodate all levels of fitness.

It is important to remember that the instructor’s responsibility does not end with class design. Careful supervision and instruction is vital to ensure safety of exercise. Even the most carefully planned and well-executed exercise programs carry a certain potential for injury. It is important for instructors to be familiar with the common injuries associated with fitness programs. Instructors must also recognize the limits of their training, and refer all injuries to medical professionals for evaluation and treatment.

Body Mechanics

Maintenance of proper posture and body mechanics are essential components of injury prevention. The body should be erect and a natural alignment should be maintained. Particular attention must be given to the knees and spine. Exercise selection should allow participants to maintain proper alignment and not place unnecessary stresses on vulnerable joints. For example, when weight bearing, the hip, knee, and foot should be facing one direction to avoid torque at the knee. Instructors should carefully monitor participants throughout the class for proper body alignment.

Postural Misalignments

Postural misalignments, such as genu valgum (knock-knees) or genu varum (bowlegs), may predispose participants to injuries. Students with known postural misalignments, who have had pain in the past, or who experienced an injury that has not completely healed as a result of exercise should be referred to a health care provider.

Postural deviations of the spine may lead to difficulties in exercise performance and/or injury to the participant. A certain degree of deviation is common as no two individuals are exactly alike. However, excessive spinal deviations, such as scoliosis, lordosis, or kyphosis, may result in increased injury potential. The injury may be a direct cause of the deviation itself, or a result of postural compensation.

Scoliosis, a lateral curvature of the spine, usually occurs in the thoracic region. This deviation often prevents the participant from maintaining proper spinal alignment and may result in pain or injury. However, not all individuals with scoliosis are symptomatic, as symptoms vary according to the degree or severity of the deviation. Although diagnosis should be made only by a health care provider, scoliosis may be recognized by observation of different shoulder heights of the individual when the individual bends forward and is observed from behind.

The causes of scoliosis may be structural or functional. Functional scoliosis is a result of a muscular imbalance between the right and left sides of the body. Exercise programs that address muscular imbalances are often used by the therapist to correct or alleviate functional scoliosis. Congenital, or structural, scoliosis is difficult to manage with exercise. Students with suspected scoliosis or who experience symptoms should be referred to a health care provider for evaluation prior to activity.

The low back, or lumbar spine, is designed to have a degree of curvature, known as posterior concavity. Excessive curve of this region, termed lordosis, is associated with an anterior tilt of the pelvis. Although lordosis may be congenital in nature, it is often a result of tight hip flexor and back extensor muscles and weak abdominals. Strengthening of the abdominal musdes and stretching of the hip flexors and back extensors may alleviate this condition. Individuals with lordosis who experience musculoskeletal or neurological pain or discomfort should be referred for medical evaluation prior to activity.

Norinal curve of the thoracic spine is known as posterior convexity. Excessive curvature of this region is properly termed kyphosis. Kyphosis is often seen in older women and could be a result of osteoporosis or osteoarthritis. Other common causes of kyphosis include muscular imbalances, inflammation of the spine, and poor posture. Kyphosis may be identified with a rounded appearance of the shoulders, tight pectoral muscles, and overstretched middle trapezius and rhomboid muscles. Treatment administered by a physician or other health care provider will vary according to cause and severity.

Inadequate Muscle Strength/Muscle Symmetry

Group exercise classes, high-impact choreography in particular, present impact loads or stress to the body. Adequately developed musculature will help absorb and disperse the shock of impact throughout the body and will, therefore, reduce injury potential. It may be advisable for the novice exerciser to begin with a muscle conditioning program and/or low-impact activities to decrease injury potential. Instructors should include exercises to help develop muscular endurance/strength and be aware of the agonist/antagonist relationship. Imbalances between opposing muscle groups may predispose participants to injury.

