Regular exercise is a critical component of staying healthy and improving overall quality of life. Exercise can help people maintain a healthy weight, live longer, feel better, and create a healthy state of mind. Exercise can help to control or prevent such conditions as diabetes, hypertension, heart disease, obesity, and even improve bone strength.
The Centers for Disease Control and Prevention (CDC) defines recommended physical activity level as being moderately intense activity greater than 30 minutes' duration at least 5 days per week or vigorous activity for 20 minutes' duration 3 days per week. In 2003, the national average of those meeting this definition was 45.9%. In contrast, in 2005, this number has increased to 48.1% (6). In 2004, the CDC reported upon a survey looking at the percentage of American residents who participated in physical activity other than routine daily activity in a given month. The results showed that more than 67% of Americans did participate in some form of physical activity (7). These reports show a positive trend of more people engaging in physical activity than ever before.
As the number of individuals who participate in physical activity and exercise increases, the roles of personal trainers, strength coaches, exercise physiologists, and athletic trainers will change. A greater number of individuals will seek instruction and direct training to achieve their fitness and health goals. Because many of these individuals will have no previous experience with exercise, their bodies will undergo physical changes due to the new added stressors placed by the exercise program. In many instances, weight training will be a component of their new exercise regimen. Advances in exercise physiology and research related to the aging process have contributed literature proposing the advantages of weight training for the preservation of muscle and bone, reduction of body fat, and improved overall appearance (38).
During the past 1 to 2 decades, exercise and weight training have taken on a much greater role in the general population rather than just athletics. One of every 3 American men and 21% of the overall population participates in weight training-related activities (38). This increase in weight training of previously untrained individuals has also increased the risk of acute and overuse injury from tissue overload (21). The majority of pain associated with strength training is a result of tendon injury from the acute stresses of weight training or repetitive loading and overuse of the musculotendinous region (21,37). As weight training gains popularity, safety, injury prevention, and treatment is a growing concern. Weight training often requires the use of high muscular contractions and more explosive movements, resulting in greater muscular force generation (5). This increase in force generation can overload certain areas of the body.
The lateral aspect of the elbow is a common area of pain complaint and dysfunction associated with upper-extremity activity. Weight training involves a high volume of gripping activity from either grasping a bar, dumbbell, or handle to perform exercise for numerous body regions. The increase in grasping and force required to perform the lift may cause irritation to the musculotendinous region of the lateral elbow if the body is not used to the volume, intensity, or type of grasping. Incorrect grasping or poor wrist control can lead to over activity of the wrist extensors and cause irritation. The remainder of this article will look at a description of lateral elbow pain, an anatomical and pathological overview of the region, a clinical presentation and identification of the signs and symptoms associated with the disorder. This will be followed by modifications that can be made to an exercise and training program, as well as treatment referral.
LATERAL ELBOW PAIN
Lateral elbow pain is a common term used to describe pain that is originating on the outside aspect of the elbow. It occurs in the dominant arm in 75% of the population (37). The development of pain at this region of the elbow is believed to be caused from overuse and is prone to recurrences. Typical symptoms may last in some degree for up to 24 months (13,29,30,34) with 80% of the cases better at 1 year regardless of the treatment intervention (10). The epidemiology of lateral elbow pain in the general population is 3%, accounting for about 5 to 7 general practitioner visits per every 1,000 (28,34). It is highest in patients between the ages of 45 and 64 years (2,20,28,33,36), with more than 50% of these seeking medical attention (33). Lateral elbow pain is reported to be 2 to 3.5 times greater in those older than the age of 40 years and greatest among those who weight-train or participate in athletic activity greater than 2 hours per day (21,23). There is no general consensus regarding whether gender has an effect. Wilson reports an equal prevalence between men and women (37), whereas Shiri et al. (28) report evidence of a greater prevalence in females versus males. There is some evidence to suggest that those involved in racquet sports have a greater likelihood of developing this condition. Several studies report that 40–50% of tennis players experience this condition at some point, with lateral elbow pain being 5 to 9 times more common than medial elbow pain (3,21).
ANATOMY OF THE LATERAL ELBOW
The anatomical structure of the elbow is designed to allow large ranges of motion for placement of the hand in functional movement positions. The elbow joint complex is composed of 3 bones, the humerus, radius, and ulna. The humerus is the proximal bone that has articulations with both the radius and ulna. The radius lies lateral to the ulna and forms the humero-radial joint. The design of the humerus is such that there are enlargements of certain aspects of the bone to provide attachment points for tendons to generate movement of the skeletal structure. Tendons comprise densely arranged collagen fibers, elastin, proteoglycan, and lipids. An outer sheath contains the neurovascular supply that becomes hypovascular as it reaches its insertion into bone (37). The area of chief concern with lateral elbow tendonosis lies in the enlargement of the humerus known as the lateral epicondyle.
