A significant number of injuries that come through our door are a result of an accident in the workplace. It is an unfortunate statistic that finger, hand and upper limb injuries are very common in workplace injuries, if not the most common injuries.

• Injuries to the Upper Limb, Shoulder, Neck and Arms accounted for 39 perecent of all injuries.
• Traumatic joint, ligament, muscle and tendon injuries account for 43 percent of all injuries.  
• Specifically sprain/strain accounted for 28.7%, chronic joint or muscle conditions were 20.4%, Open Wounds & Cuts had 12.6% and Fractures were 8.5% of all injuries.

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Part of our hand therapy is to help people return to the workplace successfully. This requires:

1. Knowledge of the Injury
2. Tissue Healing Timeframes
3. Strength remodeling of the Tissues
4. Functional Capacity Evaluation with strength testing, lifting capacity, sensation and dexterity
5. Specific Workplace requirements of the Job
6. Patient Habits, Abilities, Psychosocial Aspects

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Before we can do a strength test or functional capacity evaluation, we must look at the healing and strength timeframes for the injured tissues. Below is a simplified timeframe to follow, however it depends on the nature of the injury as well – a crush, laceration, traction, compression, repetitive strain, a tear etc.:

1. Skin – takes 3-7 days to repair and remodel
2. Muscle – takes 3 weeks to repair and then starts remodeling.  Strength training should not occur before this is the muscle is torn.
3. Tendon – takes three – six weeks to repair before strengthening and remodeling.
4. Ligament – takes three weeks to repair and up to 8 weeks to be strong enough to strengthen and provide the required stability of the joint.
5. Bone – takes four weeks to get callus production for stability.  Six weeks for strength and full osteoclast activity.
6. Nerve – Wallerian degeneration takes 4 weeks before repair even starts.  Up to 18 months for remodeling.

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4 Components of Functional Capacity Evaluation

Strength Testing

General Grip Strength is tested with the Jaymar position at II. This is for comparative extrapolations to age and sex. Hand Dominance is important. A 10% difference between dominant and non-dominant hand is considered normal.

General Pinch Strength is tested with thumb and index finger.

Weight Bearing Strength is tested with a push down on a scale with the palm flat.  It can also be done in a fist position. Please note the position.

Rapid Exchange Grip Strength tests endurance or fatigue.  If they fatigue quickly (there is a significant drop in strength) then they are not ready to return to repetitive tasks requiring gripping.

Maximum Voluntary Testing is checking the effort of the patient. A bell curve on the graph indicates a maximum effort and results can be used.  If the strength is all over the place, then there may be other issues that need to be addressed with return to work as they have not done their best effort for whatever reason. You need to find out.

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Lifting Capacity

Unilateral lifting capacity is assessed using dumbbells/kettle bells of varying weights. Instructions are given to lift the given weight over the respective distance (Floor to Waist, Waist to Shoulder, Shoulder to Overhead). If you can, repeat five times without pain. The weight is then upgraded. We use 3kgs, 8kgs, 12kgs, 15kgs with a maximum of 20kgs.

Bilateral carrying capacity is assessed using a weight placed in a plastic crate (36cm x 36cm x 28cm) with handles located 3cm from the top of the crate. Instructions are given to carry the given weight over the respective distance (20m) without pain. To stop if pain is experienced. A successful attempt is recorded. The weight is upgraded if successful.

Patient evaluation of capacity and ability is important to record.

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Sensation

Monofilaments – test the sensation and give an indication of nerve recovery and what the patient can reliably feel. Very important for return to work with many jobs requiring adequate sensation before successful return can be expected. If not required for your patient a NA is appropriate with a comment of normal sensation.

Cold Tolerance – useful for jobs requiring people to work in cold or refrigerated environments. If not required for your patient a NA is appropriate.

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Dexterity – Manipulation

Sollerman’s three subtests are appropriate tests of dexterity and manipulation of objects. Again, certain jobs require more dexterity than others. It is a time scored tests out of 12.  If not required for your patient a NA is appropriate.  

This information is regularly asked for by doctors, rehabilitation co-ordinators and insurance companies. It is essential for physiotherapists to use reliable and reproduceable methods to support the predictions of weight and lifting restrictions. This is to ensure patients return to work as safely as possible to prevent re-injury and to protect ourselves in our profession. I believe further research needs to be done to simplify this process.