Robert P. Nirschl MD,MS
Elbow injuries are broadly divided into three categories: single event macrotrauma(acute injuries), single event trauma to tissue made vulnerable by overuse (acute on chronic), and multiple repetition overuse injuries (chronic). Numerous pathologies occur under the spectrum of chronic and acute on chronic injuries. Included in the list are: medial, lateral, and posterior elbow tendinosis, ulnar collateral ligament injuries, osteochondral injuries (postero-medial osteophytes and osteochondritis dissecans), growth plate injuries (little leaguer's elbow), and nerve dysfunctions (anterior [median] and posterior [radial] interosseous nerve entrapments as well as ulnar neuritis).
Tendinosis of the elbow is the most prevalent elbow injury, with an incidence of 1-3% in a population of 15,000 subjects reported by Allander.1 Lateral elbow tendinosis is the most common, with the ratio of lateral to medial tendinosis being 5 to 1, with posterior occurring least often. The presentation will focus on these three injuries: lateral, medial, and posterior elbow tendinosis.
Repetitive overuse injury occurs when the stress on a tendon exceeds its tolerance to resist the stress, potentially resulting in a microtear. When a microtear occurs, tendon cells (fibroblasts) make increased collagen and form cross-linkages with other fibroblasts. It is this cross-linked character of collagen fibrils that gives tendons their strength and enables them to operate under conditions of mechanical stress. However, early collagen fibrils are fewer and reducible.19 Time is needed for the collagen to be synthesized and to mature into stable cross-links. What is also required is the appropriate stress. For healing to occur, tension is required across fibroblasts in order for cells to divide and orient themselves perpendicular along a line of stretch. 11 The stress also stimulates collagen fibrils to orient themselves in a parallel arrangement to the direction of tensile load, allowing them to resist imposed demands. 19 However, when the rate of injury exceeds the intrinsic ability of the tendon cells to repair themselves, tissue damage occurs. If the injurious behavior is continued long enough, degeneration of the tendon results.
Tendinosis Vs Tendinitis Vs Epicondylitis
Kraushaar and Nirschl11 , in their review of tennis elbow, described chronic overuse injuries resulting from multiple microtraumatic events that accumulate to disrupt the internal structure of the tendon and lead to degeneration of the cells and cellular matrix. Kraushaar and Nirschl noted that histopathological studies of tendons suffering chronic injury demonstrate an absence of acute inflammatory cells. Nirschl has called this degenerative process a tendinosis, indicative of the failed intrinsic mechanism of the tendon to heal, rather than a tendinitis. A tendinitis implies an extrinsic blood borne response including the presence of inflammatory cells not evident in the histopathological studies of chronic overuse tendons. Nirschl and Petrone16 described these histopathological changes as angiofibroblastic tendinosis, a distinctly non-inflammatory, degenerative, avascular process involving the formation of immature and disorganized collagen with immature fibroblastic and vascular elements. Regardless of what it is called, noted Kraushaar and Nirschl, tendinosis is the result of failed tendon healing.
The consequences for rehabilitation were delineated by Nirschl and Sobel. 18 The rehabilitative specialist must control abusive activity and provide an environment for the tendon to heal via a properly designed and executed rehabilitative program.
Lateral Elbow Tendinosis
Also known as tennis elbow, previously labeled a tendinitis or epicondylitis in the literature. The lateral epicondyle, which serves as the site of attachment for the extensor-supinator muscle group as well as the radial collateral ligament, is not implicated in the pathology. The pathology lies in the origin of the extensor tendons and the adjacent subtendinous space. Specifically, the origin of the extensor carpi radialis brevis is the primary site of pathology. An estimated one third also have involvement of the origin of the extensor digitorum communis, with the extensor carpi radialis longus and extensor carpi ulnaris less frequently involved. The wrist extensor group falls into the category of tendons particularly vulnerable to injury. The tendons have poor vascular supply, wrap around a convex surface, cross more than one joint and are subjected to repetitive stress. 27 Ellenbecker and Mattalino5 postulated that the medially sloping lateral condyle causes a mechanical disadvantage as the tendons must fulcrum over the radial head when they contract. This, they argued combined with the pronated position of the elbow during backhand groundstrokes, ADLs, and other sport specific activities, predisposes the lateral elbow to stress overload injuries.