Musculotendinous attachments of the extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor digitorum communis, and the extensor carpi ulnaris make up the group of muscles typically referred to as the common extensor group of the wrist and hand. The ECRL originates from the distal aspect of the lateral supracondylar ridge. The ECRB lies underneath the ECRL and has origin from lateral epicondyle as well as the lateral collateral ligament, annular ligament and intramuscular septum. The extensor digitorum communis arises from the common extensor tendon at the lateral epicondyle, whereas the extensor carpi ulnaris has fibers that originate from the lateral epicondyle as well as the posterior border of the ulna (27). The lateral collateral ligament is a fan shaped ligament that extends from the inferior aspect of the lateral epicondyle and attaches to the annular ligament and to the olecranon process of the humerus. The annular ligament is a circular ligament that encompasses the head of the radius and attaches to the radial notch of the ulna and helps to stabilize the proximal radioulnar joint (19). The brachioradialis muscle originates from the supracondylar ridge of the lateral humerus and is involved in flexing the forearm. The supinator muscle originates from the lateral epicondyle and is a prime mover for moving the hand from a palm down to palm up position. The final muscle originating from the lateral elbow at the common extensor tendon is the extensor digiti minimi (9).
PATHOLOGY OF LATERAL ELBOW TENDINOSIS
There has been much debate in the medical literature as to the correct way to reference this condition. The most common used terminology in the past to encompass most types of lateral elbow pain has been lateral epicondylitis. Evidence suggests that tendinitis and tendinosis are 2 different conditions that occur at separate time frames in the repair process and require different types of treatment. Lateral epicondylitis generally refers to lateral elbow pain that results from inflammation and microtearing of fibers in the extensor tendons of the forearm that occurs during an acute onset of symptoms (27). Histopathological studies throughout the years have identified that there is generally a lack of inflammatory cells in the tissue of patients believed to be experiencing lateral epicondylitis several months after onset of symptoms. Tissue biopsies taken at time of surgery reveal a dense population of fibroblasts, disorganized and immature collagen, mucoid degeneration with no inflammatory cells present (35). Alfredson et al. (1) looked at in vivo microdialysis techniques, which demonstrated normal levels of E2 prostaglandins, a biochemical marker of inflammation signifying the lack of an inflammatory presence. Investigations with ultrasound imaging show calcification and tendon thickening rather than inflammation (20). These findings are consistent with a degenerative condition of typical repeated trauma and scar tissue repair leading to a tendinosis rather than tendonitis supporting the concept of two distinct conditions.
CLINICAL PRESENTATION OF LATERAL ELBOW TENDINOSIS
Understanding how lateral elbow tendinosis presents is important in taking the next step to being able to correctly identify risk factors, make appropriate modifications to exercise programs, or refer individuals to a licensed medical practitioner for further evaluation. There are several key cardinal physical signs present with lateral elbow tendinosis.
The chief complaint of most clients is pain that may originate in the lateral elbow and may radiate into the forearm. Reproduction of this pain commonly occurs with gripping activities, lifts that require a palm-down grip, or lifts that require rotation of the hand from a palm-down to palm-up position such as such as certain dumbbell bicep curls (20). Direct palpation to an area about 5 millimeters distal and slightly anterior to the lateral epicondyle will reproduce the common complaint of pain (27,34). This is the location of origin of the ECRB tendon, the most commonly involved tendon in lateral elbow tendinosis.
Physical examination of the involved arm can also indicate whether injury is present. There may be patterns of muscle atrophy, swelling over the lateral elbow, range of motion limitations and grip strength deficit compared to the contralateral extremity. The client may also report having pain with specific activities during the day that involve forearm muscle activity, such as shaking hands or lifting a gallon of milk.
Structural anatomy of the individual client may predispose him or her to injury when beginning a weight training program. Hyperextension and increased valgus angulation of the elbow, muscle imbalance between wrist flexors and extensors, and generalized weakness of forearm muscles all can contribute to altered force distribution and increased susceptibility to lateral elbow tendinosis (21).
