24/04/2026
🔴 FLAT FEET (PES PLANUS) – THE BIOMECHANICAL CASCADE
This image demonstrates how a seemingly local foot problem can create a chain reaction of dysfunction throughout the entire kinetic chain—from the foot to the spine.
🔷 WHAT IS PES PLANUS?
➟ Collapse of the medial longitudinal arch
➟ Often associated with:
▪️ Hindfoot valgus (heel eversion)
▪️ Excessive pronation
🔷 FOOT LEVEL CHANGES
➟ Flattening of the arch → loss of shock absorption
➟ Plantar fascia and intrinsic muscles become overloaded
➟ Heel shifts inward (calcaneal valgus)
📌 Result:
❗ Foot pain
❗ Poor force distribution
🔷 ANKLE & SUBTALAR JOINT
➟ Excessive pronation → subtalar joint eversion
➟ Talus moves medially and plantarward
📌 Leads to:
❗ Instability
❗ Altered load transfer
🔷 KNEE LEVEL EFFECTS
➟ Tibial internal rotation increases
➟ Promotes knee valgus (knock-knee alignment)
📌 Clinical impact:
❗ Patellofemoral pain
❗ Increased ligament stress
🔷 HIP & PELVIS COMPENSATION
➟ Femoral internal rotation
➟ Altered gluteal activation
📌 Leads to:
❗ Hip pain
❗ Reduced stability
🔷 SPINE INVOLVEMENT
➟ Pelvic tilt and asymmetrical loading
➟ Compensatory spinal curvature
📌 Result:
❗ Low back pain
❗ Postural imbalance
🔴 KEY CONCEPT – THE “KINETIC CHAIN”
A dysfunction at the foot doesn’t stay local 👇
👉 It propagates upward
👉 Affecting joints, muscles, and alignment
🔷 CLINICAL SIGNS SHOWN IN IMAGE
▪️ Collapsed arch
▪️ Heel valgus (inward tilt)
▪️ Knock-knee tendency
▪️ Abnormal shoe wear pattern
▪️ Pain distribution: foot → knee → hip → spine
🔷 MANAGEMENT PRINCIPLES
🟢 Local (Foot-focused):
▪️ Arch support / orthotics
▪️ Strengthening intrinsic foot muscles
▪️ Toe control exercises
🔵 Global (Kinetic chain):
▪️ Hip stabilizer strengthening (glutes)
▪️ Gait retraining
▪️ Postural correction
🔴 CLINICAL PEARL
➟ Always assess above and below the joint
➟ Treating only the foot without addressing the hip/core = incomplete management
✅ TAKEAWAY
Pes planus is not just a foot condition—
👉 It’s a biomechanical disorder affecting the entire body.
