Biomechanics Joint Torque Calculator

Enter force, moment arm length, and angle to instantly calculate joint torque for biomechanics or physical therapy analysis.

Inputs

Enter the three values that define the torque scenario.

N

1 lb ≈ 4.448 N

m

1 cm = 0.01 m

°

Angle between force vector and body segment (0–360°)

Joint Torque

—
Newton-meters (N·m)

Formula

τ = F × d × sin(θ)
τ = Torque (N·m)
F = Applied Force (N)
d = Moment Arm Length (m)
θ = Angle between force and segment (°)

Torque vs. Angle (current F & d)

Torque peaks at 90° where sin(θ) = 1

Summary

Enter force, moment arm length, and angle to instantly calculate joint torque for biomechanics or physical therapy analysis.

How it works

  1. Enter the applied force in Newtons (N).
  2. Enter the moment arm length in meters (m) — the perpendicular distance from the joint axis to the line of force.
  3. Enter the angle (degrees) between the force vector and the segment.
  4. Click Calculate to get the torque in Newton-meters (N·m).
  5. Review the formula breakdown and adjust inputs for different scenarios.

Use cases

  • Analyze shoulder, elbow, or knee joint loading during rehabilitation exercises.
  • Compare torque demands across different exercise positions or joint angles.
  • Estimate muscle torque requirements for a given external load.
  • Teach biomechanics concepts in physical therapy or kinesiology courses.
  • Assess joint stress in occupational ergonomics assessments.
  • Optimize sporting technique by minimizing harmful joint torques.
  • Plan progressive loading in post-surgical rehabilitation protocols.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu