A. Muscle exercise types
1. Isoinertial exercises
a. Isoinertial exercises, often incorrectly referred to as isotonic exercises, involve applying a muscle contraction throughout a range of motion against a constant resistance or weight.
b. These exercises are beneficial in that they strengthen both the primary and synergistic muscles, as well as provide stress to the ligaments and tendons throughout varying ranges of motion.
2. Isotonic exercises
a. Isotonic exercises involve applying a muscle contraction throughout a range of motion against a constant muscle force.
b. These types of muscle contractions are rarely used and may involve the use of free weights, such as dumbbells or weight devices.
3. Isometric exercises
a. Isometric exercise can be defined as a process by which a muscle is contracted without appreciable joint motion.
b. These exercises are used often as the first form of strengthening after injury or with individuals who are immobilized.
c. These exercises can help improve static strengthening and minimize the extent of muscular atrophy.
4. Isokinetic exercises
a. Isokinetic exercise refers to a type of strengthening protocol in which the speed of a muscle contraction is fixed but the resistance varies depending on the force exerted throughout a range of motion.
b. Maximum muscle loading is postulated to occur throughout the entire range of motion.
c. These exercises are performed using machines that automatically adjust the resistance throughout the range of motion, including active dynamometers.
d. Isokinetic testing is used frequently to assess the progress of rehabilitation as well as to objectively determine whether full muscle strength has been regained following an injury.
B. Muscle contraction types
1. Concentric muscle contractions are contractions in which the individual muscle fibers shorten during force production and the origin and insertion of a particular muscle group move closer to one another.
2. Eccentric muscle contractions are contractions in which the individual muscle fibers lengthen during force production and the origin and insertion of a particular muscle group move apart from one another.
C. Training types
a. Sport-specific exercise is characterized by or related to a specific sport.
b. An example of sport-specific training exercise for hockey is rollerblading, or in-line skating.
a. Periodization is a planned workout scheme in which the volume and/or the intensity of training is varied over a set period of time.
b. Periodization of training can generally be divided into phases throughout the year, such as conditioning, precompetition, competition, and rest.
a. Plyometrics is a form of resistance training that involves the eccentric loading of a muscle followed by immediate concentric unloading of a muscle to create a fast, forceful movement.
b. Plyometrics trains the muscles, connective tissue, and nervous system to effectively carry out the stretch-shortening cycle.
c. This training modality emphasizes spending as little time as possible in contact with the ground and may include exercises such as bounding and hopping drills, jumping over hurdles, and depth jumps.
D. Joint motion
1. Active range of motion
a. Active range of motion is the process by which the individual moves a joint or muscle group without help from another person or machine.
b. Active range of motion allows for assessment of a patient's willingness to perform the movement, muscle strength, and joint range.
2. Passive range of motion is the process by which another person or machine moves a joint or muscle group of an individual.
E. Types of stretching
1. Active stretching
a. Active stretching is also referred to as static-active stretching.
b. An active stretch is one in which a position is held with no assistance other than using the strength of the agonist muscles.
c. The tension of the agonists in an active stretch helps to relax the muscles being stretched (the antagonists) and is referred to as reciprocal inhibition.
d. Many of the movements (or stretches) found in various forms of yoga are active stretches.
e. Active stretches are usually difficult to hold and maintain for more than 10 seconds and rarely are held longer than 15 seconds.
2. Passive stretching
a. Passive stretching is a stretching technique in which the muscle being stretched is relaxed without any movement to increase the range of motion; instead, an outside agent creates an external force, either manually or mechanically.
b. This position is then held with some other part of the body, with the assistance of a partner or some other apparatus.
c. A seated hurdler's stretch for the hamstrings is an example of a passive stretch.
3. Proprioceptive neuromuscular facilitation (PNF)
a. PNF is any type of stretching technique combining passive stretching and isometric stretching.
b. The technique involves a three-step process in which a muscle group is passively stretched, then isometrically contracted against resistance while in the stretched position, and then is passively stretched again by postisometric relaxation through the resulting increased range of motion.
c. PNF stretching usually employs the use of a partner to provide resistance against the isometric contraction and then later to passively take the joint through its increased range of motion.
F. Open versus closed chain exercises
1. Open chain exercises are movements, usually with some type of resistance, in which the hand or foot is not in direct contact with a solid object, such as the floor or a wall.
