The Anatomy of the Repetitive Strain Injuries (RSI) Epidemic

The Anatomy of the RSI Epidemicherniation in the early phase of disease. This explains
Repetitive Strain Injury (RSI) is fast becoming one ofreduced diagnostics of disk herniation during MRI in the
the most common forms of disability in the workplace.supine position as compared to the Standing MRI.
In some industries it is already the number one causeEventually, frank herniation is seen on supine MRI.
of a temporary and permanent disability. In this article IWith increasing neck compression the nerve
will explain why and how we develop the elusive RSI.conduction in the neck supplying the arm becomes
The definition of RSI:more and more affected. Initially the nerve is
Repetitive strain injury is a medical term used totemporarily and only partially interrupted. Over time, as
describe a pain or discomfort of the upper limb.the spinal compression and rotation deepens, the
Although a 'repetitive strain' can occur in any area ofnerve interruption becomes more constant and severe.
the body, physicians typically apply the term to a painMuscles down the affected arm will shorten following
of the arm unit including the neck, shoulder upper back,a supply pattern according to nerve roots affected
arm, forearm and hand, that is related to repetitive(Cannon's Law). As well, repeated local muscle injury
tasks. RSI is really an umbrella term used to catch anyfrom continued repetitive work will contribute to further
and all pains of the arm, but the most common formslimb muscle shortening.
include tennis and golfer's elbow, carpal tunnelCertain Muscle groups will contribute to different
syndrome, ulnar neuritis, metacarpalgia, rotator cuff ofsymptoms of numbness, tingling, pain and weakness of
the shoulder, chronic neck and upper back pain andthe arm. In carpal tunnel, the pectoral (chest muscle)
limb numbness.shortening will cause a traction injury to the median
The signs and symptoms of RSI:nerve at the front of the shoulder. This in turn, causes
The signs and symptoms of RSI vary depending ona pulling effect on the nerve which translates to the
the exact areas of the arm and neck involved in thenerve being lifted and then caught at the undersurface
pain syndrome; however, the most common RSIof the carpal tunnel. Entrapment and swelling of the
complaints include the following:nerve will then cause numbness, tingling and pain of the
Numbness and tingling of the arm and / or handthumb, index, middle and half of the ring finger
Pain and / or weakness of the upper arm and / orrecreating the ever popular pattern of carpal tunnel
forearm, and / or wrist, and / or handsyndrome.
Reduced range of motion and / or stiffness of theIn ulnar neuritis, the lattissimus dorsi and the
shoulder, elbow, wrist or fingerssubscapularis muscles will shorten from reduced nerve
Difficulty lifting of objects and / or tendency to dropsupply of C6 to T1. This shortening will then cause a
objects (dropsy)similar traction phenomenon of the ulnar nerve at the
The tendency of pain and / or numbness to increaseback of the shoulder. This traction will then cause the
with repetitive activity and at restulnar nerve to catch at the elbow causing golfers-like
Background of RSI:elbow pain and pain over the nerve when leaning on
RSI is considered a soft tissue pain syndromethe elbow. As this progresses, the ulnar nerve actually
whereby the pain is derived from a disorder of therolls over the inner elbow or medial epicondyle and can
muscles and tendons of the neck and limb. To fullybe felt by examination by palpating the medial
understand how muscles can cause disease, it isepicondyle and while flexing the elbow. This indicates
important to understand the current principles ofvery significant traction of the ulnar nerve coming from
myofascial pain (MFP) and myofascial dysfunctionthe back of the shoulder - otherwise known as
(MFD).posterior thoracic outlet syndrome. The classical
Muscles shorten and can potentially scar in asymptoms will be of numbness and tingling of the little
shortened position as a result of injury or exercise. Thisfingers and eventually pain in the fingers and ulnar side
process of shortening is often exaggerated at rest.of the hand.
Therefore, muscles that work repeatedly in a particularIn tennis elbow, the outer elbow (extensors) can
action eventually shorten and over time, will developshorten and scar as a result of compression of C4 to
some form of scar formation in areas of the muscle.C6 in the neck (due to contractures within deep
These scars can be described as microinfarcts, orintrinsic muscles of the neck at these levels) . The
more popularly, as trigger points. In traumatic cases,forearm shortening will cause persistent tension of the
muscles will shorten and scar in a much moreextensor tendon which causes inflammation of the
accelerated period of time and often more severely.tendon. The persistent shortening of the extensor
Muscles shorten persistently if nerve conduction to thatgroup will apply traction to the lateral epicondyle of the
muscle is interrupted. This is known as Cannon's Law,affected arm causing pain, swelling and bony changes
and is very important in understanding how we canover the elbow. This mechanism helps to explain the
develop repetitive strain injury. Walter Cannon wasdifficult nature in treating tennis elbow, as well as the
able to clearly demonstrate that muscles becomehigh failure rate with local elbow therapy.
super-sensitive and ultimately persistently shortenedGolfer's elbow has a similar mechanism to tennis
with eventual scarring when their nerve conduction iselbow, only the spinal segments involved are typically
partially interrupted. For example, if the nerve supply toC6 to T1. Often golfer elbow is associated with ulnar
the forearm extensors is interrupted by a diskneuritis as the same spinal segments are involved.
compressing the C4 or C5 nerve root, the forearmOther conditions can be recreated by similar spinal and
extensors will persistently shorten and cause chroniclimb muscle patterns.