Of the group, the extensor carpi radialis brevis (ECRB) is the most lateral. EMG studies have demonstrated that the muscle contracts at a higher level during daily functional tasks and contracts more powerfully during the backhand stroke of tennis. 10 This increases the risk of injury for the ECRB, as higher levels of muscle contraction place increased tensile loads on tendons. A rapid eccentric contraction of a muscle firing at a high level is implicated in the pathology of tendons, as the rapid contraction does not allow for reflex relaxation of the muscle.
The individual with lateral tennis elbow presents with pain and tenderness centered about the lateral epicondyle. Pain is reproduced via resisted wrist extension, resisted grip with the elbow extended, resisted third digit extension, or placing the elbow in an extended and pronated position with the wrist flexed. Additionally, resisted wrist supination frequently reproduces symptoms.
Medial Elbow Tendinosis
Medial tendinosis, or golfer's elbow, presents with pain and tenderness centered about the medial epicondyle of the humerus. The medial epicondyle serves as a site of attachment for the flexor-pronator group as well as ulnar collateral ligament. The primary tendons involved in the pathology are the flexor carpi radialis, pronator teres, and the flexor carpi ulnaris. The three muscles all originate from a common site on the medial epicondyle. Symptoms of medial elbow tendinosis are reproduced via resisted wrist flexion and wrist pronation, as well as extending the elbow with the wrist extended and supinated.
Posterior Tennis Elbow
Posterior elbow tendinosis, sometimes referred to as boxer's elbow, involves the insertion of the triceps into the olecranon of the ulna. Rapid extension of the elbow such as during throwing, punching, and serving motions are implicated in the pathology, as is weightlifting.
Management of Overuse Injuries18
Relief of pain
Protection, Rest, Ice, Compression, Elevation, Medications, Modalities (PRICEMM)
Modify Intensity, duration, and technique of forearm activity
Use of proper size and type of equipment
Modalities are often beneficial in relieving pain. The use of moist heat prior to therapeutic exercise, the gym or home exercise program is encouraged for the purpose of increasing circulation and promoting revascularization of injured tissues.
The use of sensory level high voltage alternating current in conjunction with pre exercise heat or post exercise ice has demonstrated the most beneficial effects at the Virginia Sportsmedicine clinic. One electrode is placed on the lateral border of the elbow and one on the medial border. Other placement options include surrounding the medial epicondyle for golfers elbow or surrounding the lateral epicondyle for tennis elbow. Care should be given to avoid placement of the electrodes in a side-by-side fashion as this will cause the stimulation to stay on the surface of the skin
Ice is an important element in the healing process and should be used any time signs of inflammation or intense pain are present, no matter how soon or long after the injury. Post exercises ice is also recommended and may be done in conjunction with sensory level electrical stimulation to promote pain and inflammation control. The benefits of ice include a reduction in pain, inflammation, and muscle spasm. Time of ice application ranges from 15-30 minutes. Icing over 30 minutes may cause frost bite. To protect the skin a thin layer of cloth between the skin and ice is worthwhile. Avoid icing the ulnar nerve directly when icing the elbow.
While rest is appropriate in the acute elbow, the Virginia Sportsmedicine clinic advocates an alternate definition of rest. Rest is defined as the absence of abusive activity, not absence of activity. All tissues, particularly injured tendons, require tension and motion to maintain health. Total immobilization is obviously contra-indicated as it results in muscle atrophy, weakness, and decreased vascular demands. More specifically, immobilization at the elbow results in limited capsular extensibility, joint stiffness, fibrous fatty tissue adhesions and random alignment of collagen fibers. Changes at the muscular level include loss of myofibrils, decrease in the number of mitochondria, and decreased tension-generating capabilities.