2. In open chain exercises, the foot, or end of the kinetic chain, is moved freely.
3. Closed chain exercises are exercises in which the end of the kinetic chain or foot is fixed to the ground or a wall or is otherwise weight bearing and not able to move freely.
4. In practical terms, open chain exercises involving the knee, such as leg extensions, are postulated to create greater shear force across the knee and its ligaments, especially the anterior cruciate ligament (ACL); closed chain exercises, such as leg presses or squats, are postulated to result in greater compression force at the knee and ACL, which is hypothesized to lead to decreased strain on the ACL during the postsurgical rehabilitation process.
a. Ultrasound is used to apply thermal (deep heat) energy from 2 to 5+ cm below the skin surface, or nonthermal deep massage by using acoustic energy (0.8 to 3.0 MHz) transfer using a round-headed wand or probe that is put in direct contact with the patient's skin.
b. Sound waves are absorbed by various tissues, causing the production of heat.
c. The greatest rise in temperature occurs in tissues with high protein content, such as muscle, tendon, and nerve.
d. Relatively little increase in adipose tissue temperature occurs with ultrasound treatment.
e. Most ultrasound treatments are from 3 to 5 min in duration.
f. Contraindications for ultrasound use include bleeding disorders, cancer, or a cardiac pacemaker.
g. Ultrasound should not be used for most acute injuries with edematous or necrotic tissue.
2. Pulsed ultrasound
a. Pulsed ultrasound is used when localized deeptissue massage is desired to reduce edema in an acute injury situation.
b. Pulsed ultrasound does not result in increased deep localized heating.
3. Phonophoresis—a noninvasive method of delivering medications to tissues below the skin using ultrasound
4. Neuromuscular electrical stimulation (NMES)
a. NMES is a therapeutic modality technique using a wide variety of electrical stimulators, including burst-modulated alternating current ("Russian stimulator"), twin-spiked monophasic pulsed current, and biphasic pulsed current stimulators.
b. NMES has been used for muscle strengthening, maintenance of muscle mass and strength during prolonged periods of immobilization, selective muscle retraining, and control of edema.
c. NMES may be beneficial early in the rehabilitation phase when swelling is persistent and reflexively inhibiting muscle activation.
d. Contraindications to the use of NMES include use in patients with a demand-type pacemaker, or use over the carotid sinus, across the heart, or over the abdomen of a pregnant woman.
5. Transcutaneous electrical nerve stimulation (TENS) is another form of electrical stimulation that has been used to control a wide variety of both acute and chronic pain symptoms.
6. High-voltage stimulation (HVS)
a. HVS is the delivery of a monophasic pulse of short duration across the skin and into acutely injured, swollen tissue.
b. HVS works by acting on negatively charged plasma proteins, which leak into the interstitial space and result in edema.
c. In the setting of an acute injury with edema, a negative electrode is placed over the edematous site and a positive electrode at a distant site.
d. A monophasic, high-voltage stimulus is applied, creating an electrical potential that disperses the negatively charged proteins away from the edematous site, resulting in reduced swelling.
e. Injuries commonly treated with HVS are acute ankle and knee sprains as well as postoperative joint effusions.
f. HVS is often applied concurrently with the more common methods of acute swelling reduction—ice, elevation, and compression.
g. Contraindications to the use of HVS are similar to electrical stimulation.
7. Ice, or cryotherapy
a. Cryotherapy is the modality used to cool tissue.
b. Cryotherapy techniques are done at temperatures ranging from 0°C to 25°C.
c. Depending on the application method and duration, cryotherapy results in decreased local metabolism, vasoconstriction, reduced swelling/edema, decreased hemorrhage, reduced muscle efficiency, and pain relief secondary to impaired neuromuscular transmission.
a. Heat is any superficial modality that provides pain relief by using external warming methods, ranging from 37°C to 43°C.
b. Traditionally categorized by method of primary heat transfer
i. Conduction (hot packs, paraffin baths)
ii. Convection (hydrotherapy, moist air)
iii. Conversion (sunlight, heat lamp)
c. Indications for the application of heat may include painful muscle spasms, abdominal muscle cramping, menstrual cramps, and superficial thrombophlebitis.
a. Iontophoresis involves the delivery of a charged medication through the skin and into underlying tissue via direct current electrical stimulation; this results in a transdermal form of medicine delivery.
b. The charged molecules are placed under an electrode of the same polarity and repelled into the area to be treated.
c. Many ionic drugs are available, including dexamethasone, lidocaine, and acetate.
d. Dexamethasone is the medication most commonly used for treating locally inflamed tissues due to tendinitis, bursitis, or arthritis.
e. Currently, iontophoresis is used in the medical management of inflamed superficial tissues such as lateral epicondylitis, shoulder tendinitis, patella tendinitis, etc.
