Dynamic/Static Tissues Static Plantar fascia biomechanical windlass mechanism intrinsic muscles stabilize metatarsophalangeal (MP) toe joints Weight on whole foot - MP toe joints straight Plantar fascia and intrinsic muscles relaxed not engaged Standing midfoot collapses flatfoot pronation Walking midfoot collapses during most of the stance phase of walking Safety/Injury Balance/Imbalance-Falls Resistance/Susceptibility Forces: Accelerations/Decelerations Joints: Stability/Instability Traction/Impingement Muscles: Strength/Weakness Energy Efficiency Stride length/step cadence Braking Gliding Bounce/Elasticity Resonance Muscle work Performance Dynamic/Static Posture Adaptation Dynamic Weight on ball of foot heel off the ground - MP toe joints dorsiflexed Plantar fascia and intrinsic muscles - engaged Standing midfoot elevates Walking midfoot elevates during most of the stance phase of walking
Evolutionary Biology Flatfeet None in the fossil record Plantar fascia Unique to humans Biped locomotion
Plantar Fascia Biomechanics Windlass function Bony Arch Support Bone and joint configuration Plantar ligaments Intrinsic muscles Plantar fascia
Dynamic Dynamic /Standing Plantar fascia/intrinsic muscles engaged Medial longitudinal arch dynamically elevates Static /Standing Plantar fascia and intrinsic muscles relaxed Medial longitudinal arch dynamically collapses
Dynamic/Static Plantar Fascia and Intrinsic Muscle Engagement? (DW/HBW) (HTW) Dynamic DW/HBW Heel lift-off early Plantar fascia and intrinsic muscles engaged through most of the stance phase of gait Static HTW Heel lift-off late Plantar fascia and intrinsic muscles are not engaged through most of the stance phase of gait
Standing Static and Dynamic Static Standing Dynamic Standing Dynamic Standing COM located over ball of foot Muscles in LE all active Core muscles - active intrinsic muscles - active Plantar fascia - active Static Standing COM located over midfoot Muscles in LE some active Core muscles mostly inactive intrinsic muscles - inactive Plantar fascia - inactive
Dynamic Feet Appearance Strong Intrinsic Muscles Gap between great toe and 2 nd toe Extensor tendons not visible
Static Feet Appearance Intrinsic Muscle Atrophy Prominent extensor tendons Claw toes
Shoes/wear/Orthotics Today
MINIMALIST SHOES
Unshod Walking Habitual Barefoot Walking (HBW) HBW HBW HBW = Dynamic walking foot: HBW engages the plantar facia and intrinsic muscles of the foot during the majority of the stance phase of walking. A plantigrade foot is created dynamically with active midfoot support and arch elevation. The dynamic foot is energy efficient, and injury resistant. Dynamic Walking foot
Shod Walking Deliberate Walking (DW) DW DW DW = Dynamic walking foot: DW simulates HBW. HBW engages the plantar facia and intrinsic muscles of the foot during the majority of the stance phase of walking. A plantigrade foot is created dynamically with active midfoot support and arch elevation. This occurs regardless of the passive shoe support. The dynamic foot is energy efficient, and injury resistant. Dynamic foot
Shod Walking Heel-toe Walking (HTW) HTW HTW HTW = Static walking foot: HTW does not engage the plantar facia and intrinsic muscles of the foot during the majority of the stance phase of walking. Without dynamic midfoot support, arch collapse can occur in the static foot. Maintaining a plantigrade foot position and posture becomes shoe dependent. Static foot
Shod Walking HTW + Proper Shoes HTW Proper Shoes HTW Proper Shoes HTW = Static walking foot: HTW does not engage the plantar facia and intrinsic muscles of the foot during the majority of the stance phase of walking. Without dynamic midfoot support, arch collapse can occur. Proper shoes can restore the foot to a plantigrade position and posture by passively supporting the static walking foot. Static Plantigrade foot
Shod Walking HTW + Improper Shoes HTW Improper Shoes HTW Improper Shoes HTW = Static walking foot: HTW does not engage the plantar facia and intrinsic muscles of the foot during the majority of the stance phase of walking. Without dynamic midfoot support arch collapse can occur. Improper shoes lead to a non-plantigrade, passive foot position and posture which predisposes the foot to energy inefficiency and injury susceptibility. Static Nonplantigrade foot
Shod Walking HTW + Minimalist Shoes HTW Minimalist Shoes HTW Minimalist Shoes HTW = Static walking foot: HTW does not engage the plantar facia and intrinsic muscles of the foot during the majority of the stance phase of walking. Without dynamic midfoot support arch collapse can occur. Minimalist shoes lead to a non-plantigrade, passive foot position and posture which predisposes the foot to energy inefficiency and injury susceptibility. Static Nonplantigrade foot
Shod Walking DW + Minimalist Shoes DW Minimalist Shoes DW Minimalist Shoes DW = Dynamic walking foot: DW simulates HBW. HBW engages the plantar facia and intrinsic muscles of the foot during the majority of the stance phase of walking. The walking foot behaves dynamically and the midfoot elevates. A plantigrade foot is created dynamically with active midfoot support and arch elevation. Minimalist shoes facilitate an energy efficient and injury resistant foot position and posture. Dynamic Plantigrade
Uses a Dynamic foot Painful to heel strike Facilitates DW/HBW Transition period Reduced MSK injury if walking and running gait changes MINIMALIST SHOES