Introduction to Joint Mobility & Stability (Part 1):
Aligning the Basics
- We begin below with the technical details, by reviewing the basics of joint anatomy and unpacking the concepts of “mobility” and “stability.”
- In Part 2, we’ll look at different types of stability and the vital role that stiffness plays in maintaining injury-free movements.
- The third article expands on the concept of stability into other parts of the body, including one of the most talked-about areas of musculoskeletal control, the abdominal core (which is different from a six-pack!)
- Finally, Part 4reveals how you can maintain stability while going about your daily activities and highlights how things can go wrong when your body’s stabilizing mechanisms fail.
Anatomy of a Joint… Simplified**Admittedly, it’s not necessarily all that easy to “simplify” one of the most frequently used joints in the human body. But for simplicity’s sake, let’s start with the basic mechanics of a single joint and its moving parts. A basic model of a joint has two bones in contact with each other; the contacting ends are lined with smooth cartilage at the ends where the bones meet or “articulate” (see Figure 1A).
Physically restrain end-ranges of movement, while at the same time, guiding the available motion in a way that’s mechanically safe for our joints.
- Aren’t actively controlled
- Are non-contractile
When contracting, they pull on our bones—thereby creating movement—or compress one bone into the other—thereby creating active stiffness that’s essential for safe movement.
- Actively controlled
- Contract with movement