Postural strain injuries
In a relaxed state, muscles do not require much blood, and the supply of blood matches the muscle’s demands. When the muscles are involved in rhythmic contractions, such as during walking, running or cycling, the blood circulation to the muscles increases and matches the increased demands of the muscles (unless the activity is very intense). When a muscle is contracted for a prolonged duration, the blood supply to the muscle is restricted due to continuous compression of the blood vessels by the muscle. At the same time, the muscle’s requirement for oxygen has increased due to the contraction, so the blood supply to the muscles is not matching the muscles demands.

When this chronic, static muscle contraction occurs, your body responds by sending cells to the area that will lay down fibrous connective tissue within the muscle to help re-enforce and support the muscle. Over a long period of time, the muscle slowly becomes weaker, more ”leathery”, and painful knots or trigger points will develop in the muscle.

The most common cause of static muscle contraction is poor posture. Poor posture can occur while standing, sitting, sleeping, playing sports, working, or doing hobbies. The most effective approach is prevention, which can be addressed by the individual or the activity

Prevention of postural strain

Individual interventions may include:

• Postural education for sitting, standing and sleeping
• Stretching and strengthening exercises
• Nutritional advice
• Advice on technique and biomechanics of the activity.

Activity interventions may include:

• Job analysis and ergonomic modifications to the activity

Clinical Management of postural strain

If this condition already exists and all attempts to self manage the condition fail to relieve the pain or stiffness, it is time to get help in managing the problem. Assuming that all of the self-management approaches are being addressed, the clinical management of chronic postural strains may involve the following and usually in this order:

• Restore the muscles to their normal state: This may involve Active Release Technique® and massage therapy to eliminate any scar tissue, physical modalities such as ultrasound or electrical modalities, mobilization and assisted stretching techniques, joint manipulation, nutrition, or acupuncture.
• Eliminate any compensation patterns: Your body will adapt to the way you use it. If chronic postures have been adopted for a period of time, or if pain has been present for a prolonged period, the body has created compensation patterns to the conditions. When the pain or posture has been corrected, your body may still be using these compensation patterns. They may include asymmetrical movement patterns such as limping, or postural habits such as slouching. Before any stabilization or strengthening can begin, these patterns must be eliminated or they will be perpetuated and lead to future problems.
• Stabilize the affected areas: The fine-tuning of motion in most joints of the body is controlled by smaller “stabilizing” muscles. If these muscles are injured or dysfunctional, then the joint will not move properly when the larger “force generating” muscles contract. If this occurs, then the joint and other tissues (tendons and ligaments) are stressed. This can lead to chronic dysfunction and repeated injury. Once the tissues have been returned to a normal state, then these small stabilizing muscles must be retrained to function properly. Exercises that train these muscles include stability exercises such as those performed on an exercise ball, wobble board, or any other device that challenges balance. The joint stabilizing muscles must be retrained before any strength exercises are performed to ensure that the joints are stable and will not be re-injured.
• Strengthen the affected areas: The final stage of rehabilitation is strengthening the larger “force generating” muscles through resistance training programs. These programs may take advantage of weights, elastic tubing, lifting body weight, or any other program that will fit into the individuals goals, lifestyle and resources.

Repetitive strain injuries are almost twice as common as all other types of workplace injuries and illness. These claims alone account for 60 percent of all the WMSD claims. There are other terms associated with repeated physical exertions including: musculoskeletal disorder, occupational musculoskeletal disorder, repetitive stress or strain disorder or syndrome, repetitive motion syndrome, overuse syndrome, and work-related disorder.

RSI’s occur due to small, but additive tissue damage sustained through performance of repetitive tasks. They often develop in the absence of acute injury and results in chronic localized pain and dysfunction with or without objective physical changes (such as swelling).

What are the risk factors in developing RSI’s?

The three primary physical risk factors that contribute to the development of RSI’s are:

• Force: The muscular force that is required by the worker to complete the task.
• Exposure: This includes the frequency with which the task must be performed, the duration of each task, the duration of the rest between tasks, and the duration of the work day.
• Posture: The postures that must be adopted by the worker during the execution of the task. The farther a workers posture is from neutral, the higher the risk of injury.

If only one risk factor is present, the risk of injury is low. As more risk factors are added to the task, the risk of an RSI occurring increases.

In addition to the primary risk factors, there are many secondary risk factors that can increase the jobs risk of RSI. These include:

• Vibration
• Lighting
• Temperature
• Noise
• Personal protective equipment
• Psychosocial factors
• Mechanical contact stress

Additional factors can play a role in how an individual will respond to repeated physical exertions. These include:

• The individual’s physical strength and conditioning
• Nutrition
• Physical activities at home and at play
• Emotional and psychological issues
• Attitudes toward work

Prevention and management of RSI’s

Intervention has a positive effect in preventing and treating cumulative trauma disorders. One study demonstrated that for every dollar spent on intervention programs, six dollars were saved in terms of direct costs associated with workers’ compensation claims. RSI’s can be prevented through intervention directed to both the individual and the job.

Individual interventions may include education on:

• Exercise including cardiovascular, strengthening and stretching
• Work pacing
• Working postures and positioning
• Nutrition
• Stress management

Job interventions may include:

• Ergonomics evaluations to improve workplace design
• Evaluation of psychosocial and cognitive job factors

Clinical management of RSI’s

If the RSI already exists and all attempts to self manage the condition fail to relieve the pain or stiffness, it is time to get help in managing the problem. Assuming that all of the self-management and job management approaches are being addressed, the clinical management of RSI’s may involve any of the following and usually in this order:

• Restore the muscles to their normal state:This may involve Active Release Technique® and massage therapy to eliminate any scar tissue, physical modalities such as ultrasound or electrical modalities, mobilization and assisted stretching techniques, joint manipulation, nutrition, or acupuncture.
• Eliminate any compensation patterns: Your body will adapt to the way you use it. If chronic postures have been adopted for a period of time, or if pain has been present for a prolonged period, the body has created compensation patterns to the conditions. When the pain or posture has been corrected, your body may still be using these compensation patterns. They may include asymmetrical movement patterns such as limping, or postural habits such as slouching. Before any stabilization or strengthening can begin, these patterns must be eliminated or they will be perpetuated and lead to future problems.
• Stabilize the affected areas: The fine-tuning of motion in most joints of the body is controlled by smaller “stabilizing” muscles. If these muscles are injured or dysfunctional, then the joint will not move properly when the larger “force generating” muscles contract. If this occurs, then the joint and other tissues (tendons and ligaments) are stressed. This can lead to chronic dysfunction and repeated injury. Once the tissues have been returned to a normal state, then these small stabilizing muscles must be retrained to function properly. Exercises that train these muscles include stability exercises such as those performed on an exercise ball, wobble board, or any other device that challenges balance. The joint stabilizing muscles must be retrained before any strength exercises are performed to ensure that the joints are stable and will not be re-injured.
• Strengthen the affected areas: The final stage of rehabilitation is strengthening the larger “force generating” muscles through resistance training programs. These programs may take advantage of weights, elastic tubing, lifting body weight, or any other program that will fit into the individuals goals, lifestyle and resources.