Updated: Aug 15, 2021
You’ve probably heard about it, or been told you need to improve either one.
Two very important factors for function of a joint!
It’s sometimes an odd concept to grasp as they are basically opposing ideals that coexist in relation to each other in a reciprocal relationship.
This is where we enter the rumble of Stability V Mobility.
“the greater the mobility, the less stable is the joint; and the greater the stability, reduced is the mobility at that joint.”
A joint as we all know, is the articulation or connecting location of 2 or even 3 bones by muscles and ligaments i.e. Ankles, Elbows, Shoulders, Fingers, Hips…. Yeah, you get it.
This then gets broken down into 3 more ideals (Let’s look at the HIP V. SHOULDER) ↓
→ JOINT CAPSULE: The idea that the more ligaments of the joint or the more joint capsule complex (structure), offer more stability but decrease the ROM (range of movement) of said joint. The Hip has more ligaments and joint capsule complex offer more stability but decreases in ROM. The Shoulder has less ligaments and joint capsule complex offering less stability but has increased ROM.
→ MUSCULATURE: The more strong and massive the musculature that’s crosses a joint, the more increased the amount of stability of that joint.
The Hip has more muscle structure over it than the Shoulder, giving it more stability yet less mobility than the shoulder.
→ BONES: The shape of the bones articulating the joint will determine the amount of stability and mobility it can/will have. This can also depend on the TYPE of joint (e.g. Ball and Socket, Hinge, Pivot etc.)
The Hip and Shoulder are both “ball and socket” joints. The Acetabulum (hip joint capsule) is a deeper socket then that of the Glenoid Fossa (shoulder capsule). This results in the Hip having less mobility to the Shoulder, but more stability.
So, these 3 ideals will determine the amount of stability and mobility of a joint through the correlation that joints with more stability will tend to have a decreased amount of mobility and therefore can have a reduced risk of injury such as sprains and dislocations.
And in opposition, joints that have more mobility will have an increased injury risk factors due to the less stability they have.
After saying all this, these determinants do not have to be the “be all and end all” of a specific joint. That’s why we have strengthening and stability controlling exercises!
To increase the amount of muscle contraction and control we have over specific movements through the ROM of a joint, we can, ourselves, limit the risk of injury through our joints!