Poor Flexibility

Flexibility refers to range of motion and joint mobility, and is specific to joint design. Although flexibility does not directly relate to health, it is a key component of fitness. The importance of flexibility exercises is sometimes ignored. Just as hypermobility may compromise stability within a joint, inflexibility of the musculotendinous structures may predispose participants to injury. Acute muscle injuries are more likely to occur when the muscle fibers or surrounding tissues are taut and incapable of withstanding sudden forceful stretches. Instructors should include a carefully planned series of static stretches at the end of each class and encourage participants to partake, and stay within their physical boundaries, in this very important segment.

Acute Versus Chronic Injury

The most common type of injury in group exercise is chronic or long term in nature. When excessive, repeated stress is placed on one area of the body over an extended period of time, the tissue may begin to fail. This failure results in a chronic injury, often called “overuse syndrome.” There is no specific trauma or incident that causes the injury and symptoms may persist for months with little change and/or frequent acute exacerbations. An acute injury has a sudden onset due to a specific trauma, such as twisting your ankle. If the symptoms of an acute injury are ignored and the tissues continue to be stressed, the injury may become chronic. For example, a groin pull or hip adductor tendinitis can originate acutely from an excessive or fast lunging lateral movement. Rest, Ice, Compression, and Elevation (RICE) as first-aid responses should be implemented initially for such conditions. If these first-aid measures do not prove effective, the injury could become chronic. In such circumstances, participants should be referred to their health care provider.


Providing a safe environment for participants is one of the primary responsibilities of a group exercise instructor. A safe environment includes the means to deal effectively with emergencies when they arise. The most basic of these means is a comprehensive first-aid kit for the response to minor injuries. Response to an acute injury, as stated previously, consists of RICE: Rest, lee, Compression, and Elevation. (NOTE: Instructors should recommend participants seek medical advice and/or care following any form of injury.)

Rest is necessary for proper healing to occur. Recommendations for rest depend upon the severity of the injury, and vary from modifications of the exercise program to complete non-use. Ice is used to decrease swelling and diminish pain. Ice can be applied directly in the form of ice cups or ice packs, or indirectly through a plastic bag or towel. “Real ice,” or a package of frozen vegetables (e.g., peas), are preferred over “chemical ice” which does not melt or freeze safely and may over-cool the tissues. Icing should be stopped (usually no longer than 10-20 minutes) when the skin begins to turn pink and can be applied repeatedly every 2-3 hours with breaks in between of 30-40 minutes in duration. Recommendations regarding the duration of ice application vary from 2-3 days, or until no further swelling is present. If ice application is not effective within that time period, the service of a health care provider should be obtained.

Compression also helps to decrease swelling. Ace bandages and elastic wraps are examples of compression devices, and they may be used in conjunction with ice. The area above and below the injury should also be included in the wrapping to ensure even compression. If the injury is in the foot or the ankle, do not remove the shoe as this provides compression. Removal of the shoe could also dislodge a fracture and cause further injury.

Elevation of the injured area helps to decrease swelling, so long as the afflicted area is raised above the level of the heart. For example, to sufficiently elevate the lower extremity, one must lie supine with the lower extremity elevated and supported versus sitting with the lower extremity at the same level as the hip.

For injuries that persist and/or increase in discomfort or swelling, a physician should be consulted as soon as possible. Also a health care provider should be consulted for any injury that involves joint pain or in which the affected area appears out of alignment.

Common Injuries

The following are the most commonly reported injuries in group exercise. Appropriate response is suggested for each injury, but it is strongly recommended that all pain be evaluated and treated under a physician’s care. While fitness professionals cannot diagnose in a medical sense, the following may be helpful in rendering appropriate first-aid response to certain injuries. Patello Femoral Arthralgia (Chondromalacia Patella) is an overuse injury affecting the articular cartilage of the posterior surface of the patella, or kneecap. Common symptoms are:

Generalized pain that tends to increase with weight-bearing knee flexion activities (such as squats), walking up or down stairs, or sitting for a long period of time with bent knees swelling, grinding or grating noises, pain in the knee with flexion or extention. The exact cause is unknown and may be multivariable. Abnormal lateral tracking of the patella in the groove of the femur is a contributing factor. Excessive weight bearing during knee flexion, an abnormally positioned or shaped patella, and ankle or hip deviations worsen the patellar tracking and cause inflammation. An effective response may include ice for acute exacerbations, and a change of activity may be required. Strengthening the quadriceps muscle group and correcting abnormal foot motion may also help. A health care provider’s evaluation and treatment is required as necessary.