II. Rehabilitation Phases of Common Sports Injuries
A. Rehabilitation of the anterior cruciate ligament
1. Initial phase after ACL tear or ACL reconstruction
a. Early rehabilitation after ACL injury and reconstruction is similar in that the goal is to minimize pain and inflammation while obtaining good quadriceps muscle activation and full extension range of motion.
b. Ice and compression are used to treat pain and inflammation with either a commercially available joint cooling system or crushed ice with a compressive wrap.
c. Elevation is also important in minimizing swelling because placing the limb in a dependent position leads to pooling of edema in the distal leg.
d. Patients should use an assistive device during ambulation until good quadriceps function and a minimally antalgic gait are achieved.
2. Quadriceps function
a. Acquiring good control of the quadriceps as soon as possible is critical.
b. Beginning the day of injury or surgery, the patient should contract the quadriceps muscles as tightly as possible while the knee is in full extension with a small bolster under the Achilles tendon.
c. Straight-leg raises should begin only after the patient can perform a strong quadriceps contraction in which the heel lifts symmetrically with the opposite side, because straight-leg raises can be performed with relatively poor quadriceps function using the hip flexors.
d. Some patients have severe quadriceps inhibition. In this situation, high-intensity electrical stimulation or assisted eccentric lowering exercises may be helpful in improving activation.
3. Range of motion
a. Efforts should be directed toward obtaining extension range of motion equal to the opposite side as quickly as possible.
b. Although having a strong quadriceps muscle and early ambulation in full weight bearing are the most effective methods of obtaining full extension, patients sometimes still struggle with gaining full extension.
c. In these circumstances, low-load, long-duration stretching is helpful in inducing tissue creep and gaining motion.
d. This exercise should not be painful because this will induce counterproductive muscle guarding.
e. In extremely challenging cases, an extension promotion brace or drop-out casting is helpful.
4. Tailoring rehabilitation
a. Rehabilitation programs should be tailored to the individual, although general principles apply to all patients.
b. Aquatic therapy may be helpful.
c. Strength and control of the entire lower extremity and core are important.
d. Because ACL injury and reconstruction have a particularly severe impact on the quadriceps muscles, this muscle group needs to be treated especially aggressively.
e. The optimal approach includes the combined use of open and closed kinetic chain exercises.
f. Closed kinetic chain exercises should be the primary method of strength training.
g. Rehabilitation exercises need to be performed with an appropriate volume, intensity, and frequency to provide the stimulus for strength improvement.
h. Neuromuscular training using cushions, disks, balance boards, perturbation training, and/or commercially available devices is used to progressively improve dynamic joint stability.
i. Cardiovascular training is advised to promote general health and deliver optimal blood supply to healing tissues.
5. Return to play
a. The decision on when it is "safe" to resume running is case dependent.
b. Running is generally safe 8 to 12 weeks after injury/surgery as long as it is in a straight line and progresses gradually.
c. Agility exercises and multidirectional training generally begin about 12 weeks after injury/surgery.
d. Continued aggressive strengthening is important because most patients still have quadriceps atrophy and strength deficits at the time they are released to sports participation.
e. The return-to-sports decision should be based on a confluence of signs, including patient-based outcomes measures, examination, and indicators of neuromuscular status such as functional tests and strength tests.
f. Thresholds for strength and hop tests should be reasonable (80% to 85% of the opposite side) and considered in light of the big picture of a patient's status because the validity of such tests as predictors of short-term function is questionable.
B. Ankle ligament injury rehabilitation
1. Lateral ligaments
a. Ankle ligament trauma, the most common sports injury, can involve sprains of the lateral, medial, and/or syndesmosis ligaments.
b. One of the most well-established treatment modalities for acute injury of the ankle ligaments is RICE (rest, ice-cooling, compression, and elevation).
c. Cooling decreases tissue temperature, which in turn reduces blood flow and metabolism.
d. Cooling also appears effective in reducing swelling and limiting pain up to 1 week after the index injury.
e. For minor (grade I) and moderate (grade II) tears of the lateral ankle ligament complex, early mobilization of the injured ankle is recommended, with protection provided by the combination of a brace and an elastic wrap; this approach provides protection from rein-jury and compression and has been shown to produce excellent short- and intermediate-term outcomes in >95% of patients.
