After an anterior shoulder dislocation, the risk of a future dislocation is about 20%. This risk is greater in males than females.

Women in sports such as association football, basketball, and tennis are significantly more prone to ACL injuries than men. The discrepancy has been attributed to gender differences in anatomy, general muscular strength, reaction time of muscle contraction and coordination, and training techniques.

Gender differences in ACL injury rates become evident when specific sports are compared. A review of NCAA data has found relative rates of injury per 1000 athlete exposures as follows:

- Men's basketball 0.07, women's basketball 0.23

- Men's lacrosse 0.12, women's lacrosse 0.17

- Men's football 0.09, women's football 0.28

The highest rate of ACL injury in women occurred in gymnastics, with a rate of injury per 1000 athlete exposures of 0.33

Of the four sports with the highest ACL injury rates, three were women's – gymnastics, basketball and soccer.

According to recent studies, female athletes are two to eight times more likely to strain their anterior cruciate ligament (ACL) in sports that involve cutting and jumping as compared to men who play the same particular sports (soccer, basketball, and volleyball). Differences between males and females identified as potential causes are the active muscular protection of the knee joint, the greater Q angle putting more medial torque on the knee joint, relative ligament laxity caused by differences in hormonal activity from estrogen and relaxin, intercondylar notch dimensions, and muscular strength.

High school athletes are at increased risk for ACL tears when compared to non-athletes. This risk increases with certain types of sports. Among high school girls, the sport with the highest risk of ACL tear is soccer, followed by basketball and lacrosse. The highest risk sport for boys was basketball, followed by lacrosse and soccer. Children and young athletes may benefit from early surgical reconstruction after ACL injury. Young athletes who have early surgical reconstruction of their torn ACL are more likely to return to their previous level of athletic ability when compared to those who underwent delayed surgery or nonoperative treatment. They are also less likely to experience instability in their knee if they undergo early surgery.

A rotator cuff tear can be caused by the weakening of the rotator cuff tendons. This weakening can be caused by age or how often the rotator cuff is used. Adults over the age of 60 are more susceptible to a rotator cuff tear. According to a study in the Journal of Orthopaedic Surgery and Traumatology the frequency of rotator cuff tears can increase with age. The study shows the participants that were the ages of 70–90 years old had a rate of rotator cuff tears that were 1 to 5. The participants who were 90+ years old the frequency of a rotator cuff tear jumped to 1 to 3. This study shows that with an increase in age there is also an increase in the probability of a rotator cuff tear.

According to a study in the Journal of Orthopaedics the prevalence of a rotator cuff tear was considerably greater in males than in females within the ages of 50–60 years old, within the ages of 70–80 years old there wasn’t much difference in prevalence. The data of this study showed that the prevalence of a rotator cuff tear in the general population is 22.1% Yamamoto et al. performed a medical examination on 683 people whom live in a mountain village. The purpose of this study was to determine the prevalence of a rotator cuff tear among a population. Yamamoto found that among the mountain village population, rotator cuff tears were present in 20.7% of the village population. In both of these studies we see that the percentages of the prevalence of a rotator cuff tear are very close in number so these numbers show us the prevalence of rotator cuff tears in the general population.

In an autopsy study of rotator cuff tears, the incidence of partial tears was 28%, and of complete rupture 30%. Frequently, tears occurred on both sides and the frequency increased with age. The frequency was also higher in females. Other cadaver studies have noted intratendinous tears to be more frequent (7.2%) than bursal-sided (2.4%) or articular-sided tears (3.6%). However, clinically, articular-sided tears are found to be 2 to 3 times more common than bursal-sided tears and among a population of young athletes, articular-sided tears constituted 91% of all partial-thickness tears.

