Repetitive trauma

The first tissue engineering product to be approved targeted the treatment of burns and consisted of keratinocytes cultivated in vitro, which form a tissue that is later transplanted to the patient. Beyond this product, others are already being commercialized for a wide range of applications. Examples are Carticel (marketed by Genzyme), which consists of chondrocytes employed in the treatment of cartilaginous defects caused by acute or repetitive traumas Apligraf (Novartis), used in the treatment of venous ulcer and DACS SC (Dendreon), utilized for reconstitution of the immune system after chemotherapy. 

Repair of clinically significant, symptomatic, cartilaginous defects of the femoral condyle (medial, lateral or trochlear) caused by acute or repetitive trauma Imaging agent for colorectal cancer... 

Table 11.2. Timing of radiological changes in paediatric fractures. [Modified from O Connor and Cohen (1998)]. NB The evolution of fracture healing is more rapid in the young infant compared with the older child and is influenced by lack of immobilisation and repetitive trauma...

Pre-employment evaluation of workers serves the purpose of primary prevention against occupational skin disease. Screening prospective workers for an increased risk of developing occupational contact psoriasis, by looking for personal and familial psoriatic background and the physical markers of the disease, may be important in job placement. Workers with predisposition to psoriasis should be discouraged from holding jobs that expose them to risk of skin injury and repetitive trauma. 

As regards the location of the degenerative areas, the increased risk of certain anatomic sites for development of tendinosis has led to the concept of critical zones, in which several factors, such as aging, hypovascularization, and biomechanical effects in combination with repetitive trauma, play a specific causative role (Kainberger et al. 1997 Schepsis et al. 2002). In the Achilles tendon, for example, the predominant involvement of its middle third has been attributed to the fact that this is an area of low vas-... 

Chronic posterior ankle pain may also be related to bursal pathology, which may occur as an isolated disorder but is more often secondary to inflammatory disorders, such as rheumatoid arthritis and seronegative spondyloarthropathies, or repetitive trauma, usu-... 

Peripheral nerve injuries are caused by a variety of factors including acute trauma, chronic repetitive insults, and inheritable or acquired metabolic disorders (Ch. 36). As opposed to the CNS, which has traditionally been thought to be fixed, axonal injury in the PNS often results in some degree of spontaneous regeneration, although it... 

The prevalence and severity of OA increase with age. Potential risk factors include obesity, repetitive use through work or leisure activities, joint trauma, and heredity. 

The B-criterion, reexperiencing, involves persistent intrusive memories, sudden reminders, or flashbacks associated with the trauma. In children these symptoms may involve repetitive play reenacting traumatic themes, recurrent frightening dreams, or intense distress at reminders of the trauma. 

We will rely heavily on a literature review for this section (Aman, 1993). Self-injury may be defined as external trauma resulting from repetitive acts directed against oneself. Within residential institutions, the prevalence of self-injury is typically between 10% and 15%, whereas outside of institutions the prevalence is often reported as being between 1% and 2.5% (Aman, 1993). Factors associated with self-injury include se-... 

Recurrent and intrusive distressing recollections of the event including images, thoughts, or perceptions. Note In young children, repetitive play may occur in which themes or aspects of the trauma are expressed. 

Toxicity primarily involves the CNS and cardiovascular system. CNS effects include increased alertness, restlessness, decreased appetite, irritability, stereotyped repetitive behavior, and insomnia with low doses. With larger exposures confusion, panic reactions, aggressive behavior, hallucinations, seizures, delirium, coma, and death can occur. Intracranial bleeding can result from untreated hypertension. Trauma is common secondary to the changes in behavior and decreased judgment. Frequent use results in fatigue, paranoia, and depression. Cardiovascular effects include increased heart rate and blood pressure, chest pain, myocardial ischemia or... 

In addition to aberrant internal metabolism, external insult such as traumatic brain injury can increase the risk of AD [63-65]. The mechanisms by which head traiuna may augment the risk of AD is unknown. Repetitive head traiuna experienced by professional boxers may lead to punch drunk syndrome or dementia pugifistica later in fife [66]. This syndrome is characterized by progressive dementia and parkinsonism and the presence of senile plaques and neurofibrillary tangles [67,68]. Ap deposition has been detected in the brains of victims of even a single head injury [69]. In preclinical models head trauma can exacerbate the formation of plaques or tangles, induce neu-... 

Brief shocklike muscular contractions of the face, trunk, and extremities are known as myoclonicjerks. They may be isolated events or rapidly repetitive. A sudden loss of muscle tone is known as an atonic seizure. This may be described as a head drop, the dropping of a limb, or a slumping to the ground. These patients often wear protective headware to prevent trauma. 

Other task considerations dealing with the content of the task that ate related to the physical requirements include the pace or rate of work, the amount of repetition in task activities, and work pressure due to production demands. Task activities that are highly repetitive and paced by machinety rather than by the employee tend to be stressful. Such conditions also diminish an employee s attention to hazards and the capability to respond to a hazard due to boredom. These conditions may produce cumulative trauma disorders to the musculoskeletal system when the task activity cycle time is short and constant. Tasks with relatively low workload and energy expenditure can be very hazardous due to the high frequency of muscle and joint motions and boredom, which leads to employee inattention to hazards. 

The three main occupational risk factors are repetition/duration, joint deviation, and force. Vibration is also an important risk factor. Nonoccupationeil risk factors can be from trauma outside work or a nonperfect body. The lack of perfection can be ematomical (werik back muscles or werik arm due to an injury) or physiological (diabetes, insufficient hormones). 

In general, a job is considered repetitive if the basic (fundamental) cycle time is less than 30 sec (for hand/wrist motions) and severd minutes (for back/shoulder motions). However, if the job is only done for a short time (say, 15 min/shift), there is relatively low risk of cumulative trauma due to the short duration. Consider short duration as <1 hr/shift, moderate as 1 to 2 hr, and long as >2 hr. Thus, repetition really concerns the repetitions/shift. Duration also assumes weeks, months, and years of repeated activity, not just a couple of days. 

Human factors are also important in rehabilitation, where various aids for the disabled must be sized correctly, be versatile enough to accommodate special needs, be acceptable to the human user, and be socially acceptable to others. Without proper incorporation of human factors, health problems such as eyestrain, mental stress, and physical injury can result. Cumulative trauma disorder (work-related musculoskeletal disorder) comes about when working repetitively with tools under awkward conditions. Carpel tunnel syndrome is one form of this. 

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