People who have had a concussion seem more susceptible to another one, particularly if the new injury occurs before symptoms from the previous concussion have completely gone away. It is also a negative process if smaller impacts cause the same symptom severity. Repeated concussions may increase a person's risk in later life for dementia, Parkinson's disease, and depression.

MTBI has a mortality rate of almost zero. The symptoms of most concussions resolve within weeks, but problems may persist. These are seldom permanent, and outcome is usually excellent. The overall prognosis for recovery may be influenced by a variety of factors that include age at the time of injury, intellectual abilities, family environment, social support system, occupational status, coping strategies, and financial circumstances. People over age 55 may take longer to heal from MTBI or may heal incompletely. Similarly, factors such as a previous head injury or a coexisting medical condition have been found to predict longer-lasting post-concussion symptoms. Other factors that may lengthen recovery time after MTBI include psychological problems such as substance abuse or clinical depression, poor health before the injury or additional injuries sustained during it, and life stress. Longer periods of amnesia or loss of consciousness immediately after the injury may indicate longer recovery times from residual symptoms. For unknown reasons, having had one concussion significantly increases a person's risk of having another. Having previously sustained a sports concussion has been found to be a strong factor increasing the likelihood of a concussion in the future. Other strong factors include participation in a contact sport and body mass size. The prognosis may differ between concussed adults and children; little research has been done on concussion in the pediatric population, but concern exists that severe concussions could interfere with brain development in children.

A 2009 study found that individuals with a history of concussions might demonstrate a decline in both physical and mental performance for longer than 30 years. Compared to their peers with no history of brain trauma, sufferers of concussion exhibited effects including loss of episodic memory and reduced muscle speed.

Cumulative effects of concussions are poorly understood, especially the effects on children. The severity of concussions and their symptoms may worsen with successive injuries, even if a subsequent injury occurs months or years after an initial one. Symptoms may be more severe and changes in neurophysiology can occur with the third and subsequent concussions. Studies have had conflicting findings on whether athletes have longer recovery times after repeat concussions and whether cumulative effects such as impairment in cognition and memory occur.

Cumulative effects may include psychiatric disorders and loss of long-term memory. For example, the risk of developing clinical depression has been found to be significantly greater for retired American football players with a history of three or more concussions than for those with no concussion history. Three or more concussions is also associated with a fivefold greater chance of developing Alzheimer's disease earlier and a threefold greater chance of developing memory deficits.

Many closed-head injuries can be prevented by proper use of safety equipment during dangerous activities. Common safety features that can reduce the likelihood of experiencing a brain injury include helmets, hard hats, car seats, and safety belts. Another safety precaution that can decrease a person's risk for brain injury is "not" to drink and drive or allow oneself to be driven by a person who has been drinking or who is otherwise impaired.

Helmets can be used to decrease closed-head injuries acquired during athletic activities, and are considered necessary for sports such as American "tackle" football, where frequent head impacts are a normal part of the game. However, recent studies have questioned the effectiveness of even American football helmets, where the assumed protection of helmets promotes far more head impacts, a behavior known as risk compensation. The net result seems to have been an increase, not decrease, in TBI. The similar sports of Australian-rules football and rugby are always played helmetless, and see far fewer traumatic brain injuries. (See Australian rules football injuries.)

Bicycle helmets are perhaps the most promoted variety of helmet, based on the assumption that cycling without a helmet is a dangerous activity, with a large risk of serious brain injury. However, available data clearly shows that to be false. Cycling (with approximately 700 American fatalities per year from all medical causes) is a very minor source of fatal traumatic brain injury, whose American total is approximately 52,000 per year. Similarly, bicycling causes only 3% of America's non-fatal TBI.

Still, bicycle-helmet promotion campaigns are common, and many U.S jurisdictions have enacted mandatory bicycle-helmet laws for children. A few such jurisdictions, a few Canadian provinces, plus Australia and New Zealand mandate bicycle helmets even for adults. A bicycle-helmet educational campaign directed toward children claimed an increase in helmet use from 5.5% to 40.2% leading to a claimed decrease in bicycle-related head injuries by nearly 67%. However, other sources have shown that bicycle-helmet promotion reduces cycling, often with no per-cyclist reduction in TBI.

