Cory et al investigated three varied, but similar positions of a forward lunge. The three positions can be seen here.
What they found was the lead limb position influence both the lead and hind limb stress during the forward lunge. With a forward trunk and forward lower limb positions, an increased stress was reported on the forward limb. However, the stress on the hind limb as reduced compared to the FV and VV positions. The opposite was found during the other trunk and limb positions during the lunge. When the front leg was maintained as more vertical the force on the front knee limb was reduced, but at the expense of the rear limb which showed increased joint reaction forces during the FV and VV positions.
A recent published article in JOSPT in Jan 2017 reported altered PF stress during different types of shank and trunk positions during a lunge. Here are some visual feedback options using MG to standardize the performance mechanics for your patient.
These results can yield clinical considerations of varying the lower leg and trunk positions during the forward lunge exercise to either avoid or achieve a desired performance or reaction force at the knee joint. Adding visual feedback to the trunk or the lower limb during the lunge may assist both the clinician and the client in achieving and maintaining the desired body position.
One option is placing the Motion Guidance visual feedback unit at the lower leg:
1. ) Hoffman, Cory et al. Trunk and Shank Position Influences Patellofemoral Joint Stress in the Lean and Trail Limbs During the Forward Lunge Exercise. JOSPT VOl 47, No. pp 31-39, 1, Jan 201