Scenario
You are a consulting Biomedical/Industrial engineer assisting an employer in a prominent manufacturing company. An employee has torn a distal biceps tendon and is undergoing rehabilitation. A doctor and physical therapist have performed tests and determined that the injured bicep tendon should not be subjected to forces exceeding 17 N.
The employee's job requires that he routinely handles parts weighing 50-100 g. During manipulation of these parts the employee must bend their arm such that the variance in angle between the bicep muscle's line of action and forearm is 70° ≥ θ ≥ 25°. As the company engineer your team is instructed to perform a static analysis and prepare a report for submission to the employer.
Calculated Biceps Tension Procedure
Utilizing the data shown in the diagram above, perform a static analysis of the forearm to derive an equation for the magnitude of biceps tendon tension (Fm) in terms of its angle (θ) and applied load (Fh). Hint: you only need ONE rotational equilibrium equation to do this.