This is a picture of legend Michael Jackson (MJ) doing his famous gravity-defying lean during the dance video Smooth Criminal (approx.7:05 but do enjoy the entire video unless you have the time). In the video he starts at a standing position, leans almost 45 deg from horizontal, and then stands back up again, bending about the coronal plane.

(a) Assuming MJ has a body weight of 60 kg and height of 1.75 m, and is considered quasi-static, and using as much data from“anthropometric-data.pdf” as possible, determine the tension at the erector spinae and reaction forces when holding the lean. Please state all assumptions used. If other data are used, please provide a reference from where these data were obtained from.

(b) Describe how will the analysis change if this biomechanics scenario cannot be considered quasi-static. What are the changes in the equation write down these equations.

(c) From a variables perspective, does this question provide sufficient information to solve this biomechanics scenario as a dynamic problem? Why or why not.

MJ BENDING