The Problem An Innovative Approach to the Injured Runner Irene S. Davis, PhD, PT, FAPTA, FACSM Director, Spaulding National Running Center Harvard Medical School Healthy People 2020 Initiative 76% runners will sustain an injury within a given year 46% will be recurrences Lower Quarter Assessment threshold! Dosage Mechanics Structure! Postural Observations Postural Observations Pelvic Deviations Femoral Deviations Knee Deviations Patellar Position Tibial Deviations Calcaneal Position Midfoot Position Hallux Position Foot Angle Arch Height 1
Single Leg Squat Common Deviations of SLS NL: Knee over 2nd toe Common Deviations of SLS Foot Structure Feet are one of the most variable anatomic structures between individuals They come in a variety of shapes and alignments 2
Functions of the Foot Foot is a complex structure! 26 bones, 33 jts, 112 ligs, 20+ muscles Forefoot - MT and phalanges Midfoot - Midtarsal Jt (TN+CC) Base of Support Mobile Adapter Rigid Lever Rearfoot - Ankle + Subtalar Jts Terminology Triplane motions Terminology Pronation Supination Dorsiflexion Eversion Abduction Plantarflexion Inversion Adduction Describe movement Valgus Varus Describe position Terminology Open Vs. Closed Chain Motion Open Chain Motion that occurs when the distal segment is free to move Closed Chain Motion that occurs when the distal segment is fixed Open chain DF Talus on Tibia Open chain Pronation Calcaneus on Talus Closed chain DF Tibia on talus Closed chain Pronation Talus on Calcaneus 3
Gastroc-Soleus Midfoot pronation or Rearfoot pronation NL: 10 o o Limited Dorsiflexion NL: 20 Plantar fasciitis Rearfoot Position Normal Rearfoot and Forefoot Alignment undercompensation overcompensation Normal compensation Normal 20 deg INV/ 10 deg EV Forefoot to Rearfoot Position Forefoot to Rearfoot Position undercompensation undercompensation Load lat Forefoot Load med Forefoot overcompensation overcompensation Rearft eversion Rearft inversion Load med Forefoot Load lat Forefoot 4
3 2. 5 2 1. 5 1 0. 5 0 2 0-2 - 4-6 - 8-1 0 8 6 4 Midfoot Mobility Arch Assessment Typically: Planus = Hypermobile Cavus = Hypomobile Arch Ht and Injury Arch Height and Mechanics 60 50 Frequency 40 30 20 10 0 High Arch Low Arch Medial Lateral Soft Tissue Bony Selected Injuries HA LA Plantar Fasciitis 8 5 5 th Met Stress Fx 3 0 Post Tib Tendinitis 1 3 Lateral Ankle Sprain 8 1 General Knee Pain 0 8 Patellar Tendinitis 3 6 EV Degrees Rearfoot EV % Stance FL - 54 HA LA HA LA EV exc 11.9 14.0 FL exc 32.7 37.0 EV vel 166.0 219.3 Degrees - 6-1 8-3 0-4 2 Knee FL % Stance Low Arch had higher excursions and velocities Force Results VGRF Summary Body Weights HA LA VLR (bw/s) 62.5 52.1 Stiffness (N/m) 7.1 6.46 These data suggest that arch structure does influence lower extremity mechanics, as well as the risk for injury % S t a n c e High Arch had higher loadrates and leg stiffness 5
Morton s Foot Structure Morton s Foot Structure NL: <8-10 mm 2nd Metatarsalgia First Ray Position/ Mobility Plantarflexed rigid - 1st metatarsalgia* flexible - usually no problem Hallux Limitus* Hypermobile 2nd metarsalgia Hypomobile 1st metarsalgia* * Compensate by inverting late in stance to minimize loading under the 1st * Compensate by inverting late in stance to minimize loading under the 1st Leg Length Causes of Pronation NL: < 10 mm Compensation Pronation - Long Supination - Short Pes Planus FF Varus Rf Varus LL Discrepancy Mortons Foot Genu Valgus Hip IR 6
Foot Problems Associated with Pronation Causes of Supination Plantar Fasciitis Posterior Tibialis Tendinitis Achilles Tendinitis Sesmoiditis Stress Fractures Pes Cavus FF Valgus Rf Varus LL Discrepancy Genu Varus Hip ER Problems Associated with Supination Standing Alignment Stress Fractures of 5th MT Lateral Instability Recurrent Ankle Sprains Peroneal Tendinitis Heel ~ 0-5 deg Leg ~ 5-7 deg Rearfoot ~ 10 deg Q-Angle Tibial Varum NL: 10 o - 15 o 7
Retropatellar Assessment Patellar Position Patellar Tracking Hamstrings NL: 70 o - 90 o Tibial Torsion NL: 15 o 20 o ER External Tibial Torsion Internal Tibial Torsion 8
IT Band Flexibility Hip IR/ER NL: ER-45 o IR-35 o Hip/Core Strength Knee alignment in the frontal and transverse planes is controlled by the hip musculature Leg Lowering Test Hip ABD + ER Strength 9
Shoes Provide Much Insight Hip Drop Hip Add and IR If not shoes, then feet Summary Structure is 1 factor in a multifactorial problem Structure is a non-modifiable risk factor The greater the structural deviation, the greater the chance for injury 10