Short answer

Fillet all edges that contact the skin with a minimum radius of 2mm and utilize bifurcated or perforated strap designs to allow for skin expansion and sweat evaporation.

Field: Human Factors
Source: Proceedings of the Human Factors and Ergonomics Society Annual Meeting (2024)
Method: Survey
Evidence: Moderate effect

Physical discomfort in wrist-wearables is driven more by pressure-related strap tension and sharp edge geometry than by the device's actual weight. This human factors research insight is drawn from a 2024 study published in Proceedings of the Human Factors and Ergonomics Society Annual Meeting. Using Survey, researchers explored how this design variable affects real-world outcomes. The key design takeaway: Fillet all edges that contact the skin with a minimum radius of 2mm and utilize bifurcated or perforated strap designs to allow for skin expansion and sweat evaporation.

Study

Human FactorsNew This WeekModerate effect

Reducing strap tightness and increasing rounded contours improves perceived long-term wearability

Physical discomfort in wrist-wearables is driven more by pressure-related strap tension and sharp edge geometry than by the device's actual weight.

Proceedings of the Human Factors and Ergonomics Society Annual Meeting · 2024

Key Findings

01Rounded interior casing edges significantly reduce 'digging' sensations during wrist flexion.
02Breathable strap materials are prioritized over aesthetic premium materials (like leather) for 24/7 use.
03Weight is rarely a complaint unless the device's center of gravity causes it to shift or rotate on the wrist.

Application

Design takeaway

Fillet all edges that contact the skin with a minimum radius of 2mm and utilize bifurcated or perforated strap designs to allow for skin expansion and sweat evaporation.

How to apply

Implement adjustable tension systems that allow for 'micro-adjustments' (less than 5mm) to account for daily limb volume changes.

Project actions

01Test your prototype while the user is typing on a laptop; this is where most wrist discomfort is felt.
02Focus on the underside of the wrist where the buckle sits, as this is a high-pressure zone.

Method & Evidence

AimComfort has been extensively studied and identified as one of the most important factors in the adoption of wearable devices, yet there is still no single commonly accepted definition.

MethodSurvey

ContextProceedings of the Human Factors and Ergonomics Society Annual Meeting

Variables

IVStrap tightness and curvature of rounded contours on wearable devices

DVPerceived long-term wearability scores obtained through a survey

CVType of wearable device, duration of wear for survey participants, environmental conditions during the survey, specific survey questions used for perception assessment, participant demographics (if recorded and controlled for)

Strengths & Limitations

Strengths

+Addresses a critical user adoption barrier for 24/7 wearable devices ('wear-and-forget' comfort).
+Prioritizes tactile and pressure distribution aspects over other features, providing actionable design insights.
+Highlights the importance of form factor optimization for specific use cases (sleep, high-movement activities).

Limitations

The study focused on short-term tactile impressions; long-term physiological data (skin conductance/swelling) was not measured.

Reliability & validity

The study's reliability may be limited by the subjective nature of survey responses and potential variations in how participants interpret tightness and contour. Validity is compromised by the focus on short-term tactile impressions rather than actual long-term physiological responses, as acknowledged by the study's limitations regarding skin conductance and swelling.

Think critically

If 'wearability' means forgetting the device is there, how might this conflict with a brand's desire for the device to be a visible fashion statement?

Design Principles

"The Absence of Sensation Principle: A wearable is most successful when the user loses the constant sensory awareness of its presence."