1st Carpometacarpal Joint

Authors

Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

• Saddle joint

Arthrokinematics

Flexion

• Concave on convex (OKC)
• Ulnar roll + Ulnar glide

Extension

• Concave on convex (OKC)
• Radial roll & glide

Adduction

• Convex-on-Concave in OKC
• Posterior/Dorsal roll + Anterior/volar glide

Abduction

• Convex-on-Concave in OKC
• Anterior/volar roll + Posterior/Dorsal glide

Tip

To remember this, I like to think about the fact that all of the finger joints are concave on convex when moving in open kinetic chain. Thus, it helps me to remember that the thumb’s saddle joint is concave-on-convex when moving into flexion and extension. Since it is a saddle joint, I know that the other plane (abduction/adduction) must be convex-on-concave,