Estimates of bicycle-helmet use by American adults vary. One study found that only 25-30% of American adults wear helmets while riding bicycles, despite decades of promotion and despite sport cyclists' adoption of helmets as part of their uniform. It would appear that the typical American adult correctly recognizes ordinary cycling as a very minor risk.

Following the commercial (as opposed to public-health) success of bicycle helmets, there have been successful attempts to promote the sale of ski helmets. Again, results have been less than impressive, with great increases in helmet use yielding no reduction in fatalities, and with most injury reduction confined to lacerations, contusions, and minor concussions, as opposed to more serious head injuries.

There have been rare campaigns for motoring helmets. Unfortunately, just as people greatly overestimate the TBI danger of bicycling, they greatly underestimate the risk of motoring, which remains the largest source of TBI in the developed world, despite the protective effects of seatbelts and airbags.

Head injuries in sports of any level (junior, amateur, professional) are the most dangerous and sickening kind of injuries that can occur in sport, and are becoming more common in Australian sport. Concussions are the most common side effect of a head injury and are defined as "temporary unconsciousness or confusion and other symptoms caused by a blow to the head." A concussion also falls under the category of Traumatic Brain Injury (TBI). Especially in contact sports like Australian rules football and Rugby issues with concussions are prevalent, and methods to deal with, prevent and treat concussions are continuously being updated and researched to deal with the issue. Concussions pose a serious threat to the patients’ mental and physical health, as well as their playing career, and can result in lasting brain damage especially if left untreated. The signs that a player may have a concussion are: loss of consciousness or non-responsiveness, balance problems (unsteadiness on feet, poor co-ordination), a dazed, blank or vacant look and/or confusion and unawareness of their surroundings. Of course the signs are relevant only after the player experiences a blow to the head.

Concussions in England's professional rugby union are the most common injury gained. Concussion can occur where an individual experiences a minor injury to the head. Commonly occurring in high contact sporting activities; American football, boxing, and rugby. It can also occur in recreational activities like horse riding, jumping, cycling, and skiing. The reason being that it doesn't have to be something to strike you in the proximity of your brain, but can also be caused by rapid change of movement, giving the skull not enough time to move with your body, causing your brain to press against your skull. With rugby being such a contact and fast moving sport, it is no wonder why there is concussion and other head injuries occurring. With the development of equipment and training methods, these will help benefit the players on the field know what could happen and how they can help with preventing it.

Concussions, a type of traumatic brain injury, are a frequent concern for those playing sports, from children and teenagers to professional athletes. Repeated concussions are a known cause of various neurological disorders, most notably chronic traumatic encephalopathy (CTE), which in professional athletes has led to premature retirement, erratic behavior and even suicide. Because concussions cannot be seen on X-rays or CT scans, attempts to prevent concussions have been difficult.

A concussion is defined as a complex pathophysiological process affecting the brain, induced by traumatic forces. Concussion may be caused either by a direct blow to the head, face, neck or elsewhere on the body with an "impulsive" force transmitted to the head. Also, you don't have to pass out when you get a concussion (Aubry et al., 2001).

The dangers of repeated concussions have long been known for boxers and wrestlers; a form of CTE common in these two sports, dementia pugilistica (DP), was first described in 1928. An awareness of the risks of concussions in other sports began to grow in the 1990s, and especially in the mid-2000s, in both the medical and the professional sports communities, as a result of studies of the brains of prematurely deceased American football players, who showed extremely high incidences of CTE (see concussions in American football).

As of 2012, the four major professional sports leagues in the United States and Canada have concussion policies. Sports-related concussions are generally analyzed by athletic training or medical staff on the sidelines using an evaluation tool for cognitive function known as the Sport Concussion Assessment Tool (SCAT), a symptom severity checklist, and a balance test.

Concussion symptoms can last for an undetermined amount of time depending on the player and the severity of the concussion. A concussion will affect the way a person's brain works.

