Foot mechanics & implications on training, posture and movement

Transcription

1 Foot mechanics & implications on training, posture and movement Three Arches Three Arches These arches are not reciprocal. When the foot pronates ALL arches should fall. If the medial arch falls and the lateral arch rises we have a problem Three arches designed to work together as a team These three arches form a TRIPOD The tripod forms the shape of the Base of Support of each individual foot It creates the base through which the FMM curve will travel SHIFT PROPULSION TRANSITION STRIKE SUSPENSION Keystones Arch Profiling Neutral STJ & Medial and lateral joint gapping High%Arch%profile%:%supinated% %S6ff%or%flexible?% Medium%Arch%:%neutral% %S6ff%or%mobile?% Low%arch%profile%:%pronated% %S6ff%or%flexible?% T Second cuneiform is the COM for the foot. Movement in one keystone couples with movement in all. The keystones (as with all motion) should be encouraged to experience movement away from, back to and beyond their centre position. Pes%Cavus% % Pes% centered % % Pes%planus% N" C" Neutral(foot:(no(gapping(of(the(talo1naviular(joint(on(either(side(of(the(head(of(the(talus( High(arch(foot:(gapping(on(the(lateral(aspect(of(the(head(of(the(talus( Low(arch(foot:(gapping(on(the(medial(aspect(of(the(head(of(the(talus(

2 STJ axis Mobile Adaptor - Rigid Lever Pronation mechanics Pronation mechanics Supination mechanics Compromised posture brings stability through the muscle system Organised structure brings stability through the joint system Joints ACT One should accompany the other. Muscles REACT FUNCTION STRUCTURE Rearfoot motion Rearfoot motion Rear View - Frontal plane Talo-crural joint: 1-dimensional Plantar flexion / Dorsiflexion Structure Pronation Supination Calcaneous / Talo-Crural Talus Sagittal TCJ DF PF Sagittal Plantar Flexing Dorsi-Flexing Pronated flat foot (pes planus) everted Supinated high arch foot (pes cavus) inverted or neutral aligned deemed ideal Sub-talar joint: 3-dimensional Plantar flexion / Dorsiflexion Eversion / Inversion Internal & External rotation Drives the Bus - Calcaneous - Calcaneous - Talus Sagittal Calcaneous PF DF Frontal Everting n/a Frontal Calcaneous EV INV Transverse Internally Rotating n/a Transverse Talus IR XR Supinated Neutral Pronated Varus Normal Valgus (Varus R/F) Neutral (Valgus R/F)

3 Varus forefoot A supinated forefoot Varus Forefoot Valgus Rearfoot Varus Forefoot Valgus Rearfoot Supinated Forefoot One accompanies the other. A varus forefoot holds it s posture through the swing phase, into Strike and delays the timing of contact at the 1st MTPJ during the Suspension phase 70% of all feet have some level of deformity: 95% of that 70% are pronators or fall into the category of varus forefoot and valgus rearfoot Pronated Rearfoot 70% of all feet have some level of deformity: 95% of that 70% are pronators or fall into the category of varus forefoot and valgus rearfoot Properties of a: Varus Forefoot / valgus rearfoot / pronating foot Varus : valgus relationships Forefoot and Rearfoot Cogs Working in opposition RearFoot ForeFoot Pronator Supinator Forefoot'ABduc-on' Forefoot'ADduc-on' Sagittal Plantar-flexing Dorsi-Flexing Frontal Everting Inverting Transverse Internally Rotating Abducting A pronating foot Supinator Pronator Rearfoot'Internal'Rota-on' &'Eversion' Rearfoot'External'Rota-on' &'Inversion'

4 Toes (might as well throw them in now) This is NOT what we want to see in gait Supination mechanics Sagittal ForeFoot Toes ForeFoot Toes Dorsi- Flexing Pronation Plantar- Flexing Plantar- Flexing Supination Dorsiflexing Toes should not spread apart and pinch together as we walk. This is the current way of describing ad and ABductions of the toes Frontal Inverting Everting Everting Inverting Transvers e Externally Rotating Abducting Adducting Adducting Toes are detailed in reference to the body s midline NOT the midline of the foot. In gait the toes should not adduct or abduct as traditionally described in anatomical terms - that is they should neither spread nor close on each other, moreover they move together as a group in response to forefoot motion. Toes follow the forefoot motions in the transverse plane and oppose the forefoot motions in the sagittal and frontal planes Rearfoot motion Transition Propulsion Phase Supinating Properties of a Valgus Forefoot Talo-crural joint: 1-dimensional Plantar flexion / Dorsiflexion Calcaneous / Talus Talo-Crural RearFoot ForeFoot Sagittal Dorsi Flexing Plantar-Flexing Sagittal Dorsi-Flexing Plantar-Flexing Sub-talar joint: 3-dimensional Plantar flexion / Dorsiflexion Eversion / Inversion Internal & External rotation Drives the Bus - Calcaneous - Calcaneous - Talus Frontal Inverting n/a Transverse Externally Rotating n/a Frontal Inverting Everting Transverse Externall Rotating Adducting A Supinating foot

