Kneeling requirements and arthroplasty surgery.

We investigated the physical characteristics and symptoms related to kneeling in a normal population. One hundred people were recruited at random. Of these, 27 subjects had knee pain and 73 were normal. Measurements were in kilograms with subjects on scales in three positions: standing, kneeling at 90 degrees and kneeling at full flexion. All 73 normal subjects could kneel at 90 degrees with an average of 94% of their body weight and at full flexion with an average of 51% of their body weight. The 27 subjects with knee pain were able to kneel at 90 degrees with an average of 97% of their body weight and in full flexion with an average of 50% of their body weight. Weight transmitted through the knees at full flexion is significantly less than when at 90 degrees whether subjects had pain or not. Future development of knee arthroplasty, when catering for kneeling might need to concentrate on achieving a better range of movement.