1 – drop jump into hand clean (set up bar in a hang clean position, so at about mid thigh height. Place a box in front of it. Drop off box and on way up go straight into a hang clean/ jump shrug etc…
I’ve seen this one done before. Not sure what would be the benefit over doing a squat jump coming off a box. In fact, I think that option would probably produce much higher power outputs.
2 – Partner assisted squat jumps (have a partner standing behind you with his hands around your waste. As you are exploding up in the jump squat, your partner push you up as quick as he can. You actually end up, jumping very fast and high in the air. Land on a mat
I don’t actually think this would cause faster contraction times. It would just cause faster limb speeds. In fact, I’m not aware of any evidence to suggest that aiding external forces (such as overspeed towing devices) actually cause faster contractions. In fact, the overspeed towing actually increases ground contact time slightly which is the opposite of what you’d want to happen. As Mort said it could be some “dumb shit that actually works” but I don’t think it’s due to contractile speeds.
3 – Step up shot throws (start with one leg on box in step up position. Hold a light or heavy shot/med ball. Explode upwards and forwardoff the box while chest throwing the shot. Land running forward.
I’ve done this one before. It sounds very good but it’s kinda awkward…which makes it hard to REALLY get after it.
4 – Jump lunge w/weight swing (hold a kettle bell/ dumbell in both hands, between leg. Get in lunge position and jump forward, switching legs each time, while swinging the bumbell for extra momentum.
This one could be interesting but it sounds like it could be a little awkward / dangerous. Have you tried it?