The meniscal tear is the most common knee injury. A meniscal tear tends to be more frequent in sports that have rough contact or pivoting sports such as soccer. The meniscal tear is more common in males than females. The ratio is about two and a half males to one female. Males between the ages of thirty-one and forty tend to tear their meniscus more frequently than younger men. Females on the other hand, seem to be more likely to tear their meniscus between the ages of eleven and twenty. People who work in straining jobs such as construction or pro athletes are also more likely to have a meniscal tear because of all the different tensions of their knees. According to the United States National Library of Medicine, the isolated medial meniscal tear occurs more frequently than any other tear associated with the meniscus. The prevalence of meniscus tears is the same for both knees. In a few different studies the BMI of a person can have a greater effect on the frequency of a meniscus tear because having a higher BMI will result in more weight on the joints which can cause the knee to be non-aligned which causes more weight on the muscles resulting in an easier tear. In 2008 the U.S Department of Health and Human Services reported a combined total of 2,295 discharges for the principal diagnosis of tear of lateral cartilage/meniscus (836.0), tear of medial cartilage/meniscus (836.1), and tear of cartilage/meniscus (836.2). Females had a total of 53.49% discharges while males had 45.72%. Individuals between the ages of 45–68 years had an average of 31.73% discharges followed by age group 65–84 with 28.82%. The average length of stay for a patient diagnosed with torn menisci was 2.7 days for males and 3.7 days for females. There was a report of 6,941 hospital discharges for knee repair. Individuals between 18–44 years of age were among the highest with 37.37% total of discharges followed by the age group 45–64 with a percentage of 36.34%. Males had a slightly higher number of discharges (50.78%) than females (48.66%). The average length of stay for both male and female patients in a hospital setting was 3.1.

A SLAP tear or SLAP lesion is an injury to the glenoid labrum (fibrocartilaginous rim attached around the margin of the glenoid cavity). SLAP is an acronym for "superior labral tear from anterior to posterior".

Although strains are not restricted to athletes and can happen while doing everyday tasks, however, people who play sports are more at risk for developing a strain. It should also be noted that it is common for an injury to develop when there is a sudden increase in duration, intensity, or frequency of an activity.

About 25% of people over the age of 50 experience knee pain from degenerative knee diseases.

Several symptoms are common but not specific:

- Dull, throbbing, ache in the joint which can be brought on by very strenuous exertion or simple household chores.

- Difficulty sleeping due to shoulder discomfort. The SLAP lesion decreases the stability of the joint which, when combined with lying in bed, causes the shoulder to drop.

- For an athlete involved in a throwing sport such as baseball, pain and a catching feeling are prevalent. Throwing athletes may also complain of a loss of strength or significant decreased velocity in throwing.

- Any applied force overhead or pushing directly into the shoulder can result in impingement and catching sensations.

In the United States, more than US $3 billion is spent each year on arthroscopic knee surgeries that are known to be ineffective in people with degenerative knee pain.

The incidence of Hill–Sachs lesion is not known with certainty. It has been reported to be present in 40% to 90% of patients presenting with anterior shoulder instability, that is subluxation or dislocation. In those who have recurrent events, it may be as high as 100%. Its presence is a specific sign of dislocation and can thus be used as an indicator that dislocation has occurred even if the joint has since regained its normal alignment. The average depth of Hill–Sachs lesion has been reported as 4.1 mm. Large, engaging Hill-Sachs fractures can contribute to shoulder instability and will often cause painful clicking, catching, or popping.

Tear of a meniscus is a common injury in many sports. The menisci hold 30–50% of the body load in standing position. Some sports where a meniscus tear is common are American football, association football, ice hockey and tennis. Regardless of what the activity is, it is important to take the correct precautions to prevent a meniscus tear from happening.

A study containing 100 consecutive patients with a recent anterior cruciate ligament injury were examined with respect to type of sports activity that caused the injury. Of the 100 consecutive ACL injuries, there were also 53 medial collateral ligament injuries, 12 medial, 35 lateral and 11 bicompartmental meniscal lesions. 59/100 patients were injured during contact sports, 30/100 in downhill skiing and 11/100 in other recreational activities, traffic accidents or at work.

