AC Joint pain - The "Other" Shoulder Pain

Anatomy

The Acromioclavicular (AC) joint is located at the lateral tip of the shoulder. The joint is formed by two bones, the clavicle (collarbone) and the acromion (a portion of the scapula/shoulder blade). In between the joint sits a fibrocartilage meniscal disc and the bones are connected by a number of ligaments, muscles and a joint capsule.

Role

The AC joint acts as a pivot point in the shoulder allowing the shoulder blade to rotate as the arm is lifted upwards. If it is dysfunctional it affects the control of your shoulder.

About

The AC joint is very commonly injured in contact sports that involve tackling like rugby or AFL. This is classified as a traumatic injury in which the ligaments can be torn and the capsule disrupted which results in the bone separating. However, you can also have AC joint pain from overloading the joint or degeneration of the fibrocartilage meniscus. It can also develop into a condition called osteolysis which is quite common in gym goers.

Differentiation from “bursitis” or impingement (common shoulder pain)

Shoulder bursitis/impingement is a very common condition in which the bursa and tendons in the shoulder get inflamed or overloaded. Often a cortisone injection is prescribed which can reduce the pain if the bursa is the main issue. However, if it is not the correct diagnosis then ongoing pain and disability can perpetuate. It is very important to get your shoulder assessed by a physiotherapist to differentiate between the two conditions so the right treatment plan can be selected. Please note that Impingement CAN occur as a result of AC joint pain or injury but is not the primary diagnosis.

Common presentation

·         Pain at the top or tip of the shoulder

·         Difficulty lying on the shoulder

·         Difficulty bringing the arm across the body

·         Pain with lifting an object above your head

·         Pain with gym activities like bench press

General advice

·         Try icing the area especially when it is painful

·         Rubbing voltaren gel on the area can help reduce pain, the joint is superficial enough for the gel to have some effect

·         Applying taping to pull the shoulder upwards can take the pressure off the joint and relieve discomfort

·         A structured rehab program is helpful in making the muscles around the joint stronger so there is less load on the area

·         A cortisone injection can be helpful if conservative treatment isn’t effective, as long as they inject the right spot

·         Most importantly, visit your highly trained physiotherapist for a thorough assessment and in-depth treatment plan

THE IMPORTANCE OF MUSCULOSKELETAL SCREENING

Finals time for most winter sports is fast approaching and from a physiotherapy perspective this is the time of year that we see a spike in sporting injuries. A lot of these injuries tend to be to parts of the body that have some sort of deficit, be it strength, length or control. It is quite hard to be able to identify these areas yourself and even physiotherapists would find it hard to accurate identify these deficits purely through observation.

This is why screening is so widely utilised for athletes from amateur to elite. Screening usually involves a battery of tests that give objective measurements that are then compared to the normal values for an athlete in a specific sport. Screening can also involve questionnaires that focus on general health and previous injury history.

An article by Sanders, Blackburn and Boucher (2013), looked at the use of pre-participation physicals (PPE) for athletic participation. They found PPE’s to be useful, comprehensive and cost effective. They explained that PPE’s can be modified to meet the major objectives of identification of athletes at risk.

An article by Maffey and Emery (2006) looked at the ability of pre-participation examinations to contribute to identifying risk factors for injury. They found limited evidence for examinations in terms of the ability to reduce injury rates among athletes. However, they were effective in the identification of previous injury (such as ankle sprains) and providing appropriate prevention strategies (such as balance training). From this it has been shown to reduce the risk of recurrent injury. It may also be useful in identifying known risk factors which can be addressed by specific injury prevention interventions.

An example of a screening measure that is typically used in screening protocols includes a knee to wall test (KTW). This test is used for ankle dorsiflexion as well as soleus muscle length (one of your calf muscles). The test is performed using a ruler which is placed perpendicular to a wall with no skirting board. The athlete puts their foot flat on the ground next to the ruler and as far from the wall as possible as long as their knee is touching the wall. Distance from the wall to the end of the big toe is noted by looking at the ruler. An example of a normal distance for netball players is greater than 15cm on each side.

Here at East Vic Park Physiotherapy we have developed a number of specific musculoskeletal screens for a variety of sports including netball, running, swimming and throwing sports. They comprehensively identify the key risk factors that are seen in injuries sustained in each sport. If you are interested in preventing injury for the upcoming sports season, then contact the clinic on 9361 3777 and book your screening appointment today!