Education

Shoulder Injuries

Tennis serve causing you grief?

Unable to lie on one side due you your shoulder?

Struggling to lift up your kids due to shoulder pain?

 

We realise that shoulder pain keeps you from doing what you enjoy. As Physiotherapists we’ve seen the rotator cuff injuries and frozen shoulders, dealt with the post op rehabs and managed the sporting shoulder. At Fix Physio in the CBD, we’ll work with you to assess your injury and then get to work on fixing you up, so you can return to what you love.

The science part….

The shoulder is an extremely sophisticated joint and is made up of a ball and a socket. It is the most mobile joint of the body and as such it is the least stable- this is why it is the most common joint that we see suffering from dislocation injury.

The shoulder complex is made up of 3 bony structures:i. The Humerus- the long bone of your upper arm. This forms the ball of the shoulder joint.ii. The scapula or shoulder blade- this forms the cup of the shoulder joint.iii. The Clavicle or the collar bone- this joins to the acromion of the scapula and together they form the Acromioclavicular joint (AC joint). The ball of the upper humerus and the cup of the scapula (glenoid) form the Gleno humeral joint or shoulder joint.Flexibility vs stability

Compared to the more stable hip, the socket of the shoulder joint is much smaller and far more shallow in order to allow the shoulder joint to go through the extreme ranges of movement that is required of it. Due to this smaller and more shallow cup, the body has several other structures which make the shoulder joint more stable:

i. The Glenoid labrum- this is a cartilage structure which forms a concave circular rim around the edge of the glenoid (socket) to make it deeper and therefore more stable.[Diagram of the glenoid labrum]

ii. The Rotator cuff- this is a group of 4 muscles that travel from the scapula to the humerus to pull the ball of the shoulder joint into its cup. Due to the often excessive demands placed on these Rotator cuff muscles, they can often be the source of shoulder pain as their capacity (or strength) does not match the loads being placed on them and they can breakdown.

[Diagram of Rotator cuff muscles]Infraspinatus Teres Minor Diagram Subscapularis Diagram Supraspinatus Diagram

iii. Long Head of Biceps- The bicep muscle has 2 heads (hence the name “bi”ceps)- the Long head and the the short head. The Long head of biceps is situated at the front of the shoulder joint and so helps prevent forward movement of the ball of the shoulder in its cup.

 iv. Ligaments- There are numerous ligament structures surround the shoulder joint to provide stability to the joint in all directions.[Diagram of the shoulder ligaments]

v. Capsule- The capsule is a fibrous structure which surrounds the joint like a sock. It’s main purpose is to contain the synovial fluid (a fluid naturally within the joint which replenishes the cartilage and assists mobility) but it does have a small role in assisting the stability of the joint.

 Typical muscle weaknesses of the shoulder There are 2 stabilising muscles that commonly become weak with the majority of shoulder injuries- namely:i. Lower Trapeziusii. Serratus Anteriori. Lower TrapeziusThis muscle attaches from the lower thoracic (mid back) spine, its fibres travel upwards and outwards and finish on the inferior angle of the scapula[Diagram of the lower trapezius]Weakness of this muscle causes as “winging” of the shoulder blade (as seen in video below) which alters the whole mechanics of the shoulder complex and can ultimately results in shoulder injury. At Fix Physio we work to strengthen these lower trapezius muscles and therefore restore normal shoulder mechanics.ii. Serratus Anterior This muscle attaches from underneath the shoulder blade from rib 3-8 and attaches to inside border of the scapula. It is often referred to as the “punching muscle”.[Diagram of the Serratus Anterior]Weakness of this muscle causes a “shark fin” effect of the shoulder blade on the rib cage which again alters the whole mechanics of the shoulder complex and often results in shoulder injury.At Fix physio we work to strengthen these Serratus Anterior muscles and therefore restore normal shoulder mechanics..