There is the potential of post-concussion syndrome, post-concussion syndrome is defined as a set of symptoms that may continue after a concussion is sustained. Post-concussion symptoms can be classified into physical, cognitive, emotional, and sleep symptoms. Physical symptoms include a headache, nausea, and vomiting. Athletes may experience cognitive symptoms that include speaking slowly, difficulty remembering and concentrating. Emotional and sleep symptoms include irritability, sadness, drowsiness, and trouble falling asleep.

Along with the classification of post-concussion symptoms, the symptoms can also be described as immediate and delayed. The immediate symptoms are experienced immediately after a concussion such as: memory loss, disorientation, and poor balance. Delayed symptoms are experienced in the later stages and include sleeping disorders and behavioral changes. Both immediate and delayed symptoms can continue for long periods of time and have a negative impact on recovery. According to research, 20-25% of individuals who have sustained a concussion experienced chronic, delayed symptoms.

Playing through concussion makes people more vulnerable to getting hit again, and that is why most sports have test that trainers will perform to prevent getting hit a second time. A second blow can cause a rare condition known as second-impact syndrome, which can result in severe injury or death. Second-impact syndrome is when an athlete suffers a second head injury before the brain has adequate time to heal in between concussions.

Repeated concussions have been linked to a variety of neurological disorders among athletes, including CTE, Alzheimer's Disease, Parkinsonism and Amyotrophic lateral sclerosis (ALS).

Concussions and other types of repetitive play-related head blows in American football have been shown to be the cause of chronic traumatic encephalopathy (CTE), which has led to player suicides and other debilitating symptoms after retirement, including memory loss, depression, anxiety, headaches, and also sleep disturbances.

The list of ex-NFL players that have either been diagnosed "post-mortem" with CTE or have reported symptoms of CTE continues to grow.

There are several different types of treatment available to those who have suffered a closed-head injury. The treatment type chosen can depend on several factors including the type and severity of injury as well as the effects that injury has on the patient.

The course of treatment differs for each patient and can include several types of treatment, depending on the patient’s specific needs.

Early treatment is vital to recovering lost motor function after an injury, but cognitive abilities can be recovered regardless of time past since injury.

Once taken off the field of play due to possible concussion, being unconscious, or showing the symptoms post game, getting medical advice as soon as possible is recommended. At the hospital or medical practice, the player will be under observation, if they are experiencing a headache, mild pain killers will be given. The medical professional will request that no food or drink is to be consumed until advised. They will then assess whether the player needs an x-ray, to check for any possible cervical vertebrae damage, or a computerised axial tomography (CT Scan) to check for any brain or cranium damage. With a mild head injury being sent home to take care and doing activities slower than usual, and maintaining painkillers. If symptoms of concussion don't disappear in the average of seven to ten days, then seek medical advice again as injury could be worse. In post-concussion syndrome, symptoms do not resolve for weeks, months, or years after a concussion, and may occasionally be permanent. About 10% to 20% of people have post concussion syndrome for more than a month.

The occurrence of concussion in children during sport is significantly more likely compared to other levels of athletes. Roughly 20% of children playing sport are diagnosed with concussion. Despite the lower level of impact compared to the professional or amateur levels, children's neck muscles are quite weak and most lack the awareness and skill level to cushion or prepare themselves for a blow leading to a high concussion rate. The guidelines and protocols for a child suffering a concussion are basically the same as if an adult received one.

For a child diagnosed with a concussion, the real issue is returning to school rather than the sporting field, as a concussion can affect a child's learning ability. A medical clearance is required before a return to school is possible and parents are recommended to properly manage their child through the first 72 hours after experiencing a concussion.

Concussions are proven to cause loss of brain function. This can lead to physical and emotional symptoms such as attention disorders, depression, headaches, nausea, and amnesia. These symptoms can last for days or week and even after the symptoms have gone, the brain still won't be completely normal. Players with multiple concussions can have drastically worsened symptoms and exponentially increased recovery time.