f. For severe (grade III) sprains of the lateral ligaments, functional treatment produces similar excellent short- and intermediate-term outcomes.
g. A subgroup of severe sprains does not respond well to functional treatment; patients with these injuries may become candidates for surgical repair if recurrent giving-way episodes of the ankle are experienced.
h. After swelling is controlled, weight-bearing status is restored, and ankle range of motion is reestablished, a rehabilitation program that includes sensory-motor, strength training, and sport-specific exercises is recommended.
i. For minor, moderate, and severe ankle ligament sprains, a 10-week sensory-motor training program that includes balance exercises should be completed.
ii. During the sensory-motor training program, muscle strengthening and sports specific exercises should be implemented and progressed.
i. Loss of strength and its subsequent recovery takes time and is dependent on the severity of the index injury.
j. Return to play is usually indicated when full ankle range of motion is restored, full muscle strength is regained, sensory-motor control of the ankle is reestablished, and the joint is pain-free during activity with no swelling as a result of activity.
2. Syndesmosis injuries
a. It has been estimated that up to 20% of patients presenting with the more severe lateral ankle ligament sprains have an associated injury to the distal tibiofibular articulation, or syndesmosis (ie, the anterior inferior tibiofibular, interosseous tibiofibular, and/or posterior inferior tibiofibular ligaments).
b. These injuries can range from minor tears of the syndesmosis (which are considered stable) to significant injuries that involve disruption of the syndesmosis combined with fracture of the fibula (which are unstable).
c. It is important to educate the patient with regard to the longer time interval required for rehabilitation and recovery of injury to the syndesmosis ligament complex in comparison with isolated injury to the lateral ankle ligaments.
d. Treatment of injuries to the syndesmosis without a fracture of the fibula requires particular attention to maintaining anatomic reduction of the ankle mortise and syndesmosis.
e. If the syndesmotic injury is considered stable, the treatment should include the use of RICE combined with a posterior splint with the ankle in a neutral position and non-weight bearing for at least 4 days.
f. This is followed by partial weight bearing with crutches and the use of a walking boot or ankle stirrup brace and then progression to full weight bearing as tolerated.
g. After obtaining control of swelling, restoration of weight-bearing status, and reestablishing ankle range of motion, the same sensory-motor, progressive strength training, and sport-specific exercise program described for the treatment of lateral ankle ligament sprains is recommended.
h. Treatment of syndesmotic tears within 12 weeks of injury that are considered to be unstable may require reduction of the syndesmosis with screw fixation.
i. Rehabilitation of these severe injuries includes protection for 12 weeks followed by the program described for stable syndesmotic injuries.
j. Treatment of chronic (>12 weeks after the index injury) syndesmotic injuries may require reconstruction of the syndesmosis.
C. Shoulder instability rehabilitation
1. Rehabilitation of the patient with shoulder instability is highly dependent on the type of instability (traumatic versus atraumatic or acquired), the direction of instability (anterior, posterior, or multidirectional), the treatment approach (nonsurgical versus surgical), and, in surgical patients, the procedure used (open versus arthroscopic techniques).
2. The goal early after a traumatic instability event or shoulder surgery is to minimize pain and inflammation.
3. Crushed ice or a commercially available joint-cooling system is the primary method of treating pain and inflammation.
4. Minimization of the effects of immobilization is a priority.
a. This is accomplished by performing gentle passive range of motion in the "safe" range of motion.
b. Range of motion should increase progressively within the "safe" limits for the specific procedure.
5. Surgeons should clearly determine whether there are any unusual risk factors and what the "safe" limits are for each patient throughout the rehabilitation process.
6. Rehabilitation programs should be tailored so that they are specific to an individual's unique circumstances.
7. Submaximal isometric exercises are performed within the "safe" range of motion early in the rehabilitation process to minimize muscle atrophy.
8. Electrical stimulation and/or biofeedback training is often used as adjunct atrophy-prevention methods.
9. When it is "safe," range of motion is progressed using wand exercises, joint mobilization, and low-load, long-duration stretching that promotes gentle creep of the tissues.
10. Developing a stable platform for shoulder movement through scapular stabilization exercise is a prerequisite to aggressive rotator cuff strengthening.
