If grasshoppers were the size of people they could leap the length of a basketball court,
and a flea can jump 100 times its' body length - that's like you jumping to the top of a 34 storey building!!
Human muscles are sadly not as powerful as this!
We have 3 types of muscle tissue - skeletal muscle which we can voluntarily control, cardiac muscle which controls the heart and is involuntary, and smooth muscle which is in the walls of hollow structures e.g. blood vessels and stomach etc. The latter is usually controlled involuntarily but can be affected by hormones and neurotransmitters hence the upset stomach when one is nervous.
Did you know that increases in strength due to short term training (e.g. 8-20 weeks) are due to neural adaptations (nerve changes) rather than increasing muscle size. Improvements also only occur with the specific exercises practiced, for instance, if you use the leg press at the gym to build up you Quadriceps (thigh muscles), this will not necessarily mean that you can run any faster or jump any higher!
Physiotherapy and muscle strengthening
Cathedral Physiotherapy uses the above principles to ascertain how best to rehabilitate you depending on what it is you need to achieve. If for instance you are getting hip pain after 20 mins of running, it may be that you need to strengthen your gluteus medius muscle, a muscle which helps control your hip rotation and fatigues easily. An exercise program given to you would reflect the needs of this muscle in terms of levels of resistance and repetitions given. Exercises would progress to being as functional as possible to ensure carry-over of the exercise regimes, therefore maximising your functional improvement.