How the bones, muscles, and joints affect running is called biomechanics. Faulty biomechanics can affect running performance and risk for injury. Examples are a curved spine, differences in leg length, high arches, and excessive muscle tightness. A sign of this is abnormal shoe wear patterns. The right shoes can correct a biomechanical problem.
Proper shoes can also reduce the risk for overuse injuries of the knees and ankles.
Terrain, altitude, temperature, and air quality can impact performance and physical health. Run on soft surfaces like a track, dirt road, grass, or treadmill. Avoid running hills. Downhill running puts extra stress on the knee and lower leg. Avoid running in hot or cold temperature extremes and when pollution levels are high.