If you've spent enough time at a gym, you've probably seen a weightlifter use the item pictured above. Its a wrist strap which some people use to aid in doing pullups because their grip isn't strong enough. You might have also seen people use a weightlifting belt that providers lower back support or stacking tons of weight on a machine that only moves in one dimension. All are good examples of what not to do.
If a certain body part is the weak link in your kinetic chain then you shouldn't bypass it. Instead you should dedicate time to strengthening it. Using any of the devices mentioned above is not very functional and might lead to injury.
When you bypass a bodypart in your workouts you create an imbalance of a weak joint or muscle next to a strong one, an imbalance that might come back to haunt you the next time you are playing a sport or even just moving a heavy object.
One of the core tenets of our philosophy is to identify the weak points in our patients and clients and develop focused routines to strengthen them and eliminate any imbalances. You would be well served in doing the same thing yourself. In the long run you'll find that you will be much stronger as a result.