Knee Strikes / Back leg:

Knee strikes utilise one of the body's natural weapons (the kneecap) transforming the leg into an incredibly powerful battering ram. Particularly effective when used against a soft tissue target, a knee strike is also a heck of an exercise. It uses both lower and lateral abdominals, glutes and front hip flexors and combines it all with the physics involved around the whiplash motion of the upper body, pivoting over the hip joint to help increase the power the move delivers. If you just spend an hour perfecting this move you will walk away with a perfectly good workout.   

What's involved: Front hip flexors, lower abs. lateral abs, lower back, quads (standing leg), glutes, calves (standing leg). 

Powered by: The explosiveness of the movement that raises the knee up towards a target and whips the upper body back. This means that a good core and strong hip flexors go a long way towards making this a really powerful move. 

Tip: Breathe out explosively as you bring your knee up. This helps tighten up your lower abdominals, flattening your stomach and aligning the lower ab muscles making the smooth transfer of torque from upper to lower body easier and increasing the power that can be delivered with each knee strike.