11. Most shoulder strength programs begin with resistance training using exercise bands, cords, and free weights.
12. As strength and control develop, patients are progressed to various resistance-training devices and plyometrics.
13. Neuromuscular control is facilitated by performing reactive training and various exercises that perturb shoulder stability.
14. Care should be taken to promote appropriate responses to perturbations rather than rigid cocontraction because this strategy of joint stabilization is inconsistent with agile movement and skilled performance.
15. The final stages of rehabilitation should involve sport-specific training and the development of skill in sport-specific tasks.
16. Interval training programs, video analysis, and the input of coaches are helpful in obtaining high success rates when treating overhead athletes.
17. Although adjunct measures of patient status such as strength testing can be helpful, return to sports participation is dependent on the ability to perform sport-specific tasks in a pain-free manner and patient-based outcomes.
III. Prevention of Common Sports Injuries
A. ACL tear
1. Female athletes have a rate of ACL injury that is two to eight times that of male athletes.
2. Unfortunately, surgical intervention does not change the odds of developing knee osteoarthritis after injury.
3. Researchers have developed ways for clinicians to identify athletes at risk for ACL injury and have begun to use training programs designed for ACL injury prevention.
4. Efforts to prevent ACL injury in female athletes should focus on the factors that make females more susceptible to injury and develop interventions to aid in the prevention of these injuries.
5. A meta-analysis by Hewett and associates attempted to quantitatively combine the results of six independent studies drawn from a systematic review of the published literature regarding ACL injury interventions in female athletes.
a. All three studies that incorporated high-intensity plyometrics reduced ACL risk, but the studies that did not incorporate high-intensity plyometrics did not reduce ACL injury risk.
b. Conclusions from this meta-analysis include that neuromuscular training may assist in the reduction of ACL injuries in females athletes under the following conditions.
i. Plyometrics and technique training are incorporated into a comprehensive training protocol.
ii. Balance and strengthening exercise may be used as adjuncts but may not be effective if used alone.
iii. The training sessions are performed more than once per week.
iv. The training program lasts a minimum of 6 weeks.
B. Ankle ligament sprains
1. The fundamental premise of prevention of ankle ligament injuries is that they occur not randomly but in patterns that reflect the process of the underlying causes.
a. Consequently, it is important to understand the risk factors for these common injuries.
b. Not only does this facilitate the development of prevention programs, but it also allows the identification of those at increased risk of injury so an intervention can be targeted at them.
2. One of the most significant risk factors for a lateral ankle ligament sprain is a previous ankle injury.
3. In addition, reduced dorsiflexion, poor proprioception, increased postural sway, and strength imbalances of the muscles that span the ankle have been associated with increased risk of sustaining an inversion ankle ligament injury.
4. Recognizing that one of the most important risk factors for an ankle ligament injury is a prior ankle ligament tear, adequate rehabilitation following an ankle injury before returning to sports participation is an important consideration.
a. This includes the concept of progressive strength training of the muscles that span the ankle complex and sensory-motor training of the lower extremity.
b. Sensory-motor training programs that include a minimum of 10 minutes of balance training 5 days a week for at least 10 weeks, with activities such as single-leg stance on an unstable balance pad or balance board training, can have a dramatic effect on improving sensory motor control.
5. The risk of sustaining an ankle ligament injury (or reinjury) can be minimized with the use of taping or bracing.
a. There is evidence that taping is of value in preventing ankle injuries, but a taped ankle loses as much as 40% of the ankle range of restrictiveness following 10 minutes of exercise.
b. Because of the problems associated with taping, the use of ankle bracing has increased in recent times.
Top Testing Facts
1. Bench press with the use of free weights is an isoinertial exercise.
2. Isotonic exercises apply a muscle contraction throughout a range of motion against a constant muscle force.
3. Isometric exercises involve muscle contraction without appreciable joint motion.
4. Isokinetic exercises occur when the speed of a muscle contraction is fixed but the resistance varies depending on the force exerted through the range of motion.
5. Plyometric exercises such as bounding and hopping are effective in ACL injury prevention programs.
6. Initial treatment of ankle sprain should be RICE.
7. PNF involves a three-step stretching technique combining passive stretching and isometric stretching.
8. Female athletes have a risk of ACL tears that is two to eight times that of their male counterparts.
9. Closed chain exercises are exercises in which the foot is fixed to the ground or a wall.
10. Periodization is a planned workout in which the volume and/or intensity of training is varied over time.
11. Shoulder rehabilitation for instability is highly dependent on the type and direction of instability and any surgical intervention.
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