Accurate scientific assessment in the prevention and treatment of injury in the elite athlete is long overdue. The Elite Sports Assessment Centre is a purpose built 5000 sq ft, state-of-the-art sports medical and human perfor- mance measurement facility located on site at the Robert Jones and Agnes Hunt Orthopaedic and District Hospital NHS Trust in Oswestry, Wales.
It is equipped
with leading-edge technology and data gathering equipment designed to produce musculoskeletal assess- ments primarily for the profession- al football industry.
The ESA lab uses a dynamic testing process that replicates as closely as possi- ble the strains and activity on the knee joint caused by a football match. The results from a variety of tests are then used to build a picture of the workings and weaknesses of the joint and in partic- ular the anterior cruciate ligament.
information can then be used to help rehabilitate an athlete or take preventa- tive moves to reduce the likelihood of injury. Forewarned is forearmed.
Rupture of the anterior cruciate ligament (ACL) gives a useful example of the philos- ophy of the Elite Sports Assessment (ESA) unit at Oswestry. The conceptual model of joint stability includes the following fea- tures:-
PASSIVE - ligamentous laxity
ACTIVE - muscle strength - muscle activation patterns (1,2)
- rate of force development in muscle
- fatigue characteristics (3)
These features may be illustrated in the rehabilitation of the reconstructed ACL. A base line for the tests should be estab- lished as early as possible. If the athlete has not been tested previously as part of a possible prevention programme, it is important to test the uninjured leg as early as possible after injury although we realise there may be inter-leg discrepancy. Post- operative testing of the reconstructed ACL is then performed at 6, 12 and 24 weeks.
Post-operative testing 1. Laxity Autogeous grafts such as the patella ten- don graft lose then regain blood supply allowing changes in graft plasticity. One of the important aspects of rehabilitation is to “ligamentise” the graft.
How this is
best achieved is the subject of many ongo- ing scientific programmes.
Dynamic assessment of knee joint ligament perfor- mance using 3-D motion analysis
which we have found is maximal from 6-12 weeks, is measured using a specific arthrometer (4) or by commercially avail- able machines.
2. Muscle strength Such testing can give an indication of the potential psychological ceiling and ulti- mate strength capacity of the muscle group.
Strength testing undertaken using
isokinetic dynamometry does not always reflect the athletes’s performance capacity on the field of play.
3. Electromechanical delay (EMD) This is the time to get any external force response from the muscle group following neural stimulation.
Everyone involved with the injured athlete has a number of questions about the injury: ● What is the extent of the injury? ● Is there an underlying problem which may lead to recurrence? ● How can the rehabilitation be opti- mised? ● When can sport be resumed safely? And also: ● Could the injury have been prevented?
Assessment of knee joint ligament performance using an arthrometry system
It is typically in the
region of 30-40ms in a trained athlete but can double after injury, deconditioning or fatigue. Until now the test has been per- formed by volitional muscle action. Injury or deconditioning can have an inhibitory effect which may be overcome by using non-volitional testing with magnetic stim- ulation of the supplying nerve. Non-voli- tional testing better simulates the neuro- muscular response in a threatening situa- tion such as a football tackle when many of the responses are at a reflex level. Magnetic stimulation is also a fine indica- tor of fatigue characteristics.
4. Rate of force development This combines elements of explosive strength and electromechanical delay