22. Increased muscle tension

ADHD is often accompanied by increased muscle tension. This is not an expression of hyperactivity or a fundamental motor dysfunction. There are high-performance athletes with ADHD; no fundamental motor dysfunction can be attributed to them. Nevertheless, increased muscle tension can also be observed in them.

According to Stray, the motor disinhibition and increased muscle tone in ADHD is directly associated with dysregulation of the dopamine and noradrenaline systems.¹
This is matched by the fact that in ADHD, increased muscle tone is directly reduced by methylphenidate.²

The reticular system is involved in³

• Arousal regulation
• Maintenance of muscle tone.

The formatio reticularis can thereby ³

• activate several muscles at the same time
• Modulate body position adjustments for balance
• for this, affect the stabilizing muscles (the proximal limb muscles and muscles that stabilize the spine).

The reticulospinal system (the set of descending fibers from the formatio reticularis) is important for³

• Regulation of posture control
• Movement regulation
• Reduction of muscle activity in REM sleep

Muscle tension, especially in the shoulder/neck area, is much more common in ADHD.
So far, we have not been able to find a plausible neurophysiological explanation for this.
An orthopedist explained to us that during sleep, the muscles farther away from the trunk (spine) relax first, while those on the spine relax last. These require undisturbed deep sleep in order to relax.
Accordingly, muscle tension could also be a consequence of impaired sleep in ADHD.