An associated medial collateral ligament tear was more common in skiing (22/30) than during contact sports (23/59), whereas a bicompartmental meniscal lesion was found more frequently in contact sports (9/59) than in skiing (0/30). Weightbearing was reported by 56/59 of the patients with contact sports injuries whereas 8/30 of those with skiing injuries. Non-weightbearing in the injury situation led to the same rate of MCL tears (18/28) as weightbearing (35/72) but significantly more intact menisci (19/28 vs 23/72). Thus, contact sports injuries were more often sustained during weightbearing, with a resultant joint compression of both femuro-tibial compartments as shown by the higher incidence of bicompartmental meniscal lesions. The classic "unhappy triad" was a rare finding (8/100) and Fridén T, Erlandsson T, Zätterström R, Lindstrand A, and Moritz U. suggest that this entity should be replaced by the "unhappy compression injury".

Dead arm syndrome starts with repetitive motion and forces on the posterior capsule of the shoulder. The posterior capsule is a band of fibrous tissue that interconnects with tendons of the rotator cuff of the shoulder. Four muscles and their tendons make up the rotator cuff. They cover the outside of the shoulder to hold, protect and move the joint.

Overuse can lead to a buildup of tissue around the posterior capsule called hypertrophy. The next step is tightness of the posterior capsule called posterior capsular contracture. This type of problem reduces the amount the shoulder can rotate inwardly.

Over time, with enough force, a tear may develop in the labrum. The labrum is a rim of cartilage around the shoulder socket to help hold the head of the humerus (upper arm) in the joint. This condition is called a superior labrum anterior posterior (SLAP) lesion. The final outcome in all these steps is the dead arm phenomenon.

The shoulder is unstable and dislocation may come next. Dead arm syndrome will not go away on its own with rest—it must be treated. If there is a SLAP lesion, then surgery is needed to repair the problem. If the injury is caught before a SLAP tear, then physical therapy with stretching and exercise can restore it.

It is common among baseball pitchers as they age, and it can also occur with quarterbacks in football and handball players also as they age.

Inferior dislocation is the least likely, occurring in less than 1%. This condition is also called luxatio erecta because the arm appears to be permanently held upward or behind the head. It is caused by a hyper abduction of the arm that forces the humeral head against the acromion. Such injuries have a high complication rate as many vascular, neurological, tendon, and ligament injuries are likely to occur from this mechanism of injury.

Gamekeeper's thumb and skier's thumb are two similar conditions, both of which involve insufficiency of the ulnar collateral ligament (UCL) of the thumb. The chief difference between these two conditions is that Skier's thumb is generally considered to be an acute condition acquired after a fall or similar abduction injury to the metacarpophalangeal (MCP) joint of the thumb, whereas gamekeeper's thumb typically refers to a chronic condition which has developed as a result of repeated episodes of lower-grade hyperabduction over a period of time. Gamekeeper's thumb is more difficult to treat because the UCL has lengthened and become thinner as a result of repeated injury. It is moderately painful compared to similar injuries.

In addition to skiing, this injury (resulting from forced abduction or hyperextension of the proximal phalanx of the thumb) is seen in a wide variety of other athletic endeavors. The most common mechanism of injury appears to be when a person extends the arm in an attempt to block a fall. The stress resulting from falling onto an abducted thumb produces a valgus force on the MCP joint of the thumb, resulting in a sprain or tear of the UCL.

In a recent study, 49% of UCL disruptions of the thumb were caused by a fall onto an outstretched hand. Sports injuries accounted for most of the remaining injuries, with only 2.4% acquired as a result of skiing injuries.

The decisions involved in the repair of the Hill–Sachs lesion are complex. First, it is not repaired simply because of its existence, but because of its association with continuing symptoms and instability. This may be of greatest importance in the under-25-year-old and in the athlete involved in throwing activities. The Hill-Sachs role in continuing symptoms, in turn, may be related to its size and large lesions, particularly if involving greater than 20% of the articular surface, may impinge on the glenoid fossa (engage), promoting further episodes of instability or even dislocation. Also, it is a fracture, and associated bony lesions or fractures may coexist in the glenoid, such as the so-called bony Bankart lesion. Consequently, its operative treatment may include some form of bony augmentation, such as the Latarjet or similar procedure. Finally, there is no guarantee that associated non-bony lesions, such as a Bankart lesion, SLAP tear, or biceps tendon injury, may not be present and require intervention.

