The Iliotibial band isn’t a muscle however a fibrinous band. It is on the surface of the thigh from the top of the iliac crest (hip bone), down the side of the thigh and attaches to the outside of the tibia (shin), just under the knee. The Iliotibial band helps keeps the knee stable and aids in flexion of the knee joint, It’s the quadriceps muscles assistant.
The Tenosr Fasciae Latae (TFL) muscle is located on the top of the outer thigh and the Iliotibial band attaches to it at the top of the hip bone, to form a continuous strip that runs along the side of the leg. The tensor fasciae latae movement actions are to abduct the thigh or allow the thigh and leg to move in a lateral motion. Standing with your feet together and raising your leg out to the side in the frontal plane, this is the action of the TFL. The tensor fasciae latae also aids the hip flexors (iliopsoas) in flexion of the hip or thigh.
Foam Roller Exercises for Your Iliotibial Band (IT Band) and Tensor Fasciae Latae (TFL) Muscles

• Sit on the foam roller and roll to put your weight on the left side of your leg, at the top of your hip.
• Extend your left leg out straight, in the same position with your hip and knee.
• Position your right leg, bent in and put over the front of your left straight leg on the floor.
• Push off with your right foot as you roll down your entire leg from the hip to the knee, keeping your arms straight and non-moving in front of you.
• Do not roll over any joints like your hip or knee.
• To increase the intensity and the iliotibial band myofacial release, drop harder into the foam roller adding more pressure.
• Rotate your leg  slightly, to one side or the other to get the exact hot spot that needs attention.