Because individuals with tendinosis experience some degree of discomfort, Nirschl and Sobel devised a classification system to help delineate the significance of the pain. This allows the therapist to better assess the injured elbow and offers guidelines for where to start the individual on the necessary rehabilitation portion of the program.
PHASES OF PAIN
Phase 0: No pain or soreness
Phase 1: Stiffness or mild soreness after exercise activity. Pain is usually gone in 24 hours.
Phase 2: Mild stiffness and soreness before activity which disappears with warm up. No pain during activity, but mild soreness after activity that disappears within 24 hours.
Phase 3: Same as above with mild pain during activity which does not alter activity, disappearing in 24-48 hours. Counterforce bracing may be considered here as well as mild anti-inflammatory medication.
Phase 4: Mild to moderate pain before, during, and after exercise which alters the exercise or activity. ADLs are affected. Phase 4 is indicative of some level of tendon damage.
Phase 5: Moderate or greater pain before, during, and after exercise or activity, forcing the patient to discontinue the exercise. Pain is experienced with ADLs. Usually reflects permanent tendon damage
Phase 6: Phase 5 pain that persists with complete rest. Pain disrupts ADLs, many activities have to be eliminated.
Phase 7: Phase 6 pain with disruption of sleep on a consistent basis. Pain is aching in nature and intensifies with activity.
Pain phases 5, 6, and 7 indicate increasing percentages of permanent tendon damage.
Controlling Abuse and Counter-Force Bracing
The medial and lateral counter-force braces have proven very useful in enabling acute individuals to begin an exercise program as well as in performing ADLs. It is often difficult for people to completely avoid pain provoking work or activities. Consequently, bracing helps by dispersing forces that otherwise would be absorbed at the site of injury, allowing the individual to complete his/her task. The individual is advised to wear the brace during necessary tasks known to provoke discomfort, but for no longer than 2 hours at a time.
Bracing has also proven beneficial in enabling rehabilitating individuals to return to sport. Nirschl detailed the principle of the Counter-Force brace is to give firm yet pliable anatomic support and protection for an expanding muscle and moving tendon, while at the same time allowing freedom of joint movement. The brace decreases internal muscle tension and lends support to injured tendons without pinching blood vessels or nerves or causing excess focal compression. Furthermore, studies have demonstrated decreased muscular activity with use of counter-force bracing. 28
Rehabilitative Exercise Program and Promotion of Healing
The goal of rehabilitation is to promote optimal healing of the injured tissue. Rest and pain relief offer no stimulation to the injured tissue. Injured tendons must increase vascular supply, synthesize new protein, and ensure the collagen matures into healthy tissue.18 Rehabilitation promotes strength, flexibility, and endurance in the injured and adjacent tissue. The S.A.I.D. principle (specific adaptations to imposed demands) is followed whereby demands are placed on the body in order to force the body to make adaptations. These adaptations include neural adaptations such as increased motor unit activation with increased motor unit coordination, recruitment, and firing, as well as intrinsic muscle adaptations including increases in the number and size of myofibrils, in the number of mitochondria and in enzymatic content of the muscle cells. Studies have demonstrated that training increases the tensile strength of tendons as well as promotes invasion of vascular elements in tissue. 25,27
The objective of elbow rehabilitation is total arm strength. Trained muscle is able to absorb more energy prior to failure, and the incidence of injury increases with fatigue. This is because as a muscle fatigues, greater stresses are absorbed by the tendons. A concept the clinic emphasizes is that you cannot play your way into shape. You get in shape to play a sport, not play a sport to get in shape. Consequently, it is the duty of the therapist to better prepare the individual for return to participation in work, recreational activities, and sports.
A study of high school athletes found injury rates in those performing resistive training to be only 26.2% versus 72.4% in those athletes not involved in resistive training program. Furthermore, time required for rehabilitation was halved in those who were on a resistive exercise training program.8 Finally, do not overlook the psychological benefit of physical activity.
