Studying the skeletal system is often ignored in favour of learning the muscles. However, without knowledge of the skeletal system it will be a struggle to learn the joints and the origins and insertions of the muscles. Any standard text book will give the student sufficient knowledge of bone makeup and function. My purpose here is to give students an easier way of remembering the human skeleton and the bone groups.
The body and all of its structures are named by location, size, shape or action and usually done so in Greek or Latin. Through even my poor grasp of ancient language, I have retained the information infinitely better than trying to memorise everything, so maybe it will help you too (see below)!
Watch out for the same area having two different names, as one has a Latin root and the other is Greek – confusing I know!
A full list would be impracticably enormous, so I have focused on the ones you will see on anatomy charts and will most likely be tested on.
|Acromioclavicular joint||AC Joint, Acromion and clavicle|
|Acromion process||Acros=highest, ōmos=shoulder, process=outgrowth|
|Clavicle||Small key, suggesting it locks the arm to the body|
|Coccyx||Cuckoo, apparently it is the same shape as the beak|
|Coracoid process||Corvas=raven, oid=resembles, process=outgrowth.|
|Craniomandibular joint||CMJ cranium=skull, mandibular=jaw|
|Cruciate ligament||Crux=cross, but could also refer to crus=leg, ligament/ligure=to bind|
|Femur||Thigh, anatomically the thigh is the top half and the leg starts from below the knee|
|Forearm||Fore=before/in front of|
|Frontal bone||Come on…|
|Glenohumeral joint (GH Joint)||Glen=shallow, umeral=arm.|
|Glenoid fossa||Glen=shallow, oid=resembles, fossa=ditch|
|Humerus||Umeral=arm. Because of the sensation of hitting this area we then get humerus or funny bone|
|Kyphotic||Kyphos=bent forward/ hunchback|
|Lateral collateral ligament||Lateral=side, col=together with, lateral=side or parallel, ligament=to bind|
|Lateral condyle||Lateral=side, condyle=knuckle/knob|
|Mastoid||Mastos=breast (Greek), oid=resembles. I can’t see it myself..|
|Medial collateral ligament||Medial=middle, col=together with, lateral=side/parellel, ligament=to bind|
|Medial condyle||Medial=middle, condyle=knuckle/knob|
|Medial malleolus||Medial=middle, malleus=mallet/ hammer|
|Meniscus||Mene=moon/ meniskos=cresent (Greek)|
|Metatarsals (beyond the ankle)||Meta=beyond, tarsals=ankle|
|Occipital||Occipit=back of the head|
|Patella||Pan / dish, your knee cap|
|Phalanges||Phalanx=tightly formed military position|
|Popliteal fossa||Poplit=ham, fossa=ditch|
|Pubic symphysis||Pubis=bone of the groin ,symphysis=growing together|
|Sacrum||Sacred (Os sacrum= the holy bone)|
|Tarsal||Flat of the foot|
|Zygomatic||Zygoma=yoke/pair/arch, so bony arch of the cheek|
The bones of the Wrist
|1:Scaphoid||Scaph=bowl/boat (Greek), oid=resembles|
|2:Lunate||Luna=moon/ lunate=cresent moon (Latin)|
|5:Trapezium||Trapeza=table, has a deeper grove than the next bone which accommodates the thumb|
|7:Capitate||Having a head describing the rounded portion of this large central bone|
|These can be remembered by the first letter of each bone using the mnemonic:
Some Lovers Try Positions That They Cannot Handle
Prone right hand
Proximal row 1-4
Distal row 5-8
Ankle and foot bones
|Calcaneus||Chalk, maybe because this bone resembles chalk|
|Medial Cuneiform||Medial=middle, cunei=wedge, form=shape|
|Inferior Cuneiform||Inferior=below, cunei=wedge, form=shape|
|Lateral cuneiform||Lateral=side, cunei=wedge, form=shape|
|The order can be remembered on the right foot, superior to inferior, medial to lateral using the first letter of each bone with the mnemonic Tiger Cubs Need MILC|
The axial skeleton
This grouping consists of around 80 bones. The important ones to remember are the skull (and its various fixed bones), the hyoid, clavicle, rib cage, sternum, vertebral column, including the sacrococcygeal region (but not the rest of the pelvis).
