Blog posts of '2019' 'May'

Shoulder Prevention Part 2: The Shoulder During Manual Wheelchair Propulsion



What happens when an individual propels a manual wheelchair?  What muscles are being activated? Does it change across the lifespan?  We will not cover this entire topic today but let’s begin with what is happening with the shoulder during manual wheelchair propulsion.

The first question we have to ask is WHY?  Why are we even talking about the shoulder during manual wheelchair propulsion?

Because the number of individuals who are full-time manual wheelchair users who will develop shoulder dysfunction and/or pain at some point in their life is staggering.  There is up to a 73% reported incidence of repetitive strain injury among full-time manual wheelchair propellers, with the shoulder being the most commonly reported site.  It is important for everyone, no matter if you are the therapist, carer, family, end-user, or supplier, to come together to provide the optimal equipment and outcome for the end-user to decrease their risk of shoulder dysfunction.

Starting at the very beginning, is understanding propulsion. Propulsion can be broken down into two phases: push phase and recovery phase.  In the photo below you can see the two phases highlighted.  The push phase first begins when the hand contacts the push rim and continues until the hand is released from the push rim.  The recovery phase occurs when the hand is first released until the hand makes first contact again with the push rim.

These are the two phases, but how the individual moves through these two phases can vary. Below is a photo showing a few different types of propulsion techniques. These techniques may be confusing to look at in a photo, so you can also click this link to watch a video discussing the optimal push technique.  This optimal technique, called the semi-circular technique, is discussed in the PVA clinical practice guideline for shoulder preservation referenced at the end. We will discuss propulsion technique further in the next blogs, but for today we will go back to the two phases of propulsion.  During each phase, different muscles will be required or activated.

There are many studies looking into the activation of muscles during propulsion. This research can be challenging due to the inherent number of variables with testing. For today, we will look at a study by Mulroy and colleagues from 2004.  This study looked at individuals with spinal cord injuries and found the following muscles were activated during each phase:

Push Phase:

Anterior Deltoid, Pectoralis Major, Supraspinatus, Infraspinatus, Serratus Anterior, and Biceps

Recovering Phase:

Middle and Posterior Deltoid, Supraspinatus, Subscapularis, Middle Trapezius, and Triceps

Look at the number of muscles involved in propulsion!  What as a therapist, or end-user, are we doing to protect and strengthen the shoulder? We want to be sure that we are addressing the shoulder from the beginning whether this is through stretching, strengthening, positioning, modifications or education. This will vary for each individual based on their pain level, diagnosis, strength of each muscle, etc… It is best to have an individual program designed by a therapist to ensure that the end-user is safe.

Next week, we will continue to discuss the shoulder and manual wheelchair propulsion, propulsion technique, and look at some of the ways our end-users are taking care of their shoulders!


Shoulder Preservation



Part 1: Starting with a Foundation

As a therapist working with individuals with mobility impairments, did you ever think you would have to know so much about one joint? What joint am I talking about? The SHOULDER! I remember sitting in a classroom many years ago now, telling my classmate that I couldn’t wait to get past the orthopaedic semester and get to the neuro semester. I knew that I wanted to go on after my degree to work with individuals with spinal cord injuries, why did I need to sit through this whole semester on orthopaedics? Of course, after my clinical rotation on my neuro complex, I realised the importance of that semester on orthopaedics and the impact that orthopaedics had in every client that I saw. I often hear therapists tell me that they don’t really remember much from their university about the shoulder or that they “aren’t very good with the shoulder”. As a therapist, it can be challenging the amount of information that we are expected to know to a high degree, but understanding the why gives us the foundation to critically think and be able to examine a situation, client, or piece of equipment and formulate our treatment plan or product selection.

Over the next several weeks we are going to be discussing the shoulder.



The shoulder is the joint in the body I feel most passionate about, as many of our clients will be relying on their shoulders to now be their main means of mobility. It is crucial that we understand the shoulder from the inside out, building a foundation, as we want to preserve the strength and integrity of the shoulder for our clients for as long as possible. Today, let’s take a couple minutes to understand why the shoulder has such an impact on our clients.
First, we have to go way back to our anatomy class. We are going to mostly focus on the shoulder joint itself today, but we need to remember that the shoulder complex is comprised of 4 different joints that will all play a role into our client who relays on their shoulders for mobility. These 4 joints include: the glenohumeral joint, referred to as the shoulder joint; the acromioclavicular or AC joint; the scapulothoracic joint; and the sternoclavicular or SC joint. These 4 joints work together to provide the great amount of motion that the shoulder complex has.
We learned that the shoulder joint is a ball and socket joint just like the hip, but unlike the hip, the joint capsule is shallow. Look in the photo below. This shows the difference between the two joints. One of the joints is designed for stability, while the other is designed for mobility, mobility in this case meaning a wide range of motion. Do you know which one the shoulder is? That’s right! Hopefully you said the shoulder is designed for its wide range of motion. The problem is that this comes with a cost. The shoulder because it has such great mobility, is very unstable. There are ways that the shoulder joint gains some stability through the rotator cuff muscles, the ligaments, and the labrum. With these additional supports, do we get the stability in the shoulder we need for our full time manual wheelchair user?


It is important that we consider the demands being placed on the shoulder by an individual with a mobility impairment. We have to consider the mobility impairment and the demand that the impairment places on the shoulders. For example, an individual who is a full-time manual wheelchair propeller versus a full-time power wheelchair user. While the individual who is using the manual wheelchair will have to rely on his/her shoulders for their propulsion, both individuals will have to reach overhead throughout their day. This is a key point that we will come back to in later blog sessions as overhead activity can greatly increase the risk of shoulder pain and dysfunction. We can decrease this risk in a power wheelchair with power seat functions when prescribed, but have we educated the client on the use of these power seat functions for shoulder preservation? Does the client understand the importance of limiting the amount of overhead activity throughout their day? How does this differ from an individual who utilises a manual wheelchair for mobility? Next week, we will begin with the demands of the shoulder for a manual wheelchair user.

Throughout the next several blogs, I hope you will continue to learn about the shoulder, its increased importance for clients with a mobility impairment, and the information that we need to continue to or start to consider when prescribing a manual or power wheelchair.