Trunk Stability Vs. Pelvis Stability

MPI MPI Non‐specific low back pain Biomechanical Factors Related to Activity related Mechanical Low Back Pain • “My back tightens up when I run”

• “I get low back pain when I walk Christopher M. Powers, PhD, PT, FACSM, FAPTA distances”

Division Biokinesiology & Physical Therapy • “ I get back pain when I squat Co‐Director, Musculoskeletal Biomechanics Research Laboratory and/or lift” University of Southern California • Probable tissue sources • Facet joints Movement Performance Institute • Paraspinal muscles Los Angeles, CA

MPI MPI Lumbar Facet Joints Muscular Anatomy

• Essential for spinal stability

• Distributes forces across the • Support and stabilize spinal column the spinal column – Load sharing • Deep layers anchored to • Facet compression caused by the pelvis – Lateral flexion – Rotation

MPI MPI Trunk Stabilizers

Trunk Stability vs. Trunk Muscles Pelvis Stability Abdominals Obliques Paraspinals

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA MPI MPI Pelvis Stabilizers Pelvis or Trunk Instability?

Hip/Pelvis Muscles

Gluteus Medius Gluteus Maximus

Courtesy of John Popovich

MPI MPI

Excessive Spinal Motion as a Compensation for Hip Abductor weakness

Uncompensated Compensated

MPI MPI Hip Abductor Weakness & Lateral Trunk Lean

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA MPI MPI Left Sided Low Back Pain & Running

Uncompensated Compensated

MPI MPI Hip Abductor Weakness “Transient” Scoliosis Paraspinal/Quadratus Lumborum Muscle Overuse

MPI MPI Facet Joint Degeneration on “Transient” Scoliosis Side of Compression

Porterfield, JA and DeRosa, C. Mechanical Low Back Pain. 1998.

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA MPI MPI Lumbopelvic Landing Kinematics & EMG in Lumbar Facet Joint & Intervertebral Disc Women with Contrasting hip Strength Loading During Simulated Pelvic Obliquity Popovich & Kulig, Med Sci Sports Exerc, 2012 Popovich et al., Spine, 2013

• Greater frontal and transverse plane trunk • Increased facet excursions in persons loading during with hip abductor simulated pelvic weakness obliquity in the frontal and transverse planes

• Greater activation of erector spinae and • Intradiscal pressure external obliques in highest in lateral persons with hip flexion abductor weakness

MPI MPI Lateral Trunk Lean Lateral Trunk Lean

• Causes – Compensatory for hip abductor weakness

• Penalties – Ipsilateral facet joint compression – Contralateral paraspinal muscle overuse

MPI MPI What is the True “Core” Gluteus Medius of the Problem?

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA MPI MPI Gluteus Maximus: Before After “The Tri‐planar Muscle” Treatment Treatment

• Extensor

• Abductor

• External Rotator

MPI MPI Hip Extension‐Terminal Stance

Excessive Pelvis Motions as a Compensation for Hip Flexor Tightness

MPI MPI Hip Extension‐Toe Off Hip Flexor Tightness & Low Back Pain

• Excessive pelvis motions to compensate for hip flexor tightness – Anterior pelvic tilt – Transverse plane pelvic rotation

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA MPI MPI Compensatory Anterior Pelvic Tilt

MPI MPI Low Back Pain With Walking Inadequate Hip/Knee Flexion Loading Response

• Inadequate shock absorption • Potential Causes • Backward trunk lean – Quadriceps weakness – Hip extensor • Pelvic drop/lateral trunk lean weakness – Muscle or joint pain (avoidance) • Inadequate hip extension

MPI MPI What are the consequences of Extended Trunk impaired lower extremity shock Loading Response absorption on the spine? • Causes • Disc Compression? – Compensatory for hip extensor weakness

• Increased facet • Penalties loading? – Increased lumbar lordosis – Increased facet compression • SI joint dysfunction?

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA MPI MPI Kinetics & Muscle Control: Excessive Pelvic Drop Loading Response Stance Phases •Hip flexion moment • Causes –Glut max – Hip abductor weakness –Hamstrings • Penalties •Knee flexion moment – Increased spine stress –Quadriceps – Facet joint compression – Muscle overuse •Ankle plantarflexion – Paraspinals moment – Quadratus Lumborum –Dorsiflexors

MPI MPI Inadequate Hip/Knee Extension Limited Stride Length Terminal Stance Is Gluteus Maximus Weakness Related to Contralateral Hip Flexor Tightness? • Causes – Hip flexor tightness

• Penalties – Reduced stride length – Compensatory pelvis motions

MPI MPI Limited Hip & Knee Flexion Low Back Pain With Running Deceleration • Causes • Inadequate shock absorption – Weakness of knee extensors and/or hip extensors • Backward trunk lean • Penalties • Pelvic drop/Lateral trunk lean – Decreased shock absorption – Increased spine • Inadequate hip extension compression

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA MPI MPI Extended Trunk Excessive Pelvic Drop Deceleration Deceleration

• Causes • Causes – Compensatory for hip – Hip abductor weakness extensor weakness • Penalties • Penalties – Facet joint compression – Increased lumbar lordosis – Compensatory – Increased facet paraspinal activity compression

MPI MPI Lateral Trunk Lean Limited Hip Extension Toe off

• Causes • Causes – Compensatory for hip – Hip flexor tightness abductor weakness • Penalties • Penalties – Increased vertical – Ipsilateral facet joint COM displacement compression – Compensatory pelvis – Contralateral paraspinal rotation, anterior tilt muscle overuse & lumbar extension

MPI MPI

Hip Strategy vs. Low Back Pain With Knee Strategy Squatting & Lifting Implications for Trunk Posture

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA MPI MPI Hip Strategy: Squat Knee Strategy: Squat

MPI MPI Hip Strategy: Lift Knee Strategy: Lifting

MPI MPI

Knee Strategy: Lifting Hip vs Spine Extension

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA MPI Treatment Paradigm

• Flexibility

• Activation

• Strengthening

• Movement re‐education

CSM 2014 Christopher M. Powers PhD, PT, FACSM, FAPTA