Convex on Concave

Rules

• Convex on Concave- roll and slide occur in OPPOSITE directions

• Concave on Convex- roll and slide occur in the same direction

Temporomandibular joint

• Convex on concave

  • Mandible head (convex) on mandibular fossa (concave)

• Elevation (closing)- Roll anterior, slides posterior

• Depression (opening)- Roll posterior, slides anterior

Sternoclavicular joint

• Saddle joint (two planes)

  • Convex on Concave- clavicle on sternum in elevation/ depression (frontal plane)

  • Concave on Convex- clavicle on sternum in protraction/ retraction (sagittal plane)

• Elevation- Rolls superior, slides inferior

• Depression- Rolls inferior, slides superior

• Protraction- Rolls Anterior, slides anterior

• Retraction- Rolls Posterior, slides posterior

Glenohumeral Joint

• Convex on Concave

  • Humerus on Glenoid Fossa

• Flexion- Rolls anterior, slides posterior

• Extension- Rolls posterior, slides anterior

• Abduction- Rolls Superior, slides inferior

• Adduction- Rolls inferior, slides superior

• Internal (medial) rotation - Rolls anterior, slides posterior

• External (lateral) rotation- Rolls posterior, slides anterior

• Horizontal abduction- Rolls posterior, slides anterior

• Horizontal adduction- Rolls anterior, slides posterior

Radiohumeral joint

• Concave on Convex

  • concave radial head on convex capitulum

• Flexion- Rolls anterior, slides anterior

• Extension- Rolls posterior, slides posterior

Proximal radioulnar joint

• Convex on concave

  • Radius on ulna

• Pronation- Rolls anterior, slides superior

• Supination- Rolls posterior, slides superior

Distal radial ulnar joint

• Concave on convex

  • Radius on ulna

• Pronation- Rolls anterior, slides anterior

• Supination- Rolls posterior, slides posterior

wrist joint (radiocarpal joint

• Convex on concave

  • Proximal carpal row on radius

• Flexion- Rolls anterior, slides posterior

• Extension- Rolls posterior, slides anterior

• Ulnar deviation- Rolls medial, slides lateral

• Radial deviation- Rolls lateral, slides medial

Metacarpophalangeal joint

• Concave on convex

  • Proximal phalanx on metacarpals

• Flexion- Rolls anterior, slides anterior

• Extension- Rolls posterior, slides posterior

• Abduction- Rolls lateral, slides lateral

• Adduction- Rolls medial, slides medial

Thumb (on Trapezium)

• Saddle joint (two planes)

  • Convex on Concave- proximal metacarpal on trapezium in abduction/ addiction

  • Concave on Convex- trapezium on proximal metacarpal in flexion/ extension

• Flexion- Rolls ulnar, slides ulnar

• Extension- Rolls radial, slides radial

• Abduction- Rolls volar, slides dorsal

• Adduction- Rolls dorsal, slides volar

Hip Joint

• Convex on concave

  • Femur on acetabulum

• Flexion- Rolls anterior, slides posterior

• Extension- Rolls posterior, slides anterior

• Abduction- Rolls lateral/ superior, slides inferior

• Adduction- Rolls medial/ inferior, slides superior

• Internal rotation- Rolls anterior, slides posterior

• External rotation- Rolls posterior, slides anterior

Knee/ Tibiofemoral joint

• Concave on convex in open chain

  • Tibia on femur

• Convex on concave in closed chain

  • Femur on tibia

• OKC Flexion- Rolls posterior, slides posterior

• OKC Extension- Rolls anterior, slides anterior

• CKC Flexon- Rolls posterior, slides anterior

• CKC Extension- Rolls anterior, slides posterior

Patellofemoral joint

• Flexion- Slides inferior

• Extension- Slides superior

Talocrural joint

• Convex on concave

  • Talus on Tibia and Fibula

• Dorsiflexion- Rolls anterior, slides posterior

• Plantarflexion- Rolls posterior, slides anterior

Subtalar Joint

• Convex on concave

• Inversion- Rolls medial, slides lateral

• Eversion- Rolls lateral, slides medial