Abnormal Foot Mechanics Flashcards
When examining a patients DF what should be done at the calcaneus?
invert calcaneus as it creates a rigid lever and will avoid any oblique axis compensations (pronation)
What is the desired degrees of ankle DF in STJN?
10
Why does the foot need 10 degrees of DF in STJN during gait?
bc STJ is supinating in late midstance therefore if adequate DF is not accessible foot will begin to pronate at propulsion
What is excessive compensation?
when the motion required surpasses supportive tissue tolerance resulting in soft tissue trauma
What are two main goals during gait of foot and in what order?
- get plantar surface of calcaneus to ground by normal pronation
- get met heads to ground through forefoot
What happens to 2 goals if their is an uncompensated foot type?
RF or FF will not get into contact fully to ground
What may be a reason that pt can’t achieve either goal type?
STJ limitations, abnormal LE alignment up the chain
Can a callus pattern be diagnostic?
No, can just tell you where pts puts weight
What is normal STJ at initial contact during gait?
STJ in slight supination at HS then pronates 3-5 degrees at FF
What is normal STJ at midstance during gait?
STJ re-supinates to neutral or slight supination
What is normal STJ at propulsion during gait?
STJ continues to supinate
What are the ranges for subtalar varus?
Normal 0-4
Mild 5-6
Moderate 7-8
Severe- 9-10
Is subtalar varus more of a problem in relaxed or dynamic stance?
dynamic
What happens during gait with a compensated subtalar varus?
at IC there is increased calcaneal inversion which then leads to increased pronation to achieve goal 1-2 therefore the foot never returns to desired supination at propulsion and pushing off unstable base
What is the callus pattern for compensated subtalar varus?
2-3 met heads, MTJ unstable
Peroneus longus is unable to stabilize 1st ray so doesn’t stay down for propulsion
What are common pathologies associated with compensated ST varus?
plantar fascitis, TP tendinitis, patellafemoral dysfnx, medial knee pain, Sinus tarsai, metatarsalgia 2-3
What are treatment options for compensated subtalar varus?
control hip IR with glute work, foot intrinsics, eccentric tib post.
What are orthotic tx options for compensated ST varus?
biomehcnaical, medial rearfoot post
stability or motion control shoe
What are common characteristics of uncompensated ST varus?
hypomobile and stable foot type
What is happening during gait for an uncompensated ST varus?
increased calcaneal inversion at heel strike but there is decreased STJ motion for pronation therefore pressure remains lateral through midstance and only shift medial through heel rise
What is callus pattern of uncompensated ST varus?
lateral border of foot, 5th MET head
What are common pathologies associated with uncompensated ST varus?
proximal sx as theyre unable to attenuate shock well, lateral ankle sprains, “pump bump”, medial ankle joint pain, stress fractures, 5th MET fx (jones or dancer’s)
Why might someone with uncompensated ST varus have medial ankle pain?
due to STJ compression bc they are tryin to pronate but are unable to as they run out of mobility
What are tx options for uncompensated ST varus?
restore mobility in all joint ST, TCJ, MT
What are orthotic options for uncompensated ST varus?
Accomodative device, cushion device as they need help shock absoprtion
What are characteristics of compensated forefoot varus?
RF is ok but FF is hypermobile, classic footflat
What happens during the gait cycle with compensated forefoot varus?
STJ in slight supination at IC, but due to increased FF mobility the foot continues to pronate and remains pronated at propulsion
How is supination affected by pronation?
how well you supinate is determined by how well you can control pronation
What is the callus pattern of compensated forefoot varus?
2-3 met heads, PL unable to stabilize 1st ray, pinched callus at medial hallux due to increased toe out
Why is compensated forefoot varus considered the most destructive foot type?
bc you are pronated through late midstance
tibia is IR when knee needs to extend, causing extended femur IR predisposing someone for lateral knee pain
What are common pathologies associated with compensated forefoot varus?
MT joint destruction, 2nd MET stress fx, Post tib dysfnx, achilles tendinitis (trying to help TP control pronation), bunion
What are tx options for compensated forefoot varus?
control pronation, gastroc soleus flexibility, foot intrinsics, balance activities
What are orthotics options for compensated forefoot varus?
biomechanical device, medial FF posting
footwear- motion control
What are characteristics of uncompensated forefoot varus?
1st ray stays up, due to antalgic compensation, hypomobile foot type
What happends during gait with an uncompensated forefoot varus?
slight supination at HS, pronates but less than normal but due to limited STJ mobility unable to fully pronate and stays pronated during propulsion
What is callus pattern of uncompensated foot type?
lateral border of foot and 5th met
What are tx goals of uncompensated forefoot varus?
restore mobility, control GRF, provide cushion to encourage pronation, kinetic chain tx
What are orthotic goals for uncompensated forefoot varus?
accomodative, cushion shoe
What are characteristics of forefoot valgus?
1-5th everted, with likely PF 1st ray, neither compensated or uncompensated but acts as uncompensated, supinatory foot type with high arch
What happens during gait with forefoot valgus?
STJ pronates at HS but is limited by PF 1st ray, which leads to earlier supination at midstance but then at propulsion leads to STJ pronation to bring weight medial
What is callus pattern for forefoot valgus?
1st met head as premature loading
5th met head - pivots to shift weight to CL foot
What are common pathologies for forefoot valgus?
chronic lateral ankle sprains, PL tendinitis (overusing in stabilizing 1st ray), pelvic girdle dysfunction- unable to attenuate shock well , posterolateral knee pain
What are tx interventions for forefoot valgus?
encourage supination and pronation, neuro re-ed (adapt to uneven terrain)
What is orthotic therapy for forefoot valgus?
flexible biomechanical device, 0 degree rearfoot post, lateral forefoot post (reduced amount to re supinate), 1st ray cut out
cushion shoe
What is ankle equinus?
less than 10 degrees of DF at STJN
How do you use ankle equinus?
prone DF with knee flexed (soleus) or knee extended (gastroc)
What if pain is felt with overpressure during DF assessment?
posterior= muscle
anterior= joint
What are the 2 main factors of compensations if a pt has decreased ankle equinus?
- stable MTJ- early heel rise
2. unstable/flexible MTJ- excessive pronation at midstance through MTJ oblique axis
What are biomechanical adaptions from ankle equinus?
HIP ER, genu recurvartum, decreases step length
What is foot motion during gait with ankle equinus?
normal STJ pronation at contact, but at midstance TCJ hits end range so then excessive pronation occurs at oblique axis, therefore continued pronation at propulsion
What is calllus pattern of ankle equinus?
2-3 MET HEADS DUE TO HYPERMOBILITY
What are common pathologies associated with ankle equinus?
metatarsalgia due to premature loading, TP and achilles tendinitis (excessive tension)
What are tx interventions for ankle equinus?
TCJ mobility, G/S stretching (dont let pts pronate), heel lift if in acute pain