The program created by Nirschl and Sobel was designed for medial and lateral tennis elbow (tendinosis), the most frequently encountered overuse injuries of the elbow in the clinical setting. However, the concepts may be applied to other elbow injuries and overuse injuries to other body regions as well.
It is important to assess where the individual falls on the Nirschl pain phase scale. Patients with pain at Phase 5 or greater are started with isotonic exercises without any weight in a pain free range. If the patient is unable to perform anti-gravity wrist flexion, extension, or pronation without pain, the patient is instructed to use the counterforce brace while performing the provoking exercise. Patient's at stage 1-4 on the Nirschl pain scale may be started using a one pound weight per patient tolerance, with Counter-force bracing utilized for those at Phase 3-4. Initial exercises, labeled stage I, are performed with the elbow flexed to ninety degrees and supported on the patient's Lower Extremities.
The patient continues with stage I exercises until he/she may perform 30 repetitions with a three pound weight on two consecutive days without and increase in symptoms. The individual may then progress to stage II exercise, but the resistance is decreased from 3 to 1-2 pounds depending upon patient tolerance. Again consisting of wrist flexion, extension, and pronation/supination, but now performed with a more extended position of the elbow with less support from the lower extremities. Once the patient may perform 30 repetitions with a three pound weight on consecutive days without an increase in symptoms, the individual may progress to stage III of the program. Stage three involves the same exercise of wrist flexion, extension, and elbow pronation/supination, but now performed with the elbow fully extended and unsupported. However, again the weight is decreased from 3 pounds to 1-2 pounds depending upon tolerance as the patient progresses a phase.
Once the patient advances to performing Stage III exercises with a 3 pound weight, frequency is decreased to three times a week.
In addition to the three exercises of wrist flexion, extension, and elbow pronation/supination, patients are instructed to abduct their fingers (splay) against the resistance of a rubber band and squeeze an egg, putty, or a stress ball frequently throughout the day to tolerance. Submaximal squeezes are recommended at first with progressive intensity encouraged as the patient progresses.
An important feature to note about the program is that exercises are performed daily. The patient is started with low resistance high repetition exercise to promote a vascular response and increase endurance. Isotonic exercises are performed once a day, with gripping and finger abduction exercises interspersed frequently throughout the day.
Early in the rehab process, in fact immediately for those grading Phase 5 or below on the Nirschl pain phase scale, light weight high repetition exercises designed to increase rotator cuff and scapulothoracic strength are introduced. Anti-gravity shoulder flexion, abduction, and diagonal patterns using light or no weight are introduced. Prone flexion, horizontal abduction with external rotation, prone rows. and extension with external rotation are also given. These exercise have been demonstrated to elicit a high level of rotator cuff activity. Soon after military press with light or no weight is added as well as sidelying internal and external rotation to patient tolerance. These exercise are added later as they are not as well tolerated in the acute elbow patient. This early exercise program again involves light weights and high repetitions, and even highly conditioned individuals will fatigue with this program.
This is a goal of the program: promoting muscular endurance of the entire upper extremity and improving the resistance of the muscle tendon unit to stress. You achieve this goal by producing fatigue in the tissues of the UE without reproducing pain at the elbow. These exercise constitute a safe, effective way to address the stated goals without placing undue stress on the injured tissue and further exacerbating the patient's condition.
As the patient progresses, sports cord or theraband tubing is added for internal and external rotation at the shoulder. Care is taken not to reproduce any symptoms at the elbow as shoulder external rotation may irritate an acute lateral tennis elbow while internal rotation may irritate an acute medial elbow tendinosis. Additionally, the patient is instructed to maintain a neutral position of the wrist while performing IR/ER about the shoulder.
