whereas patient B could only achieve 83 Nm. It has been shown in this section that the therapist must play a far greater role during rehabilitation than is the case when using other isokinetic equipment. This probably has additional merits of its own but is a vital ingredient to ensure the success of the exerciser. Indeed, it is a small price to pay when one considers that this exerciser will retail at a fraction o f the cost of imported equipment. The dire need for affordable equipment in this country cannot be over-stressed. CONCLUDING REMARKS An inexpensive exerciser has been described here which closely approximates the performance o f state-of-the-art isokinetic exerci­ sers. Unlike other exercisers o f this type, lower limb velocity cannot be set at the outset but the therapist can ensure a particular velocity range on the basis o f patient strength. It is also evident from the foregoing sections that the two most expensive items on the exerciser are commercially obtainable shock absorbers. It is thus obvious that this exerciser will be dramatically cheaper than any o f the isokinetic exercisers currently on the market. In fulfillment o f the BER U requirements it is evident that, pro­ vided the geometry o f the mechanism and the damping coefficient o f the shock absorber are known, the system is fully calibratable and is capable o f providing reproducible results over the entire range of movement. It has also been shown in the above sections that simple electronics and computer interfacing allow the simultaneous m eas­ urement of torque and angle in real time. One definite advantage of this exerciser over those like the Orthotron is that it allows enforce­ ment o f limited arc rotation which is important in many rehabilitation programs. ACKNOWLEDGEMENTS The author gratefully acknowledges Dr D F da Silva for his assist­ ance during the preliminary design phases and Drs EH Rosenberg and CM Lipman for providing financial support. Messrs T Rossini and TA Stacey are also acknowledged for setting up the data acquisi­ tion equipment and performing the experiments. REFERENCES 1. Thistle HG, Hislop HJ, Moffroid M eied. Isokinetic contraction: a new concept of resistive exercise. Archives o f Physical Medicine and Rehabilitation 1967;48:279-282. 2. Hislop HJ and Perrine JJ. The isokinetic concept of exercise. Physical Therapy 1967;47:114-117. 3. da Silva DF and Greenblatt D. The design of an isokinetic leg exerciser. 1986: Final year design report. University of the Witwatersrand. POST-CONGRESS SYMPOSIUM ON PAIN - A REPORT BACK b y ] C Beenhakker A symposium on pain which was held in Cambridge during Au­ gust, attracted speakers and participants world wide. Many thought- provoking and challenging papers were given by speakers who are specialists in their own field o f practice or research. Day one was devoted to the theories and mechanisms o f pain. When discussing the role o f nerves from muscles and joints, Profes­ sor P D Wall suggested that physiotherapy caused sensory stimula­ tion o f unmyelinated nerve fibres. This resulted in the release o f local chemicals together with stimulation o f the sympathetic system and o f motor nerves. Dr Newham, a physiologist, discussed the two types of muscle pain associated with exercise. The pain occurring during exercise is prob­ ably caused by trauma to muscles, severe metabolic depletion o f ATP and/or stretching of untrained muscles. Delayed onset of pain is mainly due to eccentric muscle contractions and occurs 12-20 hours after exercise. It is probably associated with muscle fatigue and impaired force generation. Contrary to what we believed, studies have shown that lactic acid is not responsible for ischemic pain. An interesting talk was given by Dr Williams, a neuro-surgeon, who outlined the chemical theory o f pain relief and compared the electro physiological to the biochemical approach. H e did not believe in surgery for most types o f pain relief and suggested that the best neuro-surgeon was one without arms! Several speakers discussed the function and value o f pain clinics which have proliferated all over the world. Mrs Allan from the Boston pain clinic discussed the role o f the physiotherapist in the inter disciplinary pain management team. As chronic pain leads to stress which causes further pain and dysfunction, Mrs Allan suggested that one o f the best ways o f dealing with this pain is by teaching stress coping management techniques. During day two presentations were made on trials carried out using electrotherapy modalities to relieve pain. Dr Mary Dyson discussed the w orking o f low level laser therapy and its e ffe c ts, which are mainly molecular vibration with som e electrical excitation. U se o f pulsed electromagnetic energy, interferential and pulsed short­ wave diathermy were also discussed. One afternoon was devoted to the theories of the psychological process in pain management. Mrs Klaber Moffett from the Nuffield Research Unit discussed how pain may be indirectly measured by behavioural responses to pain. For example by noting the increase or decrease in drug intake, alteration in measurement o f joint range or changes in functional activity, an indication o f the patient's pain level can be established. U se is also made o f pain diaries which are kept by the patient as well as the various pain scales and questionnaires which are mainly subjective. Dr Pither described the coping mechanisms regarding pain and how function is affected. He described a survey o f 89 patients who had chronic pain wherein it was found that these patients were over investigated and over treated, and very little advice and information had been given to the patients. He felt that many patients had iatrogenic distress and dysfunction and queried whether doctors were half the problem in chronic pain. The Input Programme which advocates a shift from curing pain to encouraging coping with existing pain was described by Ms Ridout. This program which is held in a group setting runs over five days a week for four weeks. Components o f the programme include fitness training, goal setting, withdrawal from drugs, functional and social activities, relaxation and cognitive skills. Patients are encouraged to make plans, challenge unhelpful beliefs and feelings, set goals and reinforce positive behaviour. During the final day papers were presented on the various m o­ dalities which may be used in the treatment o f pain. Dr Baldry defined myofascial pain and trigger points and discussed the use o f acupuncture. Mr Deadham, Editor o f the Journal o f Chinese m e­ dicine outlined the holistic approach o f eastern medicine while Ms Frampton described the use o f TNS. She discussed the differences between cortical pain such as causalgia and phantom pain and pe­ ripheral pain. She found that the most successful use o f TNS was using a width o f 50-360ms, 10-100 pulses per second at 0-50ma, which is given for eight hours a day over two to three weeks. An interesting discussion on manual therapy was given by Miss Thompson who postulated that pain was caused by lack of movement in joints, oedema, muscle spasm, joint entrapment or scar tissue. All o f these could be managed by massage, mobilisation, passive stretch­ ing, connective tissue massage, manipulation, hydrotherapy, acu­ puncture and PNF. Manual therapy is its broadest sense has been found to be a very useful tool if the correct technique is used at the right site. It is also important to be aware of the coping style o f the patient. The general impression gained from the symposium was that although it was important to relieve the physical aspect of chronic pain, this alone would not ensure a cure or even reduction in pain unless the cognitive and psychological aspects are considered concur­ rently. Bladsy 22 Fisioterapie, M ei 1992, dee! 48 no 2 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. )