With the current spaciousness in my schedule, I decided to do something I’ve been wanting to do for years: learn more about the carpal bones! For years, knowing the tarsals has helped my work be more precise and effective. I’m excited to see where this takes me with clients.
How I learned:
Richard has been an obliging client, who conveniently (for me!) has a minor wrist injury from more gardening than usual. Slow, methodical palpation while looking at our plastic forearm model was super helpful. Usually, with clients I feel obliged to stay focused on their treatment. Knowing I could take my time palpating and noodling around was such a treat. I had time to allow my fingers and my mental anatomy atlas meet each other. Then there’s the coloring, mnemonics and some youtube viewing — see links below. Here are some details and insights from my study.
Most mammals have the same number of bones in their appendages, and the upper and lower appendages mirror each other. Distal to the ball-and-socket joint at the girdle, each appendage has:
• one long bone (humerus/femur), followed by a
• two slender bones (radius-ulna/tibia-fibula), followed by
• a cluster of small, rounded bones (carpals/tarsals), then
• five shorter ‘long’ bones (metacarpals/metatarsals – “meta” means after or beyond), and lastly,
• a series of phalanges (fingers/toes).
Like the tarsals, the carpal bones arrange themselves in 2 ways: horizontally across the wrist in two rows, and vertically (roughly) in 2 clusters, relating to either the radius or ulna. In the foot, those separations coordinate with the medial and lateral arches; they relate to the thenar and hypo thenar pads in the hand.
There are 8 carpal bones, here listed in their horizontal row (with the forearm bone or metacarpal noted):
• lunate (ulna); beyond that the triquetrum, pisiform (5th MC), hamate (4th MC)
• scaphoid (radius); beyond that the capitate (3rd MC), trapezoid (2nd MC), trapezium (1st MC)
The joints include elliptical joints between the forearm and first row of carpals (wrist flexion/extension), and sliding joints (among each each and with the metacarpals). Our one and only, world famous saddle joint of the thumb — between the trapezium and the 1st metacarpal — is the one that makes human hand capacity so unique!
Starting from the ulnar side, when I palpate my own wrist on the anterior side I notice:
• A little gap between the end of the ulna and the lunate holds a disc to cushion strong impacts.
• Just distal to that gap, is the prominent pisiform, at the ‘heel’ of the hand.
• Rounding around the pisiform toward the midline of the wrist, you’ll feel another clear edge. That’s the “hook” of the hamate — really that’s its name. Ligaments that create the carpal tunnel attach to this hook.
• The capitate and trapezoid are easiest to feel posteriorly, same with scaphoid.
• Once you’re on the radial side, the trapezium has a projection, but it’s called a ‘tubercle’ — a distinct edge when you roll toward midline.
• The scaphoid also has a small tubercle. The two tubercles are the attachment sites for the other end of the ligaments that form the carpal tunnel.
Palpation = Treatment
Gliding these bones between themselves feels really good!
With the client’s palm facing me, I take my thumb on one side, and index and middle fingers on the back of the wrist. I locate a single carpal bone — for example, one on the hamate, one on the capitate. Using an anatomy image is helpful with this level of detail.
Then glide them gently in opposite directions. When you feel a motion barrier, gently meet it and then sustain your engagement. Give the joint time to respond and release. Remember that the overall range of most of these joints is quite small. Don’t look for large movements, just little bits of sliding past each other.
Anchoring the information — whatever helps!
Youtube links that might be fun:
• Ninja Nerd Science: short discussion of hand anatomy; this guy’s great!
• Armando Hasudungan: cartoon drawn discussion of wrist and hand
• Physiotherapy is Rehabulous: online lecture with charts and diagrams
Mnemonics — with the capital letter of each word/bone matching.
• Some Lovers Try Positions That They Can’t Handle
Scaphoid — Lunate — Triquetrum — Pisiform — Trapezium — Trapezoid — Capitate — Hamate
• Never Lower Tilly’s Pants, Grandmother Might Come Home
Navicular (old name for scaphoid) — Lunate — Triquetrum — Pisiform, — Greater multiform (old name trapezium) — Multiform (old name trapezoid) — Capitate — Hamate
From the Anatomy Coloring Book and Netter’s Anatomy Coloring Book. (If you’d like some pdf’s of these pages, let me know.)