Workers in certain fields are at risk of repetitive strains. Most occupational injuries are musculoskeletal disorders, and many of these are caused by cumulative trauma rather than a single event. Miners and poultry workers, for example, must make repeated motions which can cause tendon, muscular, and skeletal injuries.

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.

Back strain occurs more in women than men and is more common after pregnancy. Lean people, those standing for long hours and those doing sedentary work in bad posture are prone to back strain. Back strain is also more common in people with excessive curving of the back, weak muscles (as in muscular dystrophies) and tight thigh muscles. Sportspersons who play sports involving lifting heavy weights, pushing and pulling are also prone to back strain.

A side strain is a muscle strain caused by tearing of the transversalis fascia or the internal oblique muscle. When this occurs, stretching the muscle will be severely painful, making it difficult to move the arm, and the strain may later be marked by swelling or bruising.

The strain usually occurs due to the internal oblique muscle contracting suddenly from a stretched position. It may happen suddenly, or over time from regular repetitive activity. It is common in cricket players, and occurs on the opposite side of the arm that is used for bowling. The injury has also been reported in rowing, baseball and ice hockey. The preferred treatment for a side strain is regular rest and inactivity on the affected muscle. With appropriate rest, regular activity on the muscle can occur between 4 and 6 weeks, though it may take longer.

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.

The diagnosis of mild back strain can be made with a medical history and physical examination. In case of more severe strains, an X-ray should be taken to rule out fracture and disc herniation. Back sprain is treated using analgesics such as ibuprofen, rest and use of ice packs. The patient can resume activities 24-48 hours after pain and swelling is reduced. It is not recommended to have prolonged immobilization or bed rest. If the pain does not subside in two weeks, additional treatment may be required.

Prevention of back strain is possible by adopting proper body mechanics while sitting, standing and lifting. Cessation of smoking, maintaining a healthy diet, exercise and normal weight is also good for preventing back strain.

Repetitive strain injury (RSI) and associative trauma orders are umbrella terms used to refer to several discrete conditions that can be associated with repetitive tasks, forceful exertions, vibrations, mechanical compression, or sustained/awkward positions. Examples of conditions that may sometimes be attributed to such causes include edema, tendinosis (or less often tendinitis), carpal tunnel syndrome, cubital tunnel syndrome, De Quervain syndrome, thoracic outlet syndrome, intersection syndrome, golfer's elbow (medial epicondylitis), tennis elbow (lateral epicondylitis), trigger finger (so-called stenosing tenosynovitis), radial tunnel syndrome, ulnar tunnel syndrome, and focal dystonia.

Since the 1970s there has been a worldwide increase in RSIs of the arms, hands, neck, and shoulder attributed to the widespread use of typewriters/computers in the workplace that require long periods of repetitive motions in a fixed posture.

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.

According to the International Classification of Diseases, 9th Revision, Clinical Modification, ICD-9-CM, in 2008 the U.S. listed the diagonsis code for UCL injury as 841.1: Sprain ulnar collateral ligament. There were a total of 336 discharges of UCL injuries. Within the total discharges, separated by age groups: 18- to 44-year-olds; 165 people (49.17%). 45- to 64-year-olds; 91 (27.08%). 65- to 84-year-olds, 65 (19.35%) it shows that the ulnar collateral ligament injuries were more commonly found in men than women. There were 213 men compared to 123 women with ulnar collateral ligament injury. Most of these injuries were also paid through private insurance (170: 50.63%) and Medicare (70: 20.85%). The average estimated cost for the surgery also known as Tommy John surgery is $21,563.

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

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

About 16% of deliveries where shoulder dystocia occurs will have conventional risk factors.

There are well-recognized risk factors, such as diabetes, fetal macrosomia, and maternal obesity, but it is often difficult to predict, despite recognised risk factors. Despite appropriate obstetric management, fetal injury (such as brachial plexus injury) or even fetal death can be a complication of this obstetric emergency.

Risk factors:

- Age >35

- Short in stature

- Small or abnormal pelvis

- More than 42 weeks gestation

- Estimated fetal weight > 4500g

- Maternal diabetes (2-4 fold increase in risk)

Factors which increase the risk/are warning signs:

- the need for oxytocics

- a prolonged first or second stage of labour

- turtle sign

- head bobbing in the second stage

- failure to restitute

- No shoulder rotation or descent

- Instrumental delivery

Recurrence rates are relatively high (if you had shoulder dystocia in a previous delivery the risk is now 10% higher than in the general population).

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.

Although the definition is imprecise, it occurs in approximately 0.3-1% of vaginal births.

Several risk factors of CMC OA of the thumb are known. Each of these risk factors does not cause CMC OA by itself, but acts as a predisposing factor influencing the process of OA in some way. Risk factors include: female gender, suffering from obesity, repetitive heavy manual labor, familial predisposition and hormonal changes, such as menopause.

CMC OA is the most common form of OA affecting the hand. Dahaghin et al. showed that about 15% of women and 7% of men between 50 and 60 years of age suffer from CMC OA of the thumb. However, in about 65% of people older than 55 years, radiologic evidence of OA was present without any symptoms. Armstrong et al. reported a prevalence of 33% in postmenopausal women, of which one third was symptomatic, compared to 11% in men older than 55 years. This shows CMC OA of the thumb is significantly more prevalent in women, especially in postmenopausal women, compared to men.

