The Physics of Training
Thoughts from: Dr. Michael Reinhardt, DPT, OCS: Performance Physical Therapist, Resilient Performance & PT & R2P Academy Instructor
Training, rehab, and performance all come down to force application.
When looking through the lens of training, we are most often trying to increase local force-generating abilities at specific joints and/or tissues.
Understanding the basic relationship between joint torque (the rotational force generated around a joint) and moment arms can be highly influential when selecting exercises and making technical modifications.
The pictures above exemplify the considerable differences in the hip and knee moment arms experienced across hinging and squatting movements. In other words, hinging movements create large muscular and joint demands on the hips because of the increased length of the lever compared to where the force must be applied (through the feet/ground).
Alternatively, upright squatting and lunging movements create a much larger moment arm and muscular demands at the knee as compared to the hip. This is because of the alteration in the location of the body’s center of mass relative to the loads being lifted.
With hinging, the center of mass must move posteriorly. With squatting, the center of mass should stay centered overtop the feet, resulting in greater mechanical demands on the knee extensors.
The key consideration here is that any exercise can be selected and modified based on the desired physical loads we are hoping to generate. This is particularly useful insight when the intent is to load specific joints or muscles, as is often the case in rehabilitation and performance settings.
Exercises by themselves are just blunt tools. Intelligent application is the secret sauce.
Follow Mike on Instagram for more!
____________________________
Ready 2 Level up in Sports & Performance Physical Therapy? Start with the self-paced Foundations of Sports Rehab, where Dr. Reinhardt and the team lay the ground work as you lead your clients from rehab 2 performance. Approved for up to 9 Hours of CEUs for Physical Therapists. Learn more and get started HERE