The Monday Memo
September 10, 2018 PITT DPT STUDENTS
Deadbug Anti-Extension Progression:
Moment Arms & Torque Production
Core stability is a hot topic in the world of physical therapy for good reason. Today’s video memo provides you with an example anti-extension progression, beginning with a basic, day 1 pelvic control drill (1⃣), & progressing towards weighted, higher level versions (4⃣/5⃣). Check out the video below and then tune in for a follow-up message below!
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EPISODE 212 | Trunk Anti-Extension Progression: Deadbug Variations . ▪️I really enjoy posting content similar to today’s video. . Why? . Because it’s JAM-PACKED with conceptual information. . This video provides you with a fairly complete anti-extension progression, beginning with a basic, day 1 pelvic control drill (1️⃣), & progresses you towards weighted, higher level versions (4️⃣/5️⃣) that I’ve used to challenge professional athletes. . I’ll post a follow up detailing each exercise, but let’s use today to touch on an important concept: TORQUE PRODUCTION & MOMENT ARMS! . . . 🤓TORQUE PRODUCTION & MOMENT ARMS! . Revisiting physics, we know that you can create more torque by using a wrench w/ a longer handle. . In essence, a longer wrench has a longer moment arm, which means a relative amount of torque can be produced w/ less force. . We can apply this to single-leg lowers & deadbugs by understanding that our leg is the moment arm upon which gravity exerts a force to produce torque at the hip & up the chain. . In response, we need to produce an equal amount of force w/ our abdominals to maintain spinal positioning. . . 💡When we straighten our knee or lower our leg further, we’re effectively increasing the moment arm, & since gravity pulls w/ the same amount of force, our abdominals must contract harder & produce more force to maintain the same position. . We can take it further by including our arms or lowering both legs at the same time. . . 💡Our arms add another element that gravity uses to create more extension force & focuses more on controlling rib cage, rather than pelvic, positioning. . Lowering both legs at once inc the mass & eliminates the rotational component created by the unilateral Deadbug. . . . 🔥This is an incredibly important concept to understand & can be applied to ALL therapeutic exercise. . It’s this kind of knowledge that allows you to adjust for the trainee in front of you & work w/ a wider range of patients/clients. . . ▪️Questions, comments, concerns? Drop a line in the section below! . Was this information helpful? Tag a friend & help spread the word! . #StoutTraining #DPTstudent #Physics . @stoutpgh @clinicalathlete @perform_better
It’s important to understand the underlying concept that allows this progression to be so effective: TORQUE PRODUCTION & MOMENT ARMS!
Revisiting physics, we know that TORQUE is a product of the FORCE APPLIED and the distance from the point of force application and the axis of rotation, or the MOMENT ARM. Think of a wrench! A wrench with a longer handle allows you to create more torque with the same amount of force!
We can apply this to single-leg lowers & deadbugs by understanding that our leg is the moment arm upon which gravity acts. This produces torque applied at the hip which is transmitted up the chain. In response, our musculature must produce an equal amount of force in order to maintain lumbopelvic position.
➢ When we straighten our knee or lower our leg further, we’re effectively increasing the moment arm, and our trunk musculature must contract harder & produce more force to maintain the same position.
We can take this further by including our arms or lowering both legs at the same time!. .
➢ Our arms add another point at which gravity act to create more extension force. The arms are a part of our upper quarter shifting the focus more towards controlling rib cage, rather than pelvic, positioning.
Lowering both legs at once increase the mass and eliminates the rotational component created when performing the unilateral Deadbug!
This is an important concept to understand and some critical thinking can help you apply it to ALL therapeutic exercise. It’s this kind of knowledge that allows you to adjust for the trainee in front of you, find success with a wider range of individuals, and enhance your abilities as a provider!