Overview of Sport-Specific Injuries

Shoulder Injuries

Injuries specific to the thrower's shoulder most commonly involve the labrum and undersurface of the rotator cuff. These injuries can be brought on by tissue changes in both the anterior and posterior glenohumeral capsule, that alter shoulder kinematics. Maximal stress to the rotator cuff is exerted during the follow-through phase of throwing, as the cuff musculature functions to decelerate the arm. Since the superior labrum is the attachment site for the long head of the biceps tendon, repeated traction of the biceps tendon with overhead throwing can also lead to superior labrum anterior to posterior (SLAP) tears.

Elbow Injuries

The throwing motion generates significant valgus stress on the elbow and rapid elbow extension. This combination places tension on the medial structures of the elbow, shear stress on the posterior structures, and compression forces on the lateral structures. The combination of this is described as valgus extension overload syndrome, and is responsible for the pathophysiology of most throwing elbow injuries. Medial epicondylitis is one sequela from the syndrome, in addition to ulnar collateral ligament (UCL) sprain or tear from overuse.

Lower Extremity Injuries

The lower extremity is the most frequently injured body part among fielders. Upper leg muscle and tendon strains are the most common lower extremity injury, with hamstring strains being the most common. Knee ligamentous injuries and ankle and foot sprains make up the other large numbers of lower extremity injuries. Most of these injuries occur during sudden sprints, while sliding, or while manipulating one's body to catch a ball.

Young Athlete Injuries

Almost 5 million children and adolescents participate in baseball every year in the United States. Adolescent pitchers are at particular risk for overuse injuries from throwing. Studies have demonstrated a steady increase in surgical rates for pitching-related injuries in immature throwers. In one study, pitching more than 100 innings per year demonstrated a significantly increased risk of injury in the adolescent population. The elbow is most commonly affected, with a spectrum of pathology that includes an apophysitis or avulsion of the medial epicondyle and osteochondritis desiccans of the capitellum or radial head. In the shoulder, an epiphysiolysis of the proximal humerus may develop. Collectively, these conditions are known as “little leaguer's elbow” and “little leaguer's shoulder.” Consensus recommendations include avoiding pitching with arm fatigue/pain, avoiding 80 pitches or more per game (2500 pitches or more per year), avoiding competitive pitching for longer than 8 months per year, and exercising caution and restraint in pitching showcases. In 2008, Little League Baseball guidelines disposed of inning restrictions for pitchers and moved to pitch counts, which were deemed more prognostic from their ongoing studies. Maximum allowable pitch counts per game are as follows: 50 pitches (age 7 to 8), 75 pitches (age 9 to 10), 85 pitches (age 11 to 12), 95 pitches (age 13 to 16), and 105 pitches (age 17 to 18). Depending on the amount of pitches thrown, mandatory rest is enforced as well. For example, if a pitcher aged 15 to 16 pitches 76 or more pitches in a single day, he must take four calendar days of rest before returning to pitching. The guidelines also suggest that youth pitchers take 4 months of rest per year, but this has not been mandated.

Sliding Injuries

In the major league and collegiate levels, sliding injuries are low, accounting for less than 10% of all injuries. In a study of five seasons of Major League Baseball (MLB) play, an injury occurred in about 3 per 1000 slides. Average time loss was 12.3 days if no surgery was required, and 66.5 days if surgery was required, as was the case in 8.2% of injuries. Interestingly, players were almost four times more likely to be sliding into second base for their injury as compared with any other base. Feet-first slides most commonly caused ankle injury, and head-first slides most commonly caused injury to the hand, fingers, or thumb. At the collegiate level, the overall injury rate from sliding was 9.5 per 1000 slides, with feet-first slides resulting in double the amount of injuries as head-first slides. In stark contrast, sliding injuries may represent as many as 70% of all injuries sustained in recreational baseball and softball. Presently, low-impact or breakaway bases are available, and have been shown to significantly reduce the amount of injury caused by sliding.

Ankle Sprains

Ankle sprains are the most common diagnosed injury in both male and female basketball players, accounting for 25% of all basketball injuries overall. Neuromuscular training and external ankle supports were found effective in significantly reducing ankle sprain incidence. One study estimates that seven basketball players need to undergo neuromuscular training (consisting of a 9 week balance training program) for it to effectively prevent one ankle injury. Ankle braces work by reducing the weight-bearing and non-weight-bearing inversion range of motion (ROM) at the ankle, increasing muscle activation and excitability, and decreasing joint velocity.

