Proprioception Deficits in Hypermobility: Validated assessment tools and clinical implications for PTs.

Joint hypermobility is fundamentally a challenge of joint stability, but the underlying issue often stems not just from lax ligaments, but from compromised sensory feedback. For patients with Hypermobility Spectrum Disorder (HSD) or hypermobile Ehlers-Danlos Syndrome (hEDS), proprioception—the awareness of joint position and movement—is frequently impaired. This sensory deficit is a major contributor to functional clumsiness, recurrent sprains, chronic pain, and poor motor control.

Understanding and addressing this deficit is arguably the single most important element of the physical therapy management plan.

The Mechanism: Why Proprioception Fails

In healthy joints, proprioception is governed by mechanoreceptors embedded within the ligaments, joint capsules, and muscles. These receptors constantly feed information about joint angle and rate of movement to the central nervous system (CNS).

In hypermobility, the connective tissue that houses these mechanoreceptors (primarily collagen) is structurally compromised. This means:

1. Reduced Ligament Tension: The laxity reduces the mechanical tension on the receptors, dulling their signal, especially at the end range of motion.
2. Delayed Muscle Response: The CNS receives faulty or delayed information, leading to inadequate or slowed muscle activation—the exact moment a subluxation or injury occurs.
3. Reliance on Vision: Hypermobile individuals often develop a compensatory reliance on visual feedback to orient their limbs, which fails during dynamic, unexpected, or low-light activities.

Validated Proprioception Assessment Tools

Traditional goniometric measurements only capture passive range of motion. To truly assess the functional deficit, physical therapists must use tools that quantify Joint Position Sense (JPS), the most common metric for proprioceptive acuity.

1. Joint Position Sense (JPS) Reproduction Test

This is the gold standard for clinical assessment. It measures the patient’s ability to actively or passively reproduce a pre-determined joint angle.

• Method: The patient is positioned with eyes closed or occluded. The therapist passively moves a joint (e.g., the knee or shoulder) to a target angle. The patient is asked to memorize the position. The limb is returned to neutral, and the patient is then instructed to actively or passively reproduce the target angle.
• Measurement: The error is measured in degrees using a goniometer or inclinometer. A high degree of error indicates a proprioceptive deficit.

2. Functional Balance and Stability Tests

While these tests measure function, they are excellent indirect measures of the proprioceptive system’s ability to maintain equilibrium under stress.

• Star Excursion Balance Test (SEBT): Highly reliable for lower extremity dynamic stability. It requires the patient to maintain single-leg stance while reaching with the contralateral limb, challenging proprioceptive limits.
• Single-Leg Stance (SLS) on Unstable Surfaces: Testing SLS on foam, a balance board, or a wobble cushion (with eyes open and closed) quickly reveals significant stability deficits. The time and amount of sway are quantifiable outcomes.
• Timed Up and Go (TUG): While broader, poor proprioception contributes directly to slower and more cautious TUG times.

Clinical Implications for PT Treatment

The presence of a proprioceptive deficit mandates a distinct hierarchy in the rehabilitation program, shifting the focus away from simply increasing muscle bulk.

1. Prioritize Sensory Input Over Strength

Initial therapy must focus on re-educating the nervous system. This means low-load exercises performed with maximal sensory focus, often involving closed-chain and weight-bearing activities.

• Static Postural Holds: Begin with basic static poses (e.g., quiet standing) on firm ground, focusing purely on minimizing sway.
• Tactile and Auditory Cues: Use verbal cues (e.g., “Feel the pressure on your heel”) or external tools (e.g., tape or pressure biofeedback) to provide enhanced sensory input the mechanoreceptors fail to deliver.

2. Progressing Proprioceptive Training (The Hierarchy)

Training must progress systematically:

• Eyes Open $\rightarrow$ Eyes Closed: Removing visual input forces reliance on proprioception.
• Stable Surface $\rightarrow$ Unstable Surface: Progressing from the floor to foam, balance pads, or mini-trampolines.
• Static $\rightarrow$ Dynamic: Moving from holds to rhythmic stabilization and perturbation exercises (e.g., catching a light ball while standing on one leg).
• Slow Velocity $\rightarrow$ Increased Speed: Incorporating reactive exercises to train the fast motor response necessary for joint protection.

3. Patient Education: The “Safe Range” Concept

Crucially, PTs must educate hypermobile patients on the importance of movement control within their safe, functional range, not their anatomical end range. Proprioceptive training helps them identify this mid-range of stability and control, thereby protecting their vulnerable joints from unnecessary ligamentous strain and reducing the risk of injury.

By critically assessing and meticulously training the proprioceptive system, Joint hypermobility physiotherapist Gold Coast can move beyond temporary symptom management and provide HSD/hEDS patients with the lasting internal stabilization needed for improved function and quality of life.