**1. The problem statement, all variables and given/known data**

**2. Relevant equations**

**3. The attempt at a solution**

I have tried solving this by assuming the vector sum of three forces to be zero.

But evidently I got the wrong answer. I am going to try using the fact that the resultant of the moments about any point is zero to solve this but I'd like to know why the working above got me the wrong answer.

Another thing I'm confused is that why do we not need to take into account the weight of the person? Is the weight included in the compression (force R) of the tibia?