The joint-by-joint concept
The “Joint by Joint” concept is a simple and elegant way of looking at human movement, it can help to explain the causes of non-contact injuries, and grade the appropriateness of our exercise choices. It was popularised by strength coach Michael Boyle and physiotherapist Gray Cook, and ties in perfectly with the FMS.
First, a couple of definitions to clarify, for the purposes of what this approach describes
Mobility – What a joint system is capable of performing without outside influence. To use an analogy of a swinging door, think of how much the hinges can move.
Stability/Motor Control – The ability of a joint system to, volitionally or reflexively, maintain a desired position in the presence of forces acting upon it. Or how well can the door, on freely moving hinges, be controlled, and not swing wildly or slam shut.
The joint by joint concept proposes that efficient human movement is achieved through a series of stable segments moving on mobile joints. As follows:
Big toe – mobility
Mid foot – stability
Ankle – mobility
Knee – stability
Hip – mobility
Lumbar spine (lower back) – stability
Thoracic spine (upper back) – mobility
Lower cervical spine (neck) – stability
Upper cervical spine – mobility
Scapula (shoulder blades) – stability
Glenohumeral (shoulder) – mobility
Elbow – stability
Wrist – mobility
And so on, including every little joint in the body.
Now this is not to say that each joint segment is akin to a light switch, being wholly switched to either mobility or stability, rather it is positioned somewhere along a linear spectrum, needing both qualities to varying degrees, as the moment requires, and the structure allows.
As we age, our environment, habits, and previous injuries, alter our movement and positioning, such as sitting for prolonged periods. We begin to develop inappropriate and sometimes aberrant compensatory movement patterns, and some change to the natural order of the system develops. Joints needing a higher degree of mobility tend to give this up and become stiff, joint needing more reflexive stability tend to get sloppy.
As to which causes which, an initial loss of mobility or stability in a given segment, is not always clear, but really doesn’t matter, as the entire system is dependant on the parts around it. You need joint independence before you can get joint interdependence, and then complex movement.
Let’s use the ankle in an over-simplified example: inappropriate footwear, gradually reduced movement over time, poor sensory input, repetitive and prolonged positions, and the ankle needing high levels of mobility can start to get stiff, and the knee could begin to compensate and move to a greater degree than it is structurally suited, this could result in knee pain.
The hip, favoured toward the mobility end of the spectrum, called upon to use a range of motion it hasn’t seen for years, and the lower back gets stretched out to accommodate, moves a little further than it should, ending up with back pain.
The thoracic spine needs mobility, sitting in a desk, in a car, looking down at your phone all day will stiffen that curve up really quick, to get into an overhead position, for instance, may require the scaplula to move beyond their normal range of control, or the lumbar spine may arch more than form allows: Shoulder pain. Back pain.
The point here being that the human body is designed to move in a certain fashion, with the function of joints dictated by their form, and adjusted within that range as needed. Break these patterns and this can lead to dysfunction, decrease in performance potential, and injury.
Choose exercise and activities that honour the joint by joint concept and you will increase your joint health, longevity, performance and outcome potential, and reduce the chances of soft-tissue injury.
Mobilise your ankles, hips, thoracic spine, and shoulders. Train for reflexive stability in your lumbar and scapula regions. Your joints will thank you.