tennis elbow.Computer-related RSI often proves to be more
Shortened muscles around a joint will often change theominous than assembly work. The problem is that
static position of normal movement of the joint.keyboarding is a static injury. It is evident that static
Furthermore, persistent compression of the joint mayrepetitive work is possibly the worst case scenario, as
occur and contribute to an abnormal and acceleratedstatic muscles not only shorten after injury, but also at
wear pattern of cartilage and eventually the joint. Jointthe time of injury. In this case the weakness of the
pain, stiffness and decreased range of motion aremuscles can be more exaggerated as the static
common side effects. Over time, destruction of therepetitive action does not allow for increase in muscle
joint and osteoarthritis are predictable complications.strength as compared with standard active repetitive
The spine is also affected by these principles ofwork.
persistent compression when the deep intrinsic spinalFurthermore, the computer-related RSI often affects
muscles are injured and develop shortening andthe upper back area (thoracic spine); an area which
contractures. The vertebral compression will causehas secondary nerve supply to the arm. The thoracic
disk herniation and spinal stenosis. The vertebrae, disks,spine can be extraordinary to treat particularly in the
nerve roots and the spinal cord can be affected bypresence of kyphosis. The end result of
herniated disks and swollen facet joints.computer-related RSI is a person with a hump back,
To explain, these deep spinal muscles change theforward neck, forward shoulders, compressed disks,
spinal positioning, cause mal-rotation of the vertebraesuffering diffuse muscle shortening and multiple
and non-movement of the spinal segments. This willentrapped nerves, and typically affecting both arms.
lead to premature or accelerated disk wear, diskThe Treatment of RSI:
herniation, arthritis of the facet joints, and increase the*The treatment of a complicated/chronic RSI begins
risk of compression fractures of the vertebrae. This iswith a detailed history and examination often indicating
true at all locations of the spine, but is more prevalentfar more disease than initially thought.
at the levels of C1 to C2, C4 to C6, T11 to L1 and L4 to*Detailed patient education of the mechanism and
S1. In the case of RSI, we are typically seeingexercise physiology is important such that they ca be
compression of the segments of C4 to C7.aware of aggravating factors and to succeed with
Application of these principles:personal exercises.
Let's look at the typical assembly worker. He or she*Physicians and nurses need be more aware of the
will often perform the same group of tasks and usevarious patterns of RSI for their early recognition and
the same muscle groups of the neck and arm asproper treatment.
much as six hundred times per day. The basic effect*The key part of actual therapy must include the
is to overwork / exercise the muscles of the neck andimplementation of spine and limb "neuropathic"
arm. The first changes that occur are of typicalstretching and resistance training (the Lamb Program)
shortening of the deep spinal muscles of the base ofthat allows for all muscle groups affected to be
the neck (multifidus and deep rotators) and of thetreated, and for spinal and limb segments to be
shoulder outlet and forearm muscles. Specifically I seeproperly repositioned.
shortening and scarring at the levels of C4 to C7 and*It is important to recognize the limitations of imaging
of the back of the shoulder (latissimus dorsi andtechnology, i.e. MRI fails to detect an estimated 40% of
subscapularis) and of the front of the shoulderdisk disease.
(pectoral minor and major), shortening and scarring of*The Implementation of injury avoidance and education
the forearm and hand muscles (forearm flexors,of RSI-injury factors for the patient helps to reduce
extensors and hand metacarpals) are all generallyre-injury and progression of disease.
affected to some degree.*The use of specialized injection technologies-surgical
Early on, the exam will show mild trigger point ordry needling, the Patented Lamb Method of Spinal
tenderness along the muscle groups mentioned above.Botox, injectable NSAIDS can drastically reverse the
Some weakness is often present as the muscles arecompressive effect within the spinal anatomy and help
working below their maximum of their efficiency as amost RSI's and other pain syndromes.
result of being shortened. The individual will often have*Specialized relaxation training systems help to reduce
only slightly reduced range of motion of the neck andRSI-related muscle tension (i.e. ASeRT Systems).
arm unit. However, over time the range of motion*Positional education for sitting, standing and sleeping,
becomes obviously reduced and the pain symptomsas well as proper sleep education help to reduce the
increase as the condition progresses. X-ray and CATprogressive pattern of bad sleep and bad pain.
scan imaging will show loss of normal curvature of the*The implementation of laser/magnetic combination
neck, and examination will show forward rolling of thetherapy and MET has demonstrated effectiveness as
shoulders, winging of the scapula, decreased pulse withan adjunct to various pain syndromes including RSI.
elevation of the limb, and even acute joint swelling of*MET or micro-current therapy is the latest in
the affected joints.electronic or electro-medicine that properly addresses
The loss of normal curvature in the neck indicatesthe abnormal electrical potential concerns in chronic
prolonged and persistent shortening of the deep spinalpain and RSI versus TENS or EMS which are
muscles of the neck; a so-called tenting effect. As thedemonstrating oxidizing potential of soft tissue with
muscles tighten, they ratchet the neck straight like arepeated use.
tent pole under tension. The effect on the spine is to*Obviously the addition of medications can be a major
create a persistent compression on one or more diskadjunct to RSI and other chronic pains, and I will quickly
and vertebrae. As well, the natural or normal positioningcomment on two medications.
of the vertebrae and disks is altered. The range of*Anti-inflammatories have a beneficial effect in RSI, but
motion of the spinal segments becomes obviouslymust be tapered when stopping, otherwise reactive
reduced as several vertebrae actually fail to move.inflammation and spasm can occur. Lyrica, a new
Disks come under pressure and start to wear at their"anti-neuropathic" agent has been helpful in chronic pain.
sidewalls, much like a deflated car tire supporting anI have found improvement in deep spinal muscle
over-weighted car. The affected vertebrae will have apathology in many patients indicating that cessation of
slight rotation to the affected side caused by the pulltransmission of pain information has a relaxing effect
of the intrinsic muscles. Disk bulging and herniation canupon spinal and skeletal muscles.
occur and can also oscillate between bulge and