The Glute Ham Raise Developer (GHD) is regarded as one of the best workout tools for the posterior chain (lower back, glutes, hamstrings and calves).
The glute-ham raise enables an athlete to work the entire length of the spine and both the knee- and hip-extension functions of the hamstrings. This is not possible with the back-extension benches found in most gyms. The design of the glute-ham developer allows an athlete to strengthen the erectors especially in the middle portion, which, in mos sports, is exposed to high forces. Another plus for the glute-ham raise is that it is one of the most important exercises for preventing back and knee injuries, especially to the anterior cruciate ligament (ACL).