Wk 5 Magic Bullets
LO Answers
Anatomy: Applied anatomy of the muscles. Upper/lower limb
1. Understand, demonstrate and discuss the muscles related to the shoulder, elbow, wrist joints and the
back.
Just repeating lecture notes here probably not useful. Everyone just needs to plough through these to try
to learn it. Similarly, summarising anatomy as it has been presented is not particularly achievable or
useful. There are a heap of tables etc that summarise site, action, attachments, nerve supply etc in neat
fashion in virtually every textbook.
Tried a functional/clinical approach instead. It may not mean much for exams but might be handy for you
to come back to at some stage. Haven’t listed every muscle or even every group. Just the ones that link
to certain conditions you will see time and time again in clinical practice. This is not meant to be a
complete list of issues or disorders. Sometimes reading about a common condition can help reinforce the
picture of the anatomical structure and its function and help you remember it.
Shoulder Muscles:
Scapular stabilising muscles:
Rhomboids, trapezius, serratus anterior, pec minor (with the exception of pec minor I think this is
what the objectives mean by “back muscles”).
Function:
As a group - to control, anchor the scapula to the chest wall. The shoulder is only
attached to the skeleton via one joint, the sternoclavicular joint. Thus, the shoulder
relies heavily on the muscles securing the scapula (shoulder blade) to the thorax, to give
it a stable base upon which to move. The scapula presents a very shallow “socket” ( the
glenoid ) to the head of humerus. This is, by design, a very mobile joint to allow us to
position our hand in all sorts of weird and wonderful positions.
Clinical Relevance:
The cost for the mobility described above is relative instability of the “passive system”
(bony configuration, ligaments, capsule). Disuse of scapula stabilisers due to direct/
indirect injury or neuromuscular disorders may result in wasting or disturbed patterns of
recruitment of these muscles. Rehabilitation aims to restore strength and bulk to these
muscles, but also to retrain patients in restoring normal control or coordination of these
muscles. Again - this is to provide a solid, well controlled platform from which the
shoulder can “do its thing”.
NB: Strength and control are two different things. One is about developing the
force/power abilities of the muscle – the other is about retraining neuromuscular
patterns of recruitment. Understanding these recruitment patterns is becoming more
and more relevant in terms of understanding why injuries occur and how we can
prevent them happening in a rehabilitative sense.
LO Answers Magic Bullets: Anatomy, Upper and Lower Limb. Marty Roebuck
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Shoulder Stabilisers
Deep Layer:
Rotator Cuff:
Anterior:
Subscapularis
Posterior:
Supraspinatus
Infraspinatus
Teres Minor
Function:
NB: Deep muscles are best positioned to confer stability to joints. They attach close to the centre
of rotation so aren’t designed as prime movers. Along with the ligaments, they are designed to
limit (but allow) glides or translations within the joints and approximate the surfaces throughout
range as the more shallow/superficial prime movers and their assistants produce the actual
movement available at the particular joint. You can divide most of the muscles acting over the
major articulations of the body into deep and shallow muscles to consider their function
similarly. Exceptions are probably the joints in the feet or hands.
The cuff pretty much keeps the humeral head approximated in the centre of the glenoid whilst
the more superficial deltoid, bicep, tricep, coracobrachialis, pec major, lat dorsi, teres major
produce the movements.
Contraction of the discrete parts of the cuff will cause movement ( see “action” of these
muscles). So in part, they are thought of as assisting or helping to initiate movement. Their main
function, however, is to control movement and confer stability to an otherwise relatively
unstable joint.
Clinical Relevance
The cuff, or it’s parts, can be injured acutely in collision incidents, falls, or during dynamic
overhead activities in the home, work or sporting environment. Dislocations or partial
dislocations (subluxations) will often occur in these incidents and underlying damage can occur
to joint structures. At presentation, pain and disability can be quite considerable.
Loss of joint integrity = relative instability = ↑demands on an already damaged cuff, = poor cuff
function = relative instability ↑ = ↑cuff demands
*A vicious cycle
You will probably see relatively more chronic injuries when it comes to the rotator cuff. These
can occur when this vicious cycle is allowed to continue after acute, traumatic incidents.
Alternatively, overuse of the cuff in any setting – but particularly at work or in the sporting
environment with overhead patterns of use. “Overuse” is a relative term. Any significant change
in loading (volume and /or intensity) may induce changes within the cuff “quality”. These
changes usually take the form of a degeneration (rather than inflammation) of the cuff tendons
as they approach the humeral head. We will see this described as tendinopathy. It is now
thought that compressive load upon these tendons is what induces degenerative change –
deformation of collagen and proliferation of ground substance. Think of this as less bricks and
more mortar within the tendon tissue. The tenocytes (cells) within the tissue have a
maintenance/repair function. So the “maintenance man/person” is run off his/her feet trying to
repair damaged tissue – gets more and more ineffective and eventually “leaves the building”
LO Answers Magic Bullets: Anatomy, Upper and Lower Limb. Marty Roebuck
Page 2
People with chronic rotator cuff dysfunction will have less pain compared to the acute setting.
They attend with nagging pain, more intense with elevation primarily. They can limit/avoid pain
by avoiding such positions. So they attend more due to dysfunction.