Special tests have been developed to allow individuals an attempt to bias the structures of the lateral elbow in an effort to identify the disorder. There is both an active and a passive test described by Magee for biasing the wrist extensors that originate from the lateral epicondyle. In the passive test, or Mill's Test, whereas palpating the lateral epicondyle area, the client's forearm is pronated, the wrist is flexed fully and the elbow extended. A positive test is indicated by pain over the lateral epicondyle. For the active test, the elbow of the client is stabilized, the client makes a fist in a palm-down position, and then extends the wrist while another person tries to flex the wrist. A positive test is sudden sharp pain over the lateral epicondyle (22). A chair pick-up test has been described by several authors as a provocative maneuver to elicit pain originating from the lateral elbow (25,26). In this test, a chair with a back is grasped in the palm-down fashion and then an attempt is made to lift from that position. Pain reproduction over the lateral elbow elicits a positive test. Maudsley's test is identified as resisting extension of the middle finger. A positive test result is pain reproduction over the lateral epicondyle and implicates the common extensor tendon as originator of pain (14,26).
EXERCISE PROGRAM MODIFICATIONS
If a training client demonstrates characteristics of lateral elbow tendinosis, early modifications to the program or activity need to be made to begin initial recovery by helping to manage the symptoms. Personal trainers, strength coaches, and athletic trainers are becoming the first to be in a position to identify initial problems and have the ability to make quick adjustments that may prevent symptoms from worsening.
The primary impairment with this condition is with the muscular system and its tendinous attachment to the humerus. The initial action that should be taken is to reduce the general repetitive loading of the injured tendon area (37). Complete absence from activity is not recommended unless symptoms are very acute and painful. In this situation a brief period of rest and shift focus on training other body parts and cardiovascular workouts may be beneficial to the client. Activity helps the injured tissue to heal correctly, but it is necessary to make several modifications to prevent overloading the healing tissue. The activities the client performs in training should not exacerbate symptoms. It is imperative to ensure the client is using correct form. Another factor one needs to take into consideration is incidental exercise the training client might be performing. Incidental exercise is activity the muscle is performing from routine work or activities on its own. If the client's general activity involves a high volume of hand and arm gripping activity, this must be taken into consideration when training the client and may require a reduction in volume of training to reduce further exacerbation of symptoms (34).
The first modification is in grip position when performing lifting tasks. Avoid activities that require a palm-down grip, such as a reverse barbell curl or upright rows, until symptoms are eliminated. A palm-up or forward grip allows the client to shift much of the force onto the wrist flexors rather than the injured wrist extensors and allow training to the upper extremity without exacerbating symptoms. Shift a large portion of the training regimen to machine activity involving the upper extremities until symptoms are controlled. Machines generally allow the user to push on the handle with a relaxed grip or open-hand pushing movement. Dumbbell or barbell activity, especially if symptoms are reproduced, should be avoided initially, as these require firm grasping by the client.
For clients who also train for or participate in racquet sports, certain modifications can be made that may help them to continue with their sport during training time. Assessment of their swing mechanics is important to be able to identify the abnormal motions that may be causing stress to the forearm region. Improperly sized grip will also add tension to the forearm muscles and cause overload of stress. A recommendation for grip size is to measure from the proximal palmar crease to the radial aspect of the tip of the ring finger. More specific recommendations can be changing to a graphite frame, reducing the tension of the strings and playing on slower surfaces. Racquet weight as well as string tension can affect forearm muscle activity. The heavier the racquet and tighter the strings, the more force required from the wrist extensors to control the racquet, which can lead to exacerbation of symptoms. This can also be important in weight training as well. By building up the size of the dumbbell or barbell, less tension can be placed on the forearm and more of the normal training program can be performed (27).
Different types of braces on the market claim to help provide relief during activity. Several studies have estimated that up to 21% of those diagnosed with some form of lateral elbow pain will be prescribed a brace (29,31). There has been much controversy over the exact mechanisms of how they work as well as whether they are effective or not at promoting recovery. There are two general types of bracing present, wrist splints and counterforce braces.
Splints are designed to provide short-term support to weakened or injured tissue in an attempt to decrease pain. They have a firm metal or plastic stay that runs along the ventral and dorsal region of the splint. The design is to align the wrist in a neutral position and reduce the amount of activity the wrist extensors are required to perform. Numerous studies have looked into the efficacy of wrist splints in the management of lateral elbow tendinosis. In a study that reviewed 4,614 patients diagnosed with lateral elbow pain resulting from repetitive work related injury, there was no benefit to those who were prescribed a prefabricated splint versus those who were not (10). Dereby et al. in 2005 looked at 253 injured workers with diagnosis of lateral epicondylitis. They compared those who were prescribed prefabricated splints to those who where not and found some interesting results. Their study showed that those who wore splints had longer duration of limited duty, required more medical care, and received more treatment than those who did not wear splints (10).
