The Elbow & Repetitive Strain Injuries

Unlike the shoulder, the elbow joint has a tremendous amount of bony stability. The lower end of the long bone of the upper arm (the humerus) meets the two long forearm bones (the radius and the ulna) at the elbow. The majority of the muscles that bend the wrist and the fingers attach to the inner portion of the elbow. The majority of the muscles that straighten the wrist and the fingers attach to the outer portion of the elbow.

The neutral position of the elbow, with the arm relaxed at the side of the body, is with the thumb facing forward and the palm facing toward the body. With the elbow bent, this neutral position is the “handshake” position.
Factors that Contribute to Elbow Pain

  • Repetitive wrist movement, especially with the forearm fully rotated palm-up or palm-down, repetitive rotation of the forearm, and repetitive elbow bending and straightening can all contribute to inflammation of the tendons as they insert into the elbow.
  • Bony and ligamentous grooves and tunnels near the elbow through which the three main nerves that provide power and sensation to the hand pass. The shearing motion or compression of the tendon and nerves as they pass through these tight areas can contribute to repetitive strain injuries.
  • The degree of the elbow carrying angle (the angle of deviation of the forearm bones in relationship to the upper arm bone when the arm is held at the side with the palm facing forward).
  • Maneuvering the arms around a larger upper body when placing the hands on the keyboard is also a factor.

Cubital Tunnel Syndrome

When you hit your “funny bone” you are actually hitting the ulnar nerve as it passes through a bony groove at the inside of the elbow. The nerve is particularly vulnerable as it passes through this superficial groove. Bending the elbow stretches the nerve through this groove tautly. Holding the elbow bent for prolonged periods, such as when holding a phone to the ear or sleeping with the elbows bent, can cause this nerve to become irritated. If you experience aching along the small finger (ulnar) aspect of the forearm and hand, or if you have tingling or numbness in the ring and small finger, it is especially important to avoid positioning the elbow in a bent position, either with activity or at night. Avoid repetitive elbow bending and straightening. Contact a medical professional for treatment.
Tennis Elbow (Lateral Epicondylitis)

Tennis elbow initially begins as an inflammation where the muscles attach to the outside edge of the elbow. Activities that contribute to this inflammation include repetitively pulling back (extending) the wrist and the fingers; repetitively rotating the forearm palm-up and palm-down, especially when holding an object in the hand; and lifting objects with the forearm rotated in the palm-down (pronated) position. Carrying a suitcase, briefcase or laptop backpack are activities that can cause tennis elbow.
Golfer’s Elbow (Medial Epicondylitis)

Golfer’s elbow is similar to tennis elbow, except that it begins as an inflammation where the muscles attach to the inside edge of the elbow. Activities that contribute to this inflammation include repetitively bending the wrist and closing the fingers; performing fine motor activities with the wrist bent, and repetitively rotating the forearm.

The farther away from the body that you perform activity, the more tension that is placed on the tendons where they insert into the elbow.

RSI and Prevention

Positioning

      • Avoid sleeping with the elbow bent more than 90 degrees to reduce the amount of stress on the nerve.
      • Don’t sleep with the hands placed behind the head.
      • Avoid sleeping on your stomach.
      • Use soft pillows under the arms.
      • Wear a sleeve with a pad that protects the elbow or wrap an ace bandage around a small, soft pad.

Computer Use

    • Position the keyboard so that the elbows are open more than 90 degrees.
    • Pad any sharply angled surfaces that the arms rest upon. Or place a folded towel under the arms as a cushion.
    • Don’t lean on the elbows.
    • Avoid repetitive elbow bending and straightening, excessive wrist movement or repetitive forearm rotation.
    • Use a split keyboard, especially if you find that you need to deviate the wrists out of the
      neutral position (middle finger in line with the forearm bones) when placing the fingers on the keyboard. This is particularly important if you have a large elbow carrying angle or a larger upper body.
    • Move the mouse from the shoulder, not the wrist.
    • Take frequent micro-breaks.
    • Stretch often.
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Trigger Finger – Repetitive Strain Finger Pain

Mouse and keyboard use can cause finger pain. One common cause of finger pain is called trigger finger. Trigger finger is a swelling of the tendon or tendon sheath in the palm of the hand of the tendons that bend the fingers. This swelling prevents the tendon from gliding smoothly through the sheath and the “pulley” (ligament) which holds the tendon to the bone. Trigger finger occurs most frequently in the middle finger and the ring finger, but it can occur in any finger or the thumb.SYMPTOMS

  • A locking, snapping, popping or catching sensation in the finger while making a fist.
  • This “triggering” of the finger can be quite painful at times.
  • The finger may “lock” into a bent position.
  • There will most likely be pain or tenderness in the palm of the hand over the site of the pulley which holds the tendon close to the bone.
  • There may be joint stiffness and pain in the affected finger.

OCCUPATIONAL CAUSES

  • Repetitively gripping or bending and straightening the fingers (e.g. – mouse clicking)
  • Sustained gripping (e.g. – squeezing the mouse forcefully or holding a pen in a “death grip”)
  • Using tools that have handles with sharp or hard edges

ERGONOMICS

  • Avoid repetitive grasping and releasing of objects. Modify the activity if you are unable to avoid it. Look for ergonomic mice or larger barreled pens. Change your typing style so that your fingers are relaxed on the keyboard and mouse.
  • Avoid sustained grasp.
  • Keep the fingers relaxed over the keyboard. Do not plant your wrist down on the wrist rest while typing as this causes excessive and stressful finger movements to reach all the keys. Rather, the wrist should glide over the wrist rest, allowing the fingers to be positioned over the keys in a relaxed manner.
  • Purchase tools with padded, comfortable handles.
  • Handles should have some texture for easier holding. Slippery surfaces require more forceful grasping.
  • Minimize repetition. Periodically rest the hands during repetitive or stressful activity. Stretch frequently during repetitive activity.
  • Slow down!
  • Use the lightest grip possible (on tools, pens, the mouse, the steering wheel, etc.) that still allows you to maintain good control.
  • Use the least amount of force necessary during the activity.
  • Use the appropriate tool for the job.
  • Use ergonomically designed tools if available (modified or padded handles, larger grips with good traction, handles with modified designs).
  • Make sure that tools are in good condition and that cutting edges are sharp (reduces the force needed to use the tool).
  • Alternate work activities so the hands are not performing any one task repetitively for any length of time.