Bicep
At shoulder (also acts over elbow), assists in flexion and also in adduction when shoulder
elevated ie across body (sometimes called horizontal flexion).
Clinical Relevance:
Degenerative changes to tendon of long head in later life. Picture its course in bicipital groove
where it takes a turn over top of humerus to its attachment on glenoid. Easy to see why it might
be under load ++. Also acute or chronic injuries related to dynamic overhead activities –
particularly throwing sports. Ruptures are common in older age due to such degeneration and
poor tissue nutrient supply. Patients will present with pain (if acute) and a “popeye deformity”
in cases of rupture of this tendon. Rehab includes rehab of proximal musculature – scapula
stabilisers and cuff. Repair is rarely preformed.as the muscle can function well (despite some loss
of power) using the existing anchor point of the short head to the coracoid process.
Elbow / Wrist:
There are rarely problems with the muscles acting over the elbow. Acute ruptures of the distal
attachment of biceps can occur in a traumatic “wrestling” type incident or with a “catching”
event with a suddenly changing or shifting load. Degenerative changes would predispose one to
such an incident.
However tendon attachments at the elbow can be problematic. Medial and lateral elbow pain
often stems from:

tendinopathy of the wrist extensors attaching at or about the lateral epicondyle of the
humerus (lateral epicondylitis – “tennis elbow”).

tendinopathy of the wrist flexors attaching at or about the medial epicondyle of the
humerus (medial epicondylitis – “golfers’ elbow”).
Rehab (in this case and with tendinopathy in general) involves manipulating load (many variables
to consider) upon these structures to firstly allow them to recover/repair (reduce load) and then
to condition them to cope with future loading (increase load in progressive step-wise fashion).
Hand / Fingers:
Muscular function at the wrist and hand is very detailed and complex. Ligament and bony injuries
are quite common in relative terms. In terms of musculo – tendinous function, injuries to the
finger joints are probably the most significant. Damage to these joints can cause specific loss of
function and often deformities due to a resting imbalance of forces across joints – see “mallet
finger”, “boutonniere (button hole) deformity” and “swan neck deformity” as examples.
“Carpal Tunnel Syndrome” can cause widespread muscular dysfunction (thenar muscles - opponens pollicis, abductor pollicis brevis, flexor pollicus brevis, and the lateral lumbricals due
to compression of the median nerve as it passes through a narrow channel in the wrist. The
median nerve shares this channel with several tendons. Changes in bony, tendon, or neural
tissue can cause degenerative and or inflammatory changes within this confined space and thus
compressive neuropathy.
LO Answers Magic Bullets: Anatomy, Upper and Lower Limb. Marty Roebuck
Page 3
2. Understand, demonstrate and discuss the muscles related to the hip, knee and ankle joints.
Hip:
The hip is a relatively stable joint in terms of bony configuration, ligaments and capsular
attachments. Tears and muscle strains about the gluteal area are uncommon. Like the shoulder,
the tendons of the muscular network about the hip are subject to tendinopathy as they approach
their distal attachments after crossing the joint. Treatment for lateral and posterior hip pain has
often focused on bursitis about the greater trochanter, ischeal tuberosity and deep to gluteus
medius. It is now thought this issue of tendinopathy plays a more significant role than previously
thought.
Control of movement at the hip has implications for function and loading not only at the hip joint
itself, but also for the structures proximal (sacroiliac joints, lower spinal joints and tissues) and
distal (knees ,ankles and associated musculature) to the hip. Lectures have emphasised the
stabilising role of the ilio tibial tract and its muscular attachments, gluteus maximus and tensor
fascia lata. Along with other deep (stabilising) muscles in the hip, strength and control work is
often employed when treating people with low back pain for example and also knee pain. If hip
control is poor, repetitive movement patterns in a sporting or occupational sense will cause
excessive load on these distal and proximal structures (not to mention the hip itself).
Knee:
When we consider the forces operating about the knee (tibio-femoral and patello-femoral joints), the
way in which the muscular system controls movement and loading here really is quite extraordinary.
Pain about the patello-femoral joint is one of the more common knee presentations, particularly in
active, growing adolescents. Consider all the muscles crossing the knee and how they contribute to stress
upon the patella-femoral joint. Simplify this to just the medial and lateral forces acting upon the patella
as it tracks up and down upon the femur as the knee flexes and extends during walking, running,
squatting, jumping etc.
The iliotibial tract and hence gluteus maximus and tensor facia lata will tend to hold the patella laterally.
The vastus medialis and vastus lateralis will exert forces upon the patella as their name suggests. The
hamstring and adductor muscles will have an impact on the angulation of the knee relative to the hip and
foot and thus the relative alignment of the patella with respect to the femur.
Acute injuries or chronic conditions about the knee can change the way in which these muscles function
where they might become weak or tight for example. The coordinated actions of the muscles as a group
in terms of timing and speed of contraction will have consequences for patella-femoral function and
stress upon its weight bearing surfaces.
Thinking about the attachments and actions of the muscles, and trying to picture what happens to the
joints that they relate to can be useful. Going beyond that and reading about injuries or conditions that
you, your friends or family experience will help cement the anatomy involved with those injuries in your
memory.
When you get some spare time!
LO Answers Magic Bullets: Anatomy, Upper and Lower Limb. Marty Roebuck
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