I have taken a course in Medical device design engineering and went back to try and retrain to get back into the jobs market. However since starting this course i have taken a very keen interest in maths. I have a small problem i keep getting caught on and wondering if anyone can guide me on how i would start off working out forces on an human arm at different angles from 0 to 135 degrees. i have to include muscles say biceps I am using a point of mo from a pivot point on an elbow prosthesis implant between the humerus and Ulna.
I keep getting brain dead at a certain point of the equation. I can do the free body diagram etc. and if anyone can walk me through the next steps i would very much appreciate it. I am over 30 years out of school and thinking this is basic maths for those still at Uni today. Thank you in advance for any help with this.
If you can set me on the road working out say 5 degrees and then 10 degrees would be great. neglect the weight of the arm. and use a 2kg weight on the hand . thank you in advance.
please explain in lay man terms as i am a little thick

best regards