Knee Injuries

ACL injuries are common in basketball. Females are two to four times more likely to sustain ACL rupture as compared with males, with a 16% chance of occurring sometime during their career. Neuromuscular training has failed to show any tangible benefit in ACL rupture prevention in the basketball population in specific. ACL injury prevention programs are successful in other sports such as soccer, team handball, and volleyball.

Tendinitis

The patellar and Achilles tendons are vulnerable to overuse tendinopathies from the repetitive eccentric loading involved in jumping. Patellar tendinitis (“jumper's knee”) is the most common overuse injury in basketball. In junior basketball, its prevalence is reported as high as 10%. Risk factors include high jumping, deep knee flexion during landing, and valgus strain during eccentric load phase of landing.

Finger/Hand

Injuries to the hand are very common in basketball. Most hand injuries (>90%) involve sprains and volar plate injuries of the proximal interphalangeal (PIP) and metacarpophalangeal joints. Dislocations at the PIP joint are common from direct ball contact with axial load. Players are also at risk for avulsion of the extensor digitorum when the ball creates an axial load through the fingertip (“mallet finger”) and avulsion of the flexor digitorum profundus (FDP) when the finger is caught on an opponent's jersey or on the rim during a slam dunk (“jersey finger”). Boutonnière deformity can result from rupture of the extensor tendon central slip; early recognition of this condition is important. Gamekeepers' injuries to the thumb usually occur as a result of a fall to the floor or an extension load to the thumb while blocking an opponent.

Facial/Dental Injury

Facial injuries are more common in male basketball players as compared with female players. Dental injuries are composed of fractures, avulsions, and oral lacerations. Ocular trauma is common from contact with opponents' fingers or elbows and can result in corneal abrasions, retinal detachments, hyphemas, lacerations, contusions, and fractures. Nasal fractures may occur, either from a blow by the opponent's elbow or from head-to-head contact.

Concussion

Concussion is common in basketball, particularly during the physical contact of rebounding a ball under the basket. As in other sports a prior history of concussion is a predictor for repeat injury and should be evaluated during preseason examination. Every concussion should be managed on site and have medical clearance before returning to play. Consensus guidelines exist to guide medical staff on recognizing and appropriately managing players with suspected concussion.

Sudden Death

Basketball is a high-intensity sport with moderate static and high dynamic cardiac demands. It is estimated that up to 35% of sudden deaths in sport occur in basketball. The majority of these deaths were classically thought to result from occult hypertrophic cardiomyopathy; however, more recent literature fails to prove this at time of autopsy. Connective tissue disorders such as Marfan syndrome can also induce cardiac abnormalities. With a high preponderance of these disorders in tall people, and the predominantly tall basketball player population, it is important that adequate preparticipation screening with a cardiac-specific history is performed. Twelve-lead ECG and echocardiogram testing may prove useful in the correctly screened population and can potentially detect more than two-thirds of common causes of sudden cardiac death.

Professional Versus Amateur

The majority of the epidemiological study in boxing is done in amateur boxing, where the majority of injuries involves the head and face. Amateur and professional boxing generally share similar rules, including that boxers can only be struck in the face or body; however, the differences in these two types of boxing explain variations in the type of injuries. One of the most obvious differences stems from the protective equipment. Amateur boxers wear protective headgear that shields the head and face from lacerations and orbital fractures. In addition, amateur boxers have limits on the amount of bandage and tape allowed under the boxing glove, which diminishes the weight and momentum of their punches. In professional boxing, there is generally no limit on hand wrapping, and heavier, more protective gloves are worn, increasing the weight and momentum of their punches. There are typically more injuries in competition at both levels because of the desire to maximize the forces of punches.

