Check out this informative clip with Physio Simon and Andrew on stretching for the quads and hamstrings.
Whether you are physically active or relatively sedentary, you are vulnerable to overly tight quadriceps that create imbalanced muscle tension at the hips. If left unaddressed, too-tight quadriceps can effect posture and body mechanics, leading to back pain and making you predisposed to injuries of the hip and knees.
Tight hamstrings can cause the hips and pelvis to rotate back flattening the lower back and causing back problems. Tight hamstrings can also be responsible for postural problems and other back problems such as sacroiliac joint pain, as they will tend to pull the pelvis out of normal position.
If your muscles have tightened up then blood has been squeezed out of them therefore your muscles are working at less than 100 % of capacity and your performance will be down as a result. Regular Physiotherapy for hamstring muscles and hamstring stretching to improve muscle condition will not only reduce the likelihood of injury but may also improve sporting performance.