Counterforce braces are designed to provide a constraint to the forceful muscle contractions at the elbow. They are about 1.5 to 3 inches in width and are strapped around the upper part of the forearm just distal to the forearm muscle bulk. The theory is that they can provide a dispersive pressure around the area of pain, which helps to broaden the area of applied stress, provides a restraint to full muscular expansion, and potentially decreases the force that the muscle can generate (2). In essence, they are attempting to create a new pressure point and reduce the tension on the injured tendons. This will allow the extensor muscles to generate more force within a pain-free range of motion (24). Several researchers have analyzed the ability of the counterforce brace to reduce the muscle activity of the wrist extensors during electromyography analysis (EMG). Groppel and Nirschl looked at EMG activity of the wrist extensors during tennis serve or backhand shot and Snyder-Mackler looked at isometric contraction (2). Both found a reduction in subjects' EMG activity while they were wearing the counterforce brace, suggesting decreased firing of the muscles. Knebel et al. (18) found evidence that suggested that usage of counterforce braces lead to an increase in the fatigability of the forearm extensors and may lead to deconditioning of the musculotendinous areas and potentially cause secondary complications. Other studies found no effect on strength, proprioception, or stretch reflex with wearing the counterforce brace, but did find a higher pain threshold (8,24). Struijs et al. (30) looked at various characteristics of lateral elbow tendinosis, trying to identify whether certain people would respond better to the counterforce brace based upon the ability to alter the pain threshold. Their conclusion was that those clients who had a significant positive painful resisted active wrist extension grip test would benefit most from short-term usage of counterforce brace to maintain activity levels. A study by Van De Streek et al. in 2004 (31) looked at both wrist splints and counterforce braces and determined there is generally no benefit for improving maximum grip strength, pain, or function.
Lateral elbow pain can have a multitude of origins. It is critical to recognize when symptoms are not improving and examination by a licensed medical practitioner is warranted. A full description of the etiology and clinical diagnosis of all the possible disorders are beyond the scope of this article. To follow is a brief description of the more common conditions that present themselves as lateral elbow pain.
One of the main large nerves of the upper extremity, the radial nerve, travels around the posterior humerus and bifurcates into two branches, a sensory branch and the posterior interosseus nerve (PIN). The PIN enters into the supinator muscle at a band of fibrous arch, Arcade of Froshe, at the lateral elbow. Tightness in the supinator muscle, or some of the common extensor muscle groups primarily the ECRB, thickening of the Arcade of Froshe from chronic inflammation, or abnormal tension in the nerve can all lead to strain on the PIN. Primary complaint of PIN syndrome is pain over the lateral elbow, especially after activity, in location similar to lateral elbow tendinosis. There is generally weakness with grasp and pain with resisted activities. The most common form of weakness is with extension of the ring and little finger (4,11,27,35).
Injury to the lateral collateral ligament of the elbow can cause posterolateral rotary instability of the elbow joint. When this occurs, pain is present over the lateral elbow region in the same general area as lateral elbow tendinosis. Because of the instability, pain is generally present with activity (35).
There can be some intra-articular causes of lateral elbow pain. In older clients, osteoarthritic changes of the humeroradial or proximal radioulnar joints, and degenerative changes to the radial head can produce lateral elbow pain. Impingement of the posterior elbow or compartment syndrome of the anconeus muscle may produce this lateral elbow pain complaint (12,27,35).
Pain over the lateral elbow can also be referred from body regions outside the elbow joint itself. Different levels of the spinal nerves can produce pain at different areas of the body based upon the innervation. The 7th cervical spinal level is a common referral of lateral elbow pain and weakness of wrist extension (13,35). Pressure on the nerve root can elicit these symptoms. Pressure can be from degenerative spinal joint conditions, herniated disc, or a space occupying lesion such as a tumor.
Being able to determine the cause and nature of the pain requires specialized training and, often, the performance of clinical or diagnostic testing procedures. It is necessary to be able to understand the potential causes, so that referral can be made to better serve the client in the recovery process.
It is critical to be able to recognize early signs of developing complications from an exercise regimen. Several important factors can contribute to weight-lifting injury. These can include a lack of sufficient warm up and stretching, decrease in conditioning before weight training, poor technique, lack of strength or endurance necessary for the level of training, improperly selected resistance, and fatigue (15–17,32). Proper adjustments need to be made to the technique or program to reduce the pain and prevent recurrence. Referral to medical professionals should be made when symptoms are persisting, worsening, or possibly being referred from another region of the body. It is imperative to address the pain and injury quickly. The longer the client is experiencing pain, the more potential loss of training time and setbacks against their personal goals is likely. The primary goal should be a rapid return to full function and premorbid level of activity.□
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