Reduction of loading on the arthritic knee joint is one of the key interventions that is often under-utilised in primary care. Advice to wear good, well-fitting, supportive and impact-absorbing footwear is often given but this is often taken to mean hiking shoes or trainers – advice not always well received by the typical middle-aged or elderly woman with her sore knees.
However an interesting study from Brazil
that compared the loading on the knee on descending stairs in two different kinds of shoes may lead to more acceptable and hence more effective footwear advice. 1
It is now believed that wearing footwear that maintains foot mechanics as near as possible to barefoot walking leads to optimal (minimal) loading of the knee. The study used force plates and infrared cameras to analyse gait and in particular the 'knee adduction moment' (KAM) in 34 elderly women (half with symptomatic osteoarthritis of the knee) descending stairs in either bare feet, a conventional heeled shoe (maximum heel height 5 cm), or a flat, flexible, rubber-soled shoe. The latter was of an inexpensive and widely available type.
The results showed that the flat rubber-soled shoe produced lower loading of the knee, similar to barefoot walking, whereas loading was higher in the conventional heeled shoe. The study did not evaluate the experience of knee pain with the two different types of shoe, however, which is perhaps required before we all start recommending this type of footwear.