The Maisonneuve fracture is a spiral fracture of the proximal third of the fibula associated with a tear of the distal tibiofibular syndesmosis and the interosseous membrane. There is an associated fracture of the medial malleolus or rupture of the deep deltoid ligament. This type of injury can be difficult to detect.

The Maisonneuve fracture is similar to the Galeazzi fracture in the sense that there is an important ligamentous disruption in association with the fracture. The fracture is named after the surgeon Jules Germain François Maisonneuve.

An unhappy triad (or terrible triad, "horrible triangle", O'Donoghue's triad or a "blown knee") is an injury to the anterior cruciate ligament, medial collateral ligament, and medial meniscus. Analysis during the 1990s indicated that this 'classic' O'Donoghue triad is actually an unusual clinical entity among athletes with knee injuries. Some authors mistakenly believe that in this type of injury, acute tears of the medial meniscus always present with a concomitant lateral meniscus injury. However, the 1990 analysis showed that lateral meniscus tears are more common than medial meniscus tears in conjunction with sprains of the ACL.

Gamekeeper's thumb (also known as skier's thumb or UCL tear) is a type of injury to the ulnar collateral ligament (UCL) of the thumb. The UCL may be torn, damaged or in some cases avulsed from its insertion site into the proximal phalanx of the thumb in the vast majority (approximately 90%) of cases. This condition is commonly observed among gamekeepers and Scottish fowl hunters, as well as athletes (such as volleyballers). It also occurs among people who sustain a fall onto an outstretched hand, frequently skiers.

Though articular cartilage damage is not life-threatening, it does strongly affect one's quality of life. Articular cartilage damage is often the cause of severe pain, knee swelling, substantial reduction in mobility and severe restrictions to one's activities. Over the last decades, however, research has focused on regenerating damaged joints.

These regenerative procedures are believed to delay osteoarthritis of injuries on the articular cartilage of the knee, by slowing down the degeneration of the joint compared to untreated damage. According to Mithoefer "et al." (2006), these articular cartilage repair procedures offer the best results when the intervention takes place in the early stages of the cartilage damage.

A strain can occur as a result of improper body mechanics with any activity (e.g., contact sports, lifting heavy objects, overstretching) that can induce mechanical trauma or injury. Generally, the muscle or tendon overstretches and is placed under more physical stress than it can exert. Strains commonly result in a partial or complete tear of a tendon or muscle, or they can be severe in the form of a complete tendon rupture. The most common body location for strains to occur is in the foot, leg, or back.

- Acute strains are more closely associated with recent mechanical trauma or injury.

- Chronic strains typically result from repetitive movement of the muscles and tendons over a long period of time.

Degrees of Injury (as classified by the American College of Sports Medicine)

• First degree (mildest) – little tissue tearing; mild tenderness; pain with full range of motion.

• Second degree – torn muscle or tendon tissues; painful, limited motion; possibly some swelling or depression at the spot of the injury.

• Third degree (most severe) – limited or no movement; pain will be severe at first, but may be painless after the initial injury

In terms of overuse injuries a British study found that:

- 40 percent occurred in the fingers

- 16 percent in the shoulders

- 12 percent in the elbows

- 5 percent were the knees

- 5 percent back

- 4 percent wrists

One injury that tend to be very common among climbers is Carpal tunnel syndrome. It is found in about 25% of climbers.

Articular cartilage has a very limited capacity for self repair. Small damage does not repair itself and can often get worse over time. As cartilage is aneural and avascular (lack of nerve and blood supply, respectively), shallow damage often does not trigger pain.

When the damage increases and the chondral defect reaches the subchondral bone, the blood supply in the bone starts a healing process in the defect. Scar tissue made up of a type of cartilage called fibrocartilage is then formed. Although fibrocartilage is able to fill in articular cartilage defects, its structure is significantly different from that of hyaline cartilage; it is much denser and it doesn't withstand the demands of everyday activities as much as hyaline cartilage. It is therefore at a higher risk of breaking down.

Wang "et al."(2006) found that small articular cartilage defects can progress to osteoarthritis over time if left untreated. An articular cartilage defect that initially may be small still has the potential to have a physical and chemical "domino effect" on the surrounding "normal" articular cartilage.