Resistive exercise machines are also incorporated to patient tolerance, generally when a patient grades 3 or less on the Nirschl pain phase scale. Typical exercises include: a Serratus anterior press on the chest press machine, the Rhomboids and Middle Trapezius on a row machine, and the Latissimus Dorsi on the lat. pulldown machine. Exercises such as Tricep press and dips on the Tricep press as well as Bicep curls are also introduced. A well designed program will produce fatigue in the UE without exacerbating the elbow while addressing the shoulder flexors, abductors, internal and external rotators, shoulder depressors, scapula stabilizers, elbow flexors and extensors, forearm pronators and supinators, and wrist flexors and extensors. Above all else however, do not exacerbate the patient's condition and increase their level on the pain phase scale. Additional exercises for the hand include web finger flexion, and later pronation and supination, and resisted wrist flexion and extension a powerstick. Web pronation/supination and powerstick are not added until the patient is performing stage II exercises with 3 pounds at a pain phase score of 2 or lower.
Rehabilitation End Points18
1. Ability to complete all rehabilitation exercise routines to full frequency and intensity with Phase 2 pain or less.
2. Pain free ADLs.
3. All tests for elbow tendinosis should be negative (i.e. resisted wrist extension and supination and 3rd digit extension should not reproduce pain nor should light passive stretch to wrist extensors).
4. Comparative muscle testing of injured versus non-injured UE. This may include isometric hand grip testing via dynamometer and isokinetic testing of forearm musculature for competitive athletes. Not that the dominant arm is generally 10% stronger in the average individual and may average up to 25% higher in elite athletes.
Once the patient has completed the rehabilitation process, presumably when the injured tissue has been restored to normal health (or as managed care allows), the patient is instructed in a maintenance program. Since ADLs do not maintain conditioned tissue and may actually be detrimental to rehabilitated tissue (along with sports activities), it is critical that the patient adhere to the maintenance program. The principles of the program are as follows:
1. Maintenance exercise are indicated so long as the initial injury producing sport or activity is being continued.
2. Continue the full rehabilitation exercise program for a minimum of 1 month following return to full sport or activity. If no pain is present, the program may be reduced to 2 x a week thereafter on a permanent basis.
3. Failure to comply with program invites re-injury.
Surgery is warranted only when patients fail a quality rehabilitative program. Failure to receive a quality program or months of rest without such a program does not justify resorting to surgery.
Post Operative Care and Intervention
Prior to or following surgery the pts, are provided with the following information regarding their plan of care. Pts. should expect a good bit of soreness about the elbow and are kept in an immobilizer the majority of the time for at least 48 hours. Supine sleeping is encouraged with pillows used to support the involved arm. Pt. are asked to keep full shoulder motion by moving their shoulder fully several times each day. On day one pts. begin to move their fingers and wrist for 2 minutes, 3-5X/day.
Showering on the third day is allowed and pts. are asked to remove their bandages, and gently work the elbow in the shower. After showering a cool blow dryer may be used to dry the wound area. The pt. then applies over the counter brand antibiotic ointment and covers the wound with gauze or a large Band-Aid. On days 3-6 the immobilizer is used only when protection is needed, such as going out in public. Patients are encouraged to limber their elbow, shoulder, wrist, and fingers 4-6X/day.
Ice and prescription strength anti-inflammatory medication is indicated for pain control during the first week of post operative care. Pts. are warned to expect significant deep elbow pain that may last for several weeks. This pain reflects the work done and the normal healing process. Pain and stiffness in the morning and after light use is normal at this stage.
A recheck with the doctor is indicated if any signs of infection are present. Patients are instructed to look for any signs of an "angry" wound such as excessive swelling, redness, excessive heat, oozing from the incision, or dramatically increasing pain. If fever of 100 degrees or more persists for more than one day the doctor should be informed.
For days 7-17 more aggressive limbering is encouraged both in and outside of the shower. By day 17 almost 80% of elbow motion is returned. The arm may be used for light activity only and bracing for writing, typing and light lifting is encouraged. The immobilizer may be used occasionally, but for protection only. The majority of the time the arm should be kept in usual and normal positions.