Researchers at UCLA have, for the first time, used a brain-imaging tool to identify a certain protein found in five retired NFL players. The presence and accumulation of tau proteins found in the five living players, are associated with Alzheimer's disease. Previously, this type of exam could only be performed with an autopsy. Scientists at UCLA created a chemical marker that binds to the abnormal proteins and they are able to view this with Positron Emission Tomography (PET) scan. Researcher at UCLA, Gary Small explains, "Providing a non-invasive method for early detection is a critical first step in developing interventions to prevent symptom onset and progression in CTE".

Falling and colliding with other people in a contact sport can also cause this fracture. Falling causes the weight of the body to force hyperextension. In full-contact sports such as American football and Rugby, diving for the ball can lead a player to land on his head, forcing the neck into hyperextension. The further piling of players on top of an injured player adds more weight and can lead to further occurrences of this fracture.

Most commonly this can occur during a car accident. A person involved in a car crash, especially with no seat belt, can slam their chin against the steering wheel, dashboard, or windshield, causing the hyperextension to occur.

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease found in people who have had multiple head injuries. Symptoms may include behavioral problems, mood problems, and problems with thinking. This typically does not begin until years after the injuries. It often gets worse over time and can result in dementia. It is unclear if the risk of suicide is altered.

Most documented cases have occurred in athletes involved in contact sports such as football, wrestling, ice hockey, and soccer. Other risk factors include being in the military, prior domestic violence, and repeated banging of the head. The exact amount of trauma required for the condition to occur is unknown. Definitive diagnosis can only occur at autopsy. It is a form of tauopathy.

As of 2017 there is no specific treatment. Rates of disease have been found to be about 30% among those with a history of multiple head injuries. Population rates, however, are unclear. Research into brain damage as a result of repeated head injuries began in the 1920s, at which time the condition was known as "punch drunk". Changing the rules in some sports has been discussed as a means of prevention.

A stinger is an injury that is caused by restriction of the nerve supply to the upper extremity via the brachial plexus. The brachial plexus is formed by the anterior rami of the nerves at the 5th cervical level of the spinal cord all the way to the nerves at the 1st thoracic level of the spinal cord. The brachial plexus innervates the upper extremity as well as some muscles in the neck and shoulder. Damage to the brachial plexus can occur when the nerves are stretched too far from the head and neck; specifically the upper trunk of the plexus –nerve roots at the 5th and 6th cervical level –are primarily affected. The upper trunk provides part of the nerve to supply to the upper extremity via the Musculocutaneous, Axillary, Radial and Median nerves. It is for this reason that stingers do not affect both arms simultaneously, however it is possible for both arms to accrue injuries. Repeated nerve trauma can cause recurring stingers, chronic pain, and muscle weakness, while recovery can take weeks to months in severe cases.

Stingers are best diagnosed by a medical professional. This person will assess the athlete's pain, range of head and neck motion, arm numbness, and muscle strength. Often, the affected athlete is allowed to return to play within a short time, but persistent symptoms will result in removal. Athletes are also advised to receive

regular evaluations until symptoms have ceased. If they have not after two weeks, or increase, additional tests such as magnetic resonance imaging (MRI) can be performed to detect a more serious injury, such as a herniated disc.

The order of treatments applied depends on whether the athlete's main complaint is pain or weakness. Both can be treated with an analgesic, anti-inflammatory medication, ice and heat, restriction of movement, and if necessary, cervical collar or traction. Surgery is only necessary in the most severe cases.

Considerable force is needed to cause a cervical fracture. Vehicle collisions and falls are common causes. A severe, sudden twist to the neck or a severe blow to the head or neck area can cause a cervical fracture.

Sports that involve violent physical contact carry a risk of cervical fracture, including American football, Goalkeeper (association football), ice hockey, rugby, and wrestling. Spearing an opponent in football or rugby, for instance, can cause a broken neck. Cervical fractures may also be seen in some non-contact sports, such as gymnastics, skiing, diving, surfing, powerlifting, equestrianism, mountain biking, and motor racing.

Certain penetrating neck injuries can also cause cervical fracture which can also cause internal bleeding among other complications.

Hanging also incurs a cervical fracture.

