Hi ophqui, this is a common issue and we all come across it especially with large rugby type players. There are some you just can't handle but then there are ways to assist youself with some techniques. e.g. A lachmans for the ACL can be done with the patient in prone on the plinth and you can rest the leg on your thigh or a wedge to take it's weight as you perform a modified anterior draw type movement. I even use that when I am not sure of the end feel of the traditional method.

Think about trying to use simple props to support weight allowing you to just perform the movement with as little holding as possible. Also get used to supporting a limb with your hands and moving your body to facilitate the movement you require.

It's definitely a good idea to come up with your own tachniques to make this as easy as possible early in your career or else you will run into injury problems later on. Thus this is a sensible post and we thank you for your proactive approach.