Facial Injuries

In a retrospective cohort study of competitive amateur boxers, the overall incidence of injuries was 24 for every 100 fights. Injuries including wounds and lacerations to the face and head represented 62% of injuries. In another study of professional boxers, the overall injury rate was 17 per 100 fights, with 51% of injuries involving wounds or lacerations to the face and head. The other injuries evaluated where hand injury and eye and nose injuries. Injuries to the nose are very common often leading to epistaxis often impairing the boxers breathing during a match. The boxers with epistaxis should be evaluated for maxillofacial fractures, septal deviation, and possible septal hematoma. Repetitive trauma to the face can also lead to injuries to the eyes and surrounding structures. Soft-tissue injuries to the eyelids can lead to the development of an expanding hematoma an effectively impair the sights of the boxer. Furthermore, direct impact to the eyes can lead to more serious conditions such as retinal detachment and orbital floor fractures. When suspecting a fracture, the evaluation of the athlete for impaired ocular movement, ptosis, and diplopia should be promptly completed.

Upper Extremity Injuries

Injuries to the hand and wrist are the most common musculoskeletal pathology encountered. Injuries to the hand represents 7% of all boxing injuries. In a cohort study of professional boxers, injury rate for hand and wrist injuries in competition was 347 injuries per 1000 hours, while the estimated injury rate in training was less than 1 injuries per 1000 hours. The most common hand injuries observed were carpometacarpal instability and boxer's knuckle (neck of the fifth metacarpal fracture). Other fractures readily seen in the hand are metacarpal shaft fracture, and first metacarpal base fracture (Bennet fracture). Soft-tissue injuries involving the hand and wrist typically involve the scapho-lunate joint and interphalangeal dislocation. Most of these injuries necessitate a surgical intervention for stabilization. Soft-tissue injuries such as ligament strains are more readily seen than fracture.

Neurologic Injuries

Concussion represents from 10% to 17% of injuries seen in boxing and is the most common neurologic injury encountered. When a boxer is knocked down, there is a brief or prolonged loss of consciousness where the athlete is unable to stand or defend himself. In the majority of cases, the altered mental status lasts for a short period of time. There are cases of more severe trauma to the brain that can lead to death. Subdural hematoma are such cases and should be treated as emergencies. While a boxer can receive more than 100 punches to the head during a boxing match, the repetitive blows to the head through a boxer's career can lead to traumatic encephalopathy. It has been shown that about 17% of boxers can have a central nervous system lesion, which may have been caused by the repeated blow. Other studies have found mid to late stage chronic traumatic encephalopathy in 17% and cerebral or cerebellar atrophy or ventricular enlargement in 50% to 60% of the professional boxers.

Foot Injuries

Figure skates themselves consist of a stiff leather boot and a metal blade. The unique aspects include high heel of the boot—which places the foot into constant slight plantarflexion and the large toe pick on the front of the blade—which is used for some jump take-offs and jump-landings. “Lace bite” is irritation of the tibialis anterior, extensor digitorum, or extensor hallucis longus tendons. This occurs from excessive friction across the tendons, usually from improper placement of the tongue of the skate, and can be mitigated by ensuring proper tongue placement, or using boots with alternative lacing styles. “Pump bump” or Haglund's deformity is a protrusion of the lateral heel. It is caused by an overly wide heel of the boot, allowing the skater's heel to move up and down, and can be mitigated by ensuring optimal boot heel fit. An accessory navicular is present in 4% to 21% of the normal population, excessive friction from a tight boot can make this a symptomatic process. Treatment involves building up the arch of the skate, or having the area of the skate “punched out.” Stress fractures can occur most commonly in the first and second metatarsals. They are caused by the force from jump take-offs, especially when engaging the toe pick of the skate. Treatment involves rest, screening for nutritional deficiencies, and in some cases implementing a “jump count” similar to a pitch count for stress injuries to baseball pitchers.

Ankle Injuries

Ankle injuries are the most common in all of figure skating. They are usually sprains and in fact happen more commonly during “dry land” training as opposed to when on ice. Malleolar bursitis can also occur from friction inside of the boot and is more common on the medial side. Padding the affected malleolus or “punching out” the inside of the skate can mitigate the problem. Achilles tendinitis is common from overuse, thought to happen from the repetitive jumps, or compression from the rim of the boot. Treatments include modifying the rim of the boot, rest, ice, stretching, and eccentric strengthening of the posterior leg musculature.

Knee and Hip/Pelvis Injuries

Patellofemoral pain syndrome and patellar tendinitis can occur from jumping. Repetitive falls while learning new jumps and routines can lead to contusions throughout the lower extremity. Meniscus, ligamentous, and fractures of the lower extremity (outside of the foot and ankle) are actually quite rare.