Symptoms of CTE, which occur in four stages, generally appear 8 to 10 years after an athlete experiences repetitive mild traumatic brain injury.

First-stage symptoms include attention deficit hyperactivity disorder as well as confusion, disorientation, dizziness, and headaches. Second-stage symptoms include memory loss, social instability, impulsive behavior, and poor judgment. Third and fourth stages include progressive dementia, movement disorders, hypomimia, speech impediments, sensory processing disorder, tremors, vertigo, deafness, depression and suicidality.

Additional symptoms include dysarthria, dysphagia, cognitive disorder such as amnesia, and ocular abnormalities, such as ptosis.

The condition manifests as dementia, or declining mental ability, problems with memory, dizzy spells or lack of balance to the point of not being able to walk under one's own power for a short time and/or Parkinsonism, or tremors and lack of coordination. It can also cause speech problems and an unsteady gait. Patients with DP may be prone to inappropriate or explosive behavior and may display pathological jealousy or paranoia.

Complete immobilization of the head and neck should be done as early as possible and before moving the patient. Immobilization should remain in place until movement of the head and neck is proven safe. "In the presence of severe head trauma, cervical fracture must be presumed until ruled out." Immobilization is imperative to minimize or prevent further spinal cord injury. The only exceptions are when there is imminent danger from an external cause, such as becoming trapped in a burning building.

Non-steroidal anti-inflammatory medications (NSAIDs), such as aspirin or ibuprofen, are contraindicated because they interfere with bone healing. Tylenol (acetaminophen) is a better option. Patients with cervical fractures will likely be prescribed medication for pain control.

In the long term, physical therapy will be given to build strength in the muscles of the neck to increase stability and better protect the cervical spine.

Collars, traction and surgery can be used to immobilize and stabilize the neck after a cervical fracture.

Clavicle fractures occur at 30–64 cases per 100,000 a year and are responsible for 2.6–5.0% of all fractures. This type of fracture occurs more often in males. About half of all clavicle fractures occur in children under the age of seven and is the most common pediatric fracture. Clavicle fractures involve roughly 5% of all fractures seen in hospital emergency admissions. Clavicles are the most commonly broken bone in the human body.

In children, the results of early treatment are always good, typically normal or nearly so. If diagnosis is delayed, reconstructive surgery is needed and complications are much more common and results poorer. In adults, the healing is slower and results usually not as good.

Complications of ORIF surgery for Monteggia fractures can include non-union, malunion, nerve palsy and damage, muscle damage, arthritis, tendonitis, infection, stiffness and loss of range of motion, compartment syndrome, audible popping or snapping, deformity, and chronic pain associated with surgical hardware such as pins, screws, and plates. Several surgeries may be needed to correct this type of fracture as it is almost always a very complex fracture that requires a skilled orthopedic surgeon, usually a 'specialist', familiar with this type of injury.

Monteggia fractures may be managed conservatively in children with closed reduction (resetting and casting), but due to high risk of displacement causing malunion, open reduction internal fixation is typically performed.

Osteosynthesis (open reduction and internal fixation) of the ulnar shaft is considered the standard of care in adults. It promotes stability of the radial head dislocation and allows very early mobilisation to prevent stiffness. The elbow joint is particularly susceptible to loss of motion.

In children, whose bones are still developing, there are risks of either a growth plate injury or a greenstick fracture.

- A greenstick fracture occurs due to mechanical failure on the tension side. That is, since the bone is not so brittle as it would be in an adult, it does not completely fracture, but rather exhibits bowing without complete disruption of the bone's cortex in the surface opposite the applied force.

- Growth plate injuries, as in Salter-Harris fractures, require careful treatment and accurate reduction to make sure that the bone continues to grow normally.

- Plastic deformation of the bone, in which the bone permanently bends, but does not break, also is possible in children. These injuries may require an osteotomy (bone cut) to realign the bone if it is fixed and cannot be realigned by closed methods.

- Certain fractures mainly occur in children, including fracture of the clavicle and supracondylar fracture of the humerus.

Smokers generally have lower bone density than non-smokers, so have a much higher risk of fractures. There also is evidence that smoking delays bone healing.