Do Vertical Mice Reduce Carpal Tunnel Pressure? A Review of Clinical Evidence (2025)

Do Vertical Mice Reduce Carpal Tunnel Pressure? A Review of Clinical Evidence (2025)

Dr. Sig

 

 
Screenshot of the 2015 Applied Ergonomics research paper title by Schmid et al.: 'A vertical mouse and ergonomic mouse pads alter wrist position but do not reduce carpal tunnel pressure in patients with carpal tunnel syndrome.'
Source: Schmid AB, et al. Applied Ergonomics (2015)

Key Research Findings

  • Clinical Efficacy: Current peer-reviewed literature indicates that vertical mice do not significantly reduce intracarpal canal pressure compared to standard mice in patients with Carpal Tunnel Syndrome.
  • The Trade-off: While vertical mice successfully reduce ulnar deviation (sideways bending), they often induce compensatory wrist extension (bending back), which neutralizes the benefits.
  • Activity vs. Posture: The dynamic activity of using the mouse (active movement) elevates nerve pressure significantly more than the static posture of the hand.

The Clinical Reality: Do Vertical Mice Reduce Carpal Tunnel Pressure?

The vertical mouse is frequently marketed as a therapeutic intervention for Carpal Tunnel Syndrome (CTS). The prevailing marketing narrative suggests that neutralizing forearm pronation (rotating the hand to a "handshake" position) will inherently reduce Carpal tunnel pressure (CTP)—Carpal tunnel pressure has been proposed as a causative factor in carpal tunnel syndrome (Rempel 1995).

However, evidence-based ergonomic practice requires that we distinguish between theoretical benefits and measured clinical outcomes. This report reviews two seminal studies—Schmid et al. (2015) and Keir et al. (1999)—to evaluate these claims rigorously.

1. Evidence on Ergonomic Devices for CTS Patients

Source: Schmid AB, et al. "A vertical mouse and ergonomic mouse pads alter wrist position but do not reduce carpal tunnel pressure in patients with carpal tunnel syndrome." Applied Ergonomics. 2015.

This study is particularly significant because it examined patients who had already been diagnosed with Carpal Tunnel Syndrome, rather than healthy volunteers.

The Findings on Pressure

“In fact, the pressure with the vertical mouse and gliding palm support was marginally higher compared to a standard mouse.”
“Importantly, none of the evaluated ergonomic devices that are commonly recommended for CTS resulted in a reduction in pressure. Thus, based on the findings of this study, wrist pads and the vertical mouse cannot be recommended for patients with CTS over a standard mouse if reduction of carpal tunnel pressure is the main criterion.”
Plain Language Summary

If the primary medical goal is to lower the pressure inside the carpal tunnel to relieve the nerve, this study found that vertical mice failed to achieve this. In some cases, the pressure on the nerve was actually slightly higher when using a vertical mouse than when using a standard, inexpensive mouse. Therefore, clinical data does not support the claim that vertical mice are inherently "safer" for the median nerve.

The Mechanism: The "Extension" Trade-Off

“The potential benefit of a neutral forearm position and less ulnar deviation while using the vertical mouse may have been neutralised by a more extended wrist position, which was prominent in this condition.”
“Other authors have also reported a reduced ulnar deviation but increased wrist extension with the vertical mouse compared to a standard mouse (36).”
Plain Language Summary

Ergonomics is often a trade-off. While the vertical mouse successfully corrected one issue—ulnar deviation (bending the wrist sideways)—it inadvertently introduced a new problem: wrist extension (bending the wrist backward). Because bending the wrist backward also increases pressure on the carpal tunnel, this new strain effectively cancelled out the benefits of the "neutral" handshake position.

2. Evidence on Posture vs. Activity

Source: Keir PJ, Bach JM, Rempel D. "Effects of computer mouse design and task on carpal tunnel pressure." Ergonomics. 1999.

This foundational study sought to determine if the shape of the mouse or the rotation of the arm was the primary driver of nerve pressure.

The Impact of Mouse Shape

“Our results indicate that although the shape of the three mice tested altered radioulnar deviation, there was no differential effect on carpal tunnel pressure. Pressure responds very little to small changes in radioulnar deviation angle near the neutral wrist posture.”
Plain Language Summary

The physical geometry of the mouse had very little impact on the pressure inside the nerve tunnel. Even though different mouse shapes changed the angle of the wrist bones slightly, the pressure on the nerve remained statistically unchanged. This suggests that minor ergonomic adjustments to device shape do not automatically result in medical benefits.

The Impact of Forearm Rotation (Pronation)

“Mousing, in general, promotes a fully pronated forearm. Forearm rotation has been shown to affect carpal tunnel pressure... However, from the data in both papers, it appears that there is relatively little effect of pronation in the range tested.”
“The data from Rempel et al. (1998) indicate minimal effect of forearm posture, from neutral to full pronation, on carpal tunnel pressure. Werner et al. (1997)... also found minimal differences between ‘pronated’ and ‘semi-pronated’ forearm positions.”
Plain Language Summary

This finding challenges the core marketing claim of vertical mice. The data indicates that rotating the arm from "palm down" (pronated) to "handshake" (neutral) causes minimal difference in actual carpal tunnel pressure. The body appears to tolerate forearm rotation relatively well, implying that the "twisted arm" is not the primary cause of intracarpal pressure buildup.

The Impact of Task Activity

“There was, however, a significant increase in carpal tunnel pressure when using the mouse as opposed to resting the hand on the mouse (i.e. static posture).”
Plain Language Summary

The significant risk factor identified was not the position of the hand, but the activity of the hand. Simply resting the hand on a mouse generates low pressure. However, the moment the user begins to actively use the device (moving the cursor, clicking buttons), the pressure spikes significantly. This suggests that the effort of use—the muscle tension required to perform the task—is a more critical variable than the angle of the wrist.

Conclusion

Based on the rigorous data from these two studies, the vertical mouse presents a biomechanical paradox. While it visually aligns the forearm in a "neutral" posture, this realignment does not translate into a statistically significant reduction of intracarpal canal pressure.

The failure to reduce pressure appears to stem from compensatory wrist extension (Schmid et al., 2015) and the fact that task-related exertion overrides postural benefits (Keir et al., 1999). Consequently, the vertical mouse cannot be clinically prioritized over standard mice solely for the reduction of carpal tunnel pressure in CTS patients.

References

  1. Schmid AB, Kubler PA, Johnston V, Coppieters MW. (2015). "A vertical mouse and ergonomic mouse pads alter wrist position but do not reduce carpal tunnel pressure in patients with carpal tunnel syndrome." Applied Ergonomics, 47, 151-156. Source
  2. Keir PJ, Bach JM, Rempel D. (1999). "Effects of computer mouse design and task on carpal tunnel pressure." Ergonomics, 42(10), 1350-1360. Source

 

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Dr. Sig

Dr. Sig , Medical Imaging Doctor

Founder of X-Bows and a medical imaging doctor who designed the keyboard based on biomechanical and anatomical evidence to solve the public health crisis of typing-related pain.

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