Since many figure skaters will rotate in the same direction when performing jumps, they can develop an asymmetry in strength and flexibility. Triple and quadruple jumps require a large amount of torque to achieve rotation speed commensurate with the jumps, and can lead to iliac crest apophysitis. Since the iliac crest apophysis is one of the last to close (around age 16 in boys, and age 14 in girls), this can be an ongoing source of pain for teenagers.

Back and Upper Extremity Injuries

Arching trunk extension is a common motion in figure skating and can lead to a myriad of back conditions such as spondylosis, spondylolisthesis, lumbar strain, and facet joint pain.

Upper extremity injuries are rare, and occur more in pairs and dance skaters who have a higher risk of collision during practice and warm-ups compared with singles skaters. This can lead to lacerations, fractures, and even head injuries. These skaters also encounter shoulder and wrist problems resulting from the lifting and throwing elements in their discipline. Synchronized skating can be quite dangerous because of the number of skaters on the ice and the tight formations and maneuvers that they perform. A domino effect often occurs when one skater falls, creating a high risk for lacerations, finger amputations, fractures, and head injuries.

Head and Neck Injuries

Of most concern in this category are concussions. Concussions occur in an estimated 3 million youth athletes, 1.1 million high school athletes, and 100,000 college athletes each year; however, there is also an estimated 27 : 1 ratio of underreporting in college football, particularly among offensive linemen. New consensus guidelines exist to guide physicians and other health care providers. Specific guidelines on when to remove athletes from play are critical, as adolescent and young athletes not removed from play have almost a 10-times risk of prolonged recovery as compared with those removed from play. Though our recognition and treatment of concussions have come a long way, the barriers remain underreporting of injury, premature return to play (RTP), and receiving routine rather than individualized treatment.

Cervical spine injuries are uncommon, but a source of catastrophic injury in football. Due to recent rule changes modifying tackling and blocking techniques, the incidence has decreased—particularly the incidence of catastrophic injuries. Cervical spine injuries are composed of a spectrum of ligament and/or soft tissue damage, fractures, and neurologic impairment. Mechanism of injury is typically an axial load applied to a flexed or extended cervical spine. A “stinger” is neurapraxia of the brachial plexus or cervical spine nerve roots. It occurs in 50% to 60% of collegiate football players at some time in their careers. The mechanism is either from neck hyperextension, lateral flexion, and axial load, or from a direct blow to the brachial plexus.

Upper Extremity

Upper extremity injuries are common in football, comprising about 30% of all injuries, with the shoulder affected most commonly. Quarterbacks are most susceptible to shoulder injuries from throwing (overuse) or resulting from tackles while throwing (traumatic). Shoulder injuries include acromioclavicular (AC)/sternoclavicular joint separations, acute rotator cuff injuries, repetitive strain injuries, subluxations/dislocation, and fractures. Wrist sprains are another common injury, resulting from the heavy trauma to the distal upper extremity during tackling, blocking, and maneuvering other players on both offense and defense. Fractures of the forearm and wrist are an additional common injury, usually resulting from impact with the ground while being tackled or with other players.

Lower Extremity

Lower extremity injuries are the most common type of injury in football. Starting in the thigh, muscle strains and contusions are extremely common. Contusions result from direct blows from the helmet, knee, or shoulder and can lead to bleeding within the musculature, swelling, pain, stiffness, and loss of muscle excursion limiting joint motion. Muscle strains are common in muscles crossing two joints, as they experience higher stress during eccentric contraction, with the quadriceps and hamstrings at particular risk.

Ligamentous injuries in the knee are the most common serious injury in football, and additionally the knee is the most common site of season-ending injury. Players injure their ACL with a reported incidence of 11 to 18 per 100,000 athlete exposures with increasing incidence at higher levels of play. Valgus collapse of the knee is the common mechanism in both contact and noncontact injuries, with a forceful blow causing the former, and usually a sudden deceleration prior to change in direction causing the latter. Though in many sports noncontact ACL injuries are more common, in football contact ACL injuries are in fact more common (55% to 60%). Injury to the medial collateral ligament (MCL) is the most common knee injury at all levels of play, with estimated incidence of 24.2 per 100,000 athlete exposures in high school. In a study examining collegiate athletes presenting to the National Football League (NFL) combine, 23% of offensive linemen had a history of MCL injury. The mechanism (especially in linemen) is thought to be from “chop blocks” and other players “rolling up” on the outside of their legs. Patellar subluxations and dislocations occur in 4.1 per 100,000 athlete exposures in high school. The mechanism is commonly from result of knee flexion with the tibia in a valgus position. Though in general sporting most are from noncontact mechanisms, a majority of football instances (63%) are due to contact, similar to ACL injuries in football players.