Shin splints is a catch-all term for pain occurring in the anterior or lateral lower leg, and is the most frequently reported injury in group exercise. The majority of the pain is located in the anterior-tibialis muscle, resulting from tibial periostitis and/or stress fractures of the tibia. Treatment varies from RICE to immobilization with no weight-bearing activity allowed. If any numbness or weak­ness occurs in the foot distal to the site of anterior tibial pain, a condition called an­terior compartment syndrome could be the cause which may need to be treated surgically. Participants with changes in sensation and strength of any body part should be referred immediately to a physician or other health care provider, as should any others who require more than simple first-aid attention.

Anterior compartment syndrome is a very common injury in running. It is a condition involving the three muscles in an anterior compartment of the leg:

(a) the tibialis anterior, (b) extensor hallucus longus, and (c) extensor digitorum longus. These muscles all perform ankle dorsiflexion. If these muscles are overworked, the condition may lead to swelling of the muscles and pressure to the fascia encompassing the muscles. This pressure may restrict blood flow to the muscle and lead to pain, numbness, and paralysis. This condition can be a medical emergency. If first-aid responses are not sufficient, health care intervention by a licensed provider is necessary.

Metatarsalgia is a term used for generalized pain and/or tenderness in the metatarsals, the heads of the long bones of the foot. Possible etiology is degenerative changes in the arches of the feet and/or excessive or repeated force on the ball of the foot, as in jumping. If first-aid does not relieve the pain, a health care provider’s evaluation is needed. Plantar fasciitis refers to inflammation of the fascia or connective tissue of the plantar or bottom surface of the arch of the foot. Pain commonly originates near the calcaneal insertion (heel) of the fascia and will progressively radiate towards the ball of the foot with increasing severity of inflammation. RICE, heel cushions, and arch supports are possible therapeutic measures. Again, if first-aid responses do not work (after a few days), medical evaluation is necessary.

Stress fractures are microscopic fractures that occur usually to a weight-bearing bone, such as tibia (leg bone) or metatarsals (foot bones). Pain is usually localized to one area and reaches a crescendo during activity. The fractures are usually due to repeated stress or overuse of the area. These fractures occur gradually and are not usually seen in X-rays during the early stages. Health care-provided treatment may vary from a recommendation of modifications in impact to complete non-weight bearing, by use of crutches. A stress fracture in the femur is a more serious form of stress fracture which may be present with diffuse hip pain. Potential or actual stress fractures always need medical evaluation.

Tendinitis is inflammation of the connective tissue that joins a muscle to a bone. The Achilles tendon is prone to this injury in group exercise. This is the common tendon of the gastrocnernius and the soleus muscles of the calf muscles. It inserts into the back of the heel bone. First-aid response (RICE) and a cushioned heel lift may assist. The underlying condition needs to be evaluated and treated by a licensed health care provider. Stretching before and after exercise may be key in prevention.

A sprain is a tearing or overstretching of a ligament. A ligament is connective tissue that connects bone to bone. Sprains are classified as first, second, or third degree depending upon the severity. Recovery length can vary from days to months. Ligaments may be permanently deformed, thereby increasing a participant’s potential for injury in future activities. Fitness professionals should recommend first-aid and assessment by a physician to determine severity and need for bracing. A strain is an overstretching or tearing of a muscle or tendon. Severity can range from a minimum of torn fibers up to complete tearing from the bone called an avulsion. First-aid should be recommended, followed by early assessment by a physician.

The injuries discussed in this article are the most prevalent in the group exercise class setting. The prudent instructor will regard this information as the basis for a medical referral and not diagnose injuries or recommend treatment.

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