Hello anatomy friends this is Dr Alsup and in this video we will be discussing
the joints we need to be able to identify in the forearm, wrist, and hand session.
Starting with the radiocarpal or wrist joint, this joint is formed by the articulation of the distal
end of the radius or the articular surface of the radius and the proximal row at least three of the
four of the carpal bones so those wrist bones all except for this small pisiform which is a
bit more anteriorly placed so it's not directly involved with this articulation. Now obviously
these images are not to scale this radius is a little on the too large size but I did
want to just kind of put them close to one another to get an idea of at least kind of the osteology
and how they articulate. But as with most joints there will certainly be accessory structures
providing stability and support and while we're not having you identify any of these ligaments
individually that you see shaded here we do want you aware that similar to other joints they're
certainly present for the wrist joint as well. So you can see the radiate distal radius right
here those carpal bones would be deep and you can see ligaments kind of protecting this region here.
Moving to the joints of the hand I think these are so much easier to conceptualize when looking
at the bone, as we were just discussing there will of course be ligaments and tendons throughout this
region but for our purposes if you can understand what bones are articulating to form these joints
we'll be very pleased. So starting proximally there are the carpometacarpal joints of which there are
five. And these are formed by the distal row of the carpal bones articulating with the metacarpal
so again these are carpals these are metacarpals and the joint right here between that distal row
and the metacarpals will be your carpometacarpal or CMC joints. 2-5
of the CMC joints are plane joints but this first carpometacarpal joint
has considerably more mobility being a saddle type joint, so it's capable of flexions extension
abduction adduction and circumduction so a lot more mobility associated with that first digit.
Next we reach the metacarpophalangeal or MCP or MP joints which are between the metacarpals and
the proximal phalanges so these would be the MP sometimes you see MCP joints.
These are the joints that kind of form that knuckle region
and these are mostly condyloid joints so capable of those same motions that we just
discussed with the saddle joint just to a slightly smaller degree.
Then we reach the interphalangeal joint so these are the joints between the phalanges in which for
digits 2-5 there are two sets of interphalangeal joints in the first digit there
is only one interphalangeal joint because there is not a middle phalange so this is just referred
to as the interphalangeal joint. But in the other ones the joint between the proximal and the middle
phalanges are called your proximal interphalangeal joints or much more fun to say the PIP joints
and the distal interphalangeal joints are formed between the middle phalanges and the distal
phalanges and these are referred to as the DIP joints or the distal interphalangeal joints.
All interphalangeal joints are hinge joints so they're just capable of flexion in extension.
Excellent I thank you for your time and attention here and I hope you have a great rest of your day