Foot and ankle injuries have a reported incidence from 9% to 39%, with as many as 72% of all collegiate players presenting to the NFL combine having a history of foot and ankle injury, and 13% receiving prior surgical treatment. Offensive and “skill position” players are particularly susceptible to foot and ankle injury from high levels of force and torque placed on the distal extremity during running, cutting, and tackling. Lateral ankle sprain is the most common injury. Turf toe is a hyperextension injury and plantar capsule-ligament sprain of the hallux metatarsophalangeal joint and is caused from increasing playing surface hardness and decreasing shoes stiffness. Jones fracture is fracture of the fifth metatarsal at the metadiaphyseal junction, where there is a watershed area of decreased vascularity. The rising rate recently may be due to flexible, narrow cleats that don't provide enough stiffness and lateral support for the fifth metatarsal during running and cutting. Also, lateral overload from baseline cavovarus foot posturing with possible metatarsus adductus and/or skewfoot contributes as well. Most of these are surgically fixed due to a delayed union rate of 25% to 66%, nonunion rate of 7% to 28%, and re-fracture rate of 33% in high-level athletes. Lisfranc injuries are bony or ligamentous damage to the tarsometatarsal joints and occurs commonly from axial loading to a fixed plantar-flexed foot. Noncontact twisting injuries are more common among NFL players, resulting in a purely ligamentous injury. Comparison of weight-bearing radiographs of both feet is crucial to accurate and timely diagnosis.

Lower Back Injuries

Low back pain is common among amateur and professional golfers. This can be primarily attributed to the biomechanics of the golf swing, which has evolved with changes in club technology to produce higher club head velocity at impact. The modern swing emphasizes greater rotation of the thorax through an arc of about 120 degrees. This places the vertebral column in a hyperextended position during the follow through phase of the swing and leads to large lateral flexion and anteroposterior forces on the lumbar spine. In addition, microtrauma to the hip leads to joint contractures and loss of rotation. Therefore, in order to adequately rotate the pelvis and torso for the swing, many golfers need to rotate the lumbar spine past its native rotational capacity. This leads to repetitive microtrauma, which predisposes golfers to paraspinal muscular strains, intervertebral disc herniation, and facet joint arthropathy. In concordance with these findings, most golfers report low back pain primarily during the follow-through phase and radiographs show more degenerative changes in lumbar facets of golfers compared with controls. Other contributors to low back pain can include carrying heavy bags and frequent bending on the course. Finally, many golfers with low back pain can rely on other muscle groups, such as the abdominal musculature, to achieve the same rotation, which can predispose these areas to overuse injuries as well.

Elbow/Forearm Injuries

Injuries to the elbow and forearm are the second most common in golfers after low back injuries. “Golfer's elbow” is the term applied to medial epicondylitis, which typically occurs when the golf club strikes the ground forcefully during the downswing. This traumatic injury typically occurs in players with poor swing mechanics. Lateral epicondylitis, on the other hand, is typically an overuse injury due to repetitive forceful forearm extension along with twisting and is actually five times more common than “golfer's elbow.” Other potential elbow injuries include ulnar neuritis and medial epicondyle avulsion fractures.

Shoulder Injuries

The shoulder is next most common area of upper extremity injury. The lead shoulder (left in a right-handed golfer) is the most commonly affected side. The rotator cuff is active with elevating the club above the head for the address phase of the swing, and players can experience symptoms of subacromial impingement with this activity. Pain from the AC joint can also manifest during this phase of the swing, especially during maximal cross body adduction when forces along the AC joint are greatest. In order to generate more power during the downswing phase of the swing, many golfers will rotate their shoulder joint as much as possible, which can lead to microtrauma to the joint capsule and labrum, leading to symptoms of glenohumeral instability. Posterior instability is more common than anterior, and many golfers will have a positive load and shift test on exam. SLAP tears and biceps pathology are also possible, but less common than other true overhead sports.