5 Valgus Forefoot Valgus Forefoot Varus Rearfoot Valgus Forefoot Varus Rearfoot Pronated Forefoot One accompanies the other. Supinated Rearfoot A valgus forefoot holds it s posture through the swing phase, into Strike and increases the timing of contact at the 1st MTPJ during the Suspension phase 70% of all feet have some level of deformity: 95% of that 70% are pronators or fall into the category of varus forefoot and valgus rearfoot. By virtue of this the remaining 5% of the 70% must be supinators or fall into the category of valgus forefoot and various rearfoot. 70% of all feet have some level of deformity: 95% of that 70% are pronators or fall into the category of varus forefoot and valgus rearfoot. By virtue of this the remaining 5% of the 70% must be supinators or fall into the category of valgus forefoot and various rearfoot. Supination mechanics The Rays of the Foot The Rays of the Foot Weight bearing Minimal motion Non-weight bearing The motion in the metatarsals is required to unlock ACTUAL external rotation in the talus bone and STJ axis Rays 1-3: attaches to cuneiforms Rays 4-5: attach to cuboid Ray 1: DF on pronation (stable) Ray 2-3: DF on ankle DF (least motion) Ray 4-5: DF on supination (mobile)

6 Foot mechanics for supination 4th & 5th Ray locking mechanisms Supination: Forefoot and rearfoot joint motions Rear Foot Fore Foot Sagittal Dorsi-Flexing Plantar-Flexing Frontal Inverting Everting The motion in the metatarsals is required to unlock ACTUAL external rotation in the talus bone and STJ axis Rear Foot Calcaneous & Talus Dorsiflexion MidFoot Navicular & Cuboid Plantarflexion The Rays - a split Ray 1-3: Plantarflexion Ray 4-5: Dorsiflexion Transverse External Rotating Adducting Windlass mechanics Plantar flexion of 1st Ray coupled with dorsiflexion of 1st MTPJ Windlass cogs The Windlass Mechanism - Hicks 1954 Auto-support Mechanism for the body Dorsiflexion Test Windlass Mechanism Arrows represent gravity and correlates to foot shape in equivalent line drawing 1st MTPJ elevates Windlass(Mechanism( Externally rotates Talus Inverts calcaneous 1 st $MTPJ$elevates$ Externally$rotates$Talus$ Shortens the arch optimises the rigid lever Inverts$calcaneous$ To$tension$and$shorten$the$arch$ Three Op;mising$the$foot$ types of Windlass: Active STRIKE Reverse SUSPENSION Passive TRANSITION - PROPULSION Active Reverse Passive Plantar flexion Test

7 Effective and Ineffective coupling mechanics of the Windlass Mechanism Active Windlass Reverse Windlass Rear foot pronation with toe extension Foot flat Suspension phase Clocks pronation Rear foot supination with toe extension When you plantarflex the big toe, the arch height should reduce Passive Windlass Pronation & Supination mechanics input on knee mechanics Knee mechanics (T-plane) In suspension, pelvis, knee & tib all rotate in the same direction. Pelvis Pelvis rotates farthest and fastest Tibia rotates least and slowest Leaving femur in the middle The net outcomes of motion in thet-plane are XR at the hip and XR at the knee (same motion) Femur Tibia Foot pronation creates an XR at the knee Foot supination creates an IR at the knee

8 Flow Motion Model TRANSITION In supination, pelvis, knee & tib all rotate in the same direction. Pelvis Pronation & Supination mechanics input on hip mechanics Hip (ilio-femoral joint) mechanics Bilateral stance Pronation Supination Pelvis rotates farthest and fastest Tibia rotates least and slowest Leaving femur in the middle The net outcomes of motion in thet-plane are IR at the hip and IR at the knee (same motion) Femur Tibia S-Plane Fx Ex F-Plane Add Abd Foot supination creates an IR at the knee more least most T-Plane IR /garyalanward Hip (ilio-femoral joint) mechanics In gait Maximum Pronation Maximum Supination Pronation & Supination mechanics input on pelvic and spinal mechanics Foot / Spine anomaly? Pronation Supination S-Plane Fx Ex Pelvis S-plane Anterior Tilt Posterior Tilt F-Plane Add Abd T-Plane XR XR Spine S-plane Extension Flexion

9 Can foot mechanics help make sense of