Regression analysis for the influence one result has on the results of another test

Hi There,

My name is Jordan and I’m a physiotherapist working in London. I have taken over study from a colleague and have been given the data and don’t know what to do with it. I’ve spent hours watching youtube tutorials on excel and spss regression analysis etc. but I’m still at a loss.

Basically I am trying to determine if the degree of muscle tightness at 2 points in the leg ( ankle and hip ) have an impact on 2 functional tests we carry out. I am hoping to prove that as the tightness at the ankle increases the the scores decrease, followed by the fact that the hip does not affect either scores and we can therefore stop measuring it.

I have data from approximately 40 subjects over a 2 year period. Some subjects have carried out more visits than others.

I would also like to add age in as a variable to see if it effects the scores alongside the muscle tightness.

I didn’t know if it was possible to correlate all visits for the subjects or should I just use 1 visit per subject?

I’m not sure if that makes sense.

I'm sorry of my request sounds amature as i said I have a very basic knowledge but a very real deadline and expectation on my shoulders.

Any help will be gratefully received.

Thank you