Unsplinted Wrist Flexion During Sleep
Sleeping wrists drift into flexed or extended positions without support.
- 40–60°: Typical flexion (placeholder figure)
- Most: Nights affected (placeholder figure)
- ↓ reduced: Tunnel volume (placeholder figure)
- Late night: Symptom onset (placeholder figure)
Why the wrist flexes unsupported
Placeholder: sleep posture allows unconstrained wrist flexion.
Rising Nocturnal Tunnel Pressure
Flexion angle directly raises pressure inside the carpal tunnel.
- ~20 mmHg: Pressure at 0° (placeholder figure)
- ~110 mmHg: Pressure at 60° (placeholder figure)
- Increases: Nerve compression (placeholder figure)
- ~30 mmHg: Onset threshold (placeholder figure)
Pressure-angle relationship
Placeholder: pressure rises with wrist flexion angle.
Splint Neutral Positioning
A rigid brace mechanically holds the wrist near zero degrees.
- 0–5°: Target angle (placeholder figure)
- High: Brace rigidity (placeholder figure)
- Overnight: Wear window (placeholder figure)
- Nightly: Compliance (placeholder figure)
How the splint restrains motion
Placeholder: splint frame blocks flexion and extension.
Reduced Tunnel Pressure With Splint
Neutral positioning keeps carpal tunnel pressure near baseline.
- ~22 mmHg: Pressure w/ splint (placeholder figure)
- ↓ large: Pressure drop (placeholder figure)
- Preserved: Tunnel volume (placeholder figure)
- Improved: Nerve blood flow (placeholder figure)
Effect of neutral hold on pressure
Placeholder: pressure stays low when angle is constrained.
Decreased Nighttime Paresthesia
Lower sustained pressure reduces numbness and tingling episodes.
- ↓ fewer: Episodes/night (placeholder figure)
- Improved: Sleep quality (placeholder figure)
- 2–6 wks: Weeks to benefit (placeholder figure)
- ~60%: Symptom relief (placeholder figure)
Longer-term symptom trend
Placeholder: paresthesia frequency declines over weeks of use.
Placeholder: consistent nightly splint use compounds relief over time.