The vertebral/ spinal column
We have 33 vertebrae (excluding the odd outlier), including 24 moveable or presacral vertebrae. In turn these consist of the seven cervical, twelve thoracic and five lumbar vertebrae (think breakfast at 7, lunch at 12 and dinner at 5).
We then also have the sacrococcygeal region which has five fused sacral vertebrae and for fused coccyx bones (or tailbone).
Confusingly some courses only count the 24 moveable vertebrae as the spine and the rest is called the ‘pelvis’. Some only partially acknowledge the sacroccygeal region and say the sacrum counts as one vertebrae and the coccyx as another giving us 26 vertebrae.
So the answer in an exam to ‘how many vertebrae are there?’ Will range from 24,26 or 33 depending what the course chooses to teach. Be warned, I have seen some course material differ from the expected exam answers!
Romancing the bone
There is a difference between movement and motion-movement is the wanted action and motion is the involuntary result of it. This goes a little beyond what is taught during the average fitness qualification, but is very much worth being aware (read on!).
Usually we are taught about the various joints: plane, hinge, pivot, saddle, condyloid and ball and socket. We also learn about planes of movement that refer back to our basic anatomical position (mentioned in the previous post here) and the different ways we can move: flexion, extension, rotation and so on. There are plenty of resources to see examples of all these, but that is where the usual lessons stop and this section begins.
These movements of the body are also known as ‘osteokinetic movements’-they describe the movement we see. What is less commonly explained is joint motion or arthokinematic motion. It is less visible if at all but can sometimes be felt.
Regardless of joint type, one adjoining surface will concave and the other convex. When one surface moves, it will create spin (which we can largely ignore), roll and glide. Whichever of the surfaces is moving does not alter the osteokinetic movement, but will change the arthokinematic motion i.e. which direction the roll or glide occurs. This is called the convex-concave rule.
This rule means a concave surface moves in the same direction as the motion whilst a convex surface will move in the opposite direction. In either case the glide will occur in the opposite direction. Why is this important?
Let us consider the knee’s tibiofemoral joint. Here the femur is the convex surface and the adjoining tibia surface is concave. During a leg extension, the femur is fixed so the convex surface will roll and glide in the same direction, meaning the points of contact will be constantly changing, like a wheel-spin. Now during a squat, we still get extension of the knee, but here tibia is the fixed joint so the convex surface of the femur will roll and glide in opposite directions as though it was a paint-roller going over a wall. Much less friction, even though the joint movement is the same.
For anyone doing manipulative therapy this stuff is essential, but for trainers you may have a client who finds one exercise causes discomfort. By applying your understanding of the preceding paragraphs, rather than skipping the body part or randomly trying different exercises, you can make more educated guesses on legitimate alternatives.
Joint end ranges
A joint can hit two sorts of end ranges: one in a close packed position and the other extreme is in a loose or open packed position.
The closed packed position is where all the bones in a joint fit precisely together and where there is maximal contact between the articulating surfaces. The ligaments are taut and twisted and no further movement is possible. This position is the final limiting position of the joint. Anything beyond this point leaves the joint liable to traumatic damage.
In an open packed position there is the least friction between articulating surfaces which allows more movement (including rolling, spinning and gliding). The maximum open packed position is the position in which the capsule and the ligaments are most lax and separation of joint surfaces is greatest and the chance of injury at its highest.
This is good to know if you are trying to take a client into a stretch or you are trying to perform a joint manipulation. It gives a way to ‘lock off’ sympathetic body parts when trying to zero in on one joint or muscle group. Joint angles and body positions influence the range (and quality) of movement. There will be a pathological end range to a joint, i.e. its true anatomical limit. But, from certain positions an artificial end range can occur-an active end range but still within the joints limits. The distance between the two is a buffer between allowable movement and injury where joint manipulations are meant to occur, which is sometimes called the ‘paraphysiological’ space.
I hope you have found this useful. In the next section we are going to look at the muscular system, particularly how to remember the individual muscles and groups of muscles.