execution: control the descent of the weight as your knees track toward your shoulders. dont let them buckle inward or outward. try to reach a 90-degree bend in your knees, but stop short of allowing your lower back and glutes to curl up off the pad. smoothly reverse direction, pressing through your heels back to the top, but dont lock your out your knees.
tip: keep the movement consistent all the way through. control the negative motion, dont let the platform just drop. and, use a strong motion on the positive, being careful not to use too much of an explosive a speed.
LYING LEG CURLS
start: secure your hips flat on the platform, gripping the sides for stability, with your knees just off the edge of the pad. avoid pulling hard through your hands so you dont gain leverage on the movement that might detract from the work being done by the hamstrings.
execution: in a strong but controlled motion, contract your hamstrings to curl the lever toward your butt, bringing it up as high as you can without lifting your butt from the platform. squeeze at the point of peaking contraction before slowly lowering to the start, but dont allow the weight stack to touch down between reps.
tip: this is the only exercise where you may do down to 12 reps on the last couple of sets, bu thats very rare. almost always, its in the 20 to 50 range.
start: sit squarely in the apparatus with your feet hip width apart and pointed straight ahead. the edge of the seat should be secured against the back of your knee joints. brace yourself by grabbing the sides of the seat.
execution: contracting your quads, straighten your legs to full extension, holding the peak contracted position at the top for a count and slowly lowering to take advantage of the negative resistance on the descent.
tip: dont lean your body backward as you lift. thats using body leverage and it removes stress from your quad muscles. for this move, high reps are great.
SEATED CALF RAISES
start: the bent knee position puts the gastrocnemius on stretch so only the soleus is targeted here. place the balls of your feet on the footplate, with the thigh pad just behind your knees, so all stress is directly on top of your lower leg.
execution: flex your calves through a full range of motion using slow burn reps, holding the peak contraction for a count of 1 to 2 seconds at the top. release to fully stretch the calf and reverse direction without bouncing.
tip: be careful of using burn rep bounces at the end o fa set because they can tear your achilles tendon. use smooth, full range of motion for 20 to 30 reps.
Source: Muscle Mag ~ September 2009 ~ Big Will's leg workout.