How do the sensitivity of the muscles in the back Vary as the distance of the prong gets less.

Gluteus medias muscle (sensitive)

Apparatus:

I think that the larger the muscle the less sensitive it is likely to be this is because the nerve endings will be further apart so the muscles will not be able to detect the smaller distances of the prongs. Whereas the smaller muscles will have nerve endings closer to each other and I think they will be a lot more sensitive to the prongs. I think this is going to happen because there are a certain number of nerve endings spread throughout your muscles therefore the larger muscles will need to have greater numbers of nerve endings to be as sensitive as the smaller muscles with less nerve endings. My predictions to how sensitive the muscles are shown in brackets in the picture above. I will be using a hair pin and a ruler as the hair pin does the testing and the ruler is to measure the distance of the prongs of the hair pin, I will also need 10 subjects to test 5 male and 5 female to make all the results valid. Due to preliminary work I have found that the larger the muscle the less sensitive the muscle is.

To make sure that all the results are valid I have to use the same amount of pressure on each test so that there is no discrepancy in the results therefore the subjects being tested will all be subdued to the same pressure therefore the result will totally rely on the sensitivity of the muscle. The pressure on the subjects will not be great so that the subject can feel pain but only just so that the subjects can detect the pressure of the hairpins.

Results:

       = wrong answer

       = correct answer

My results clearly show that the size of the muscle does affect the sensitivity of it as the Gluteus Medias muscle was a lot more sensitive than the Latissimus dorsi muscle which was very poor at detecting small distances of the prongs on the hair pin. The results came out as I had predicted but for the test to be very successful I would have needed to test more than 10 people to get a good set of results which would still not be perfect because I have no way of telling if the subjects are being truthful about the number of prongs they can feel. The results may also vary due to the size of the muscles of subject that is being tested and the positioning of the hairpins on the muscle as in certain places the hairpin would be touching more nerve endings than in other pars of the muscle and visa versa.

If a was to improve the experiments I would test more people and if I had the facilities to use a lie detector I could find out whether the subject is being truthful and also I would want to use a very precise measurement with a proper tool that is fully adjustable to within a fraction of a millimetre so that the distance between the prongs does not change with the slightest movement and that if pressure is applied the prongs do not spread