Topical pain relief products are used for a wide range of muscle and joint conditions, but to understand how and why they are used it is helpful to know a little about what happens below the skin to cause these problems.

Most customers who purchase topical pain relief products in pharmacies are after something to help with a problem that is affecting one or more of their joints. A joint is the point in the body at which two bones connect. However, at most sites in the body, the two bones are not directly joined because while this would provide the structural support that is a fundamental function of the skeleton, it would not allow for any movement. This is facilitated by the inclusion of cartilage, a smooth connective tissue that covers the ends of the bones. Some joints – those that allow the widest range of movement, such as the knees and wrists – also contain synovial fluid, which provides extra lubrication and acts as a shock absorber.

Bones move as a result of muscles contracting. Skeletal muscles can only pull in one direction, so always exist in pairs. For example, contracting the bicep muscle in the upper arm allows the lower arm to move towards the body, and contracting the opposing tricep muscle allows the lower arm to move away again.

Tendons – tough bands of connective tissue – attach muscles to bones, while ligaments, which are similar in structure, hold bones together, in some cases restricting movement in order to protect a joint.