On days 18-21 the pt. may begin light exercising as per the tennis elbow exercise protocol described above. These exercises should be familiar to those pts. who were involved in preoperative physical therapy intervention. However, a review of progression and proper form is always a good idea. In addition to the core exercises the pts. also begin squeezing a nerf ball to implement grip strengthening. The patients are reminded that the exercises are designed to progressively strengthen but not overly stress the muscles involved. Adherence to the progression is a must. Soreness and fatigue following exercising is normal and ice may be used to help control pain.
By week three the patient should be performing the core exercises with light resistance, usually a 1 lb. weight. In the therapy gym light and progressive use of various isotonic resistive machines is begun. Special emphasis is given to the rotator cuff muscles and scapulothoracic stabilizers. In addition to the core elbow exercises being performed at home the therapist at his/her discretion may begin to add cuff and scapular strengthening exercises to the home regimen. During the 3-6 week period patients should notice a decrease in their pre-surgery pain level and as such increased use of the arm is generally noted. Good aerobic training is helpful with use of a bike, treadmill/jogging, stair master or other type machines that do not overly stress the upper extremities. An increase during this stage of healing may indicate that the pt. is over doing it and needs to tone back his/her activity level.
On average the arm is performing normally for activities of daily living in 2 months and for competitive sports in 6 months. Discomfort during the one year following surgery is normal and ice in conjunction with aspirin, acetaminophen or ibuprofen at these times may help. Use of a counter force brace for strenuous and repetitive activity is wise. Contact with the doctor and therapist is encouraged and required for pain lasting more than 5 days. Depending on the level of use required by the patient, post operative physical therapy, usually beginning on week 3, may last anywhere from 6-8 weeks to 4 months.
Techniques and Racquet Design18
It has been suggested that the techniques used by the skilled tennis player versus the novice player may be vastly different and explain the tendency to see a larger proportion of novice tennis players who suffer from tennis elbow.
The unskilled player may demonstrate a leading elbow with the backhand stroke, thus placing greater strain on this area at ball contact. Ball contact in the unskilled player may occur to far from the fulcrum lever, i.e. the shoulder. This causes an increase in torque being absorbed through the UE and greater arm fatigue. The one handed back hand requires greater coordination of movement from 5 body parts as opposed to 2 body parts with the 2 handed back hand. And again, the one handed back hand causes an increase in torque being absorbed by the UE. Excessive spin has been implicated in causing tennis elbow as well as general deconditioning and lack of UE strength. The novice player will also tend to have more missed hits occurring near the racquet periphery, which leads to increased vibration, jarring and twisting of the frame and players hand.
The skilled player tends to hit the ball in the center of the racquet head, also refereed to as "the node", more often than the unskilled player. The node is the center of the racket or slightly above it towards the tip and is considered the ideal area of impact. The tighter grip used by the more skilled player tends to dampen vibrations more quickly. The skilled player will also tend to use the more energetically efficient two handed back hand.
When selecting the ideal racquet a number of optional should be considered for the player plagued with tennis elbow. The frame should be made of stiffer material that will deform less. These tend to be racquets made with more graphite or more material in general. The more thick framed wide body models have been suggested. Lighter racquets allow for more use and thus contribute to more over use. Repetition of motion is the primary cause of tendinosis. With the lighter racquets there is more jarring and shock to be absorbed through the arm. The heavier racquets allow less recoil with the ball and there is less twisting associated with off center/off axis hits. String stiffness is not a factor when considering vibration through the frame, and thus antivibration stoppers or clips placed in the strings will not prevent frame vibration.
The ideal grip is one that allows a great amount of power with the stroke with minimal vibration transmitted to the hand. The tight grip will increase the power of the stroke and increase the magnitude of vibrations transmitted through the hand. The looser grip will conversely show a decrease in power and vibration. Elite players should be encouraged to use a tight grip while novice and unskilled players should use a light to moderate grip.
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