Or you can think it scientifically.
Newton's law states that for every action there is an equal opposite reaction. How does it apply to running jump.
First you want to gather momentum through the run up phase, trying to accelerate on approach, so make it a continual increase in speed. then transfer that momentum to vertical.
How? i Hear you say.
When you are top speed and is time to transition from run to jump, you take the last 2 steps hard into the ground as well as going down to a quarter squat, it is this spot you transfer all energy from running to the jumping. from here you should have come to a stop and using the moment from the speed you explode up.
some people come low, to help increase the speed they approach the jump, some step in front into the plant, this is how they feel they can transition the speed from the run to the jump.
Me i can't jump that high, but when i do run jump, i think to myself, get faster the more closer you get and power all that into the plant and from there jump up like you would do from a standing jump.
its all about experimenting and finding the method you feel can transition all the power from the run to the jump.
things that affect the transition from run to jump is that during acceleration, you slow down, and speed up also you slow down before going to the plan, which makes you use less power in the plant and therefore jump less high.
keys:
accelerate before plant (including walking to light running then jump is a acceleration)
step into the plant hard using the momentum from the run. think about forcing the power from the run into the ground of the plant step
standing jump from the plant.
things you could try in a grassy area for shock absorption, aim not to reach for something but to develop technique, if there is nothing there to reach you can focus solely on technique.
1.first try and run accelerating during the process until you reach fast speed.
2.same as above but at different speeds, slow, medium, fast, top speed, using the momentum from the running jump into the plan thinking to dig down deep imagine trying to create a deep imprint of your feet without raising your knees high for the jump, but instead go down to a squat to help force your feet into the ground.
3.next run at the different speeds of above, go into plant hard digging deep and from the plant do a standing jump.
for all the above methods, try to make it a smooth change, i.e. make sure when acclerating its a smooth increase without any little slow downs and increase after and don't slow down when going into the plan. practice it to help reduce the deceleration when going from running to plant and from plant don't waste a lot of time on the plant, i think that is called the ammortization, fancy phrase for duration from eccentric to concentric contraction, it should be continuous from the running, to the plant and from the plant to the standing jump.
hopefuly practicing the above should help develop muscle memory.
i hope this is helpful if not just neg it and hide it