The UCL is important because it stabilizes the elbow from being abducted. If intense or repeated bouts of valgus stress occur on the UCL, injury will most likely transpire. Damage to the ulnar collateral ligament is common among baseball pitchers and javelin throwers because the throwing motion is similar. Physicians believe repetitive movements, especially pitching in baseball, cause adolescents' UCL injuries. Furthermore, physicians have stated that if an adolescent throws over 85 throws for 8 months or more in a year, or throw when exhausted, the adolescent has a significantly higher risk of succumbing to a UCL surgery. Gridiron football, racquet sports, ice hockey and water polo players have also been treated for damage to the ulnar collateral ligament. Specific overhead movements like those that occur during baseball pitching, tennis serving or volleyball spiking increase the risk of UCL injury. During the cocking phase of pitching, the shoulder is horizontally abducted, externally rotated and the elbow is flexed. There is slight stress on the UCL in this position but it increases when the shoulder is further externally rotated. The greater the stress the more the UCL is stretched causing strain. During the overhead throwing motion, valgus stress on the medial elbow occurs during arm cocking and acceleration. The initiation of valgus stress occurs at the conclusion of the arm-cocking phase. In the transitional moment from arm cocking to arm acceleration, the shoulder vigorously rotates internally, the forearm is in near full supination, and the elbow flexes from 90° to approximately 125°. From late cocking to ball release, the elbow rapidly extends from approximately 125° to 25° at ball release. This causes tremendous valgus stress and tensile strain on the UCL. Injuries to the ulnar collateral ligament are believed to result from poor throwing mechanics, overuse, high throwing velocities, and throwing certain types of pitches, such as curveballs. Poor mechanics along with high repetition of these overhead movements can cause irritation, micro-tears or ruptures of the UCL. Injuries to the Ulnar Collateral Ligament in baseball players are rarely due to one-time, traumatic events. Rather, they are more often due to small chronic tears that accumulate over time.

A hip pointer is a contusion on the pelvis caused by a direct blow or a bad fall at an iliac crest and / or hip bone and a bruise of the abdominal muscles (transverse and oblique abdominal muscles). Surrounding structures such as the tensor fasciae latae and the greater trochanter may also be affected. The injury results from the crushing of soft tissue between a hard object and the iliac crest. Contact sports are a common cause of this type of injury, most often in football and hockey in general due to improper equipment and placement. The direct impact can cause an avulsion fracture where a portion of bone is removed by a muscle. The pain is due to the cluneal nerve that runs right along the iliac crest, which makes this a very debilitating injury. This pain can be felt when walking, laughing, coughing or even breathing deeply.

A hip pointer bruise usually causes bleeding into the hip abductor muscles, which move legs sideways, away from the midline of the body. This bleeding into muscle tissue creates swelling and makes leg movement painful. The hematoma that occurs can potentially build on the femoral nerve or lateral cutaneous of the femur. This injury usually lasts from one to six weeks, depending on the damage. In most cases, patients recover completely. A full assessment should be undertaken to rule out the possibility of damage to abdominal organs.

Tendonitis is a very common, but misleading term. By definition, the suffix "-itis" means "inflammation of". Inflammation is the body's local response to tissue damage which involves red blood cells, white blood cells, blood proteins with dilation of blood vessels around the site of injury. Tendons are relatively avascular.

Corticosteroids are drugs that reduce inflammation. Corticosteroids can be useful to relieve chronic tendinopathy pain, improve function, and reduce swelling in the short term. However, there is a greater risk of long-term recurrence. They are typically injected along with a small amount of a numbing drug called lidocaine. Research shows that tendons are weaker following corticosteroid injections. Tendinitis is still a very common diagnosis, though research increasingly documents that what is thought to be tendinitis is usually tendinosis.

Rest, Ice, Compression and Elevation (RICE) are standard treatments in the first 48 hours of an injury to the hip pointer. After 48 hours, patients can begin gently stretching, strengthening exercises, flexibility and coordination. For the first 7–10 days, patients can take anti-inflammatories such as ibuprofen and apply ice. Since this injury is very painful, recovery is usually very slow. When the person is without pain, sports massage and range-of-motion activities may reduce tension and swelling and prevent scar tissue buildup. Furthermore, an injection of corticosteroids into the affected area may reduce symptoms in the short term and accelerate rehabilitation. Operative treatment is rarely indicated and is reserved for patients suffering from significant displacement or fractures of the bones.

To prevent hip pointer, the equipment must be adequate in the sport and be well positioned and good size. It should also maintain excellent flexibility, strength and endurance of the hip, pelvis and lower back muscles.

The most common causes of myalgia by injury are: sprains and strains.

Athletic pubalgia, also called sports hernia, hockey hernia, hockey groin, Gilmore's Groin, or groin disruption is a medical condition of the pubic joint affecting athletes.

It is a syndrome characterized by chronic groin pain in athletes and a dilated superficial ring of the inguinal canal. Football and ice hockey players are affected most frequently, and both recreational and professional athletes may be affected.

A multitude of conditions may lead to the development of torticollis including: muscular fibrosis, congenital spine abnormalities, or toxic or traumatic brain injury.

A rough categorization discerns between congenital torticollis and acquired torticollis.

Other categories include:

- Osseous

- Traumatic

- CNS/PNS

- Ocular

- Non-muscular soft tissue

- Spasmodic

- Drug induced

Most cases of back pain are related to issues in human musculoskeletal system and are not related to severe diseases. Musculoskeletal problems also called mechanical because many of them linked to vertebrae physical motions. Back pain itself is not considered a diagnosis, but rather a symptom of underlying (in most cases musculoskeletal) problems.

following:

- Vertebrae misalignment, which can cause nerve interference (also called subluxation), muscle tension, or muscle spasm

- Strained muscles

- Sprained ligaments

- Ruptured disks, which also called "slipped", or herniated disks

- Degenerative discs (lose their cushioning ability). The degeneration usually caused by repetitive strain, or injury, or aging.

- Irritated joints

Overuse of a muscle is using it too much, too soon and/or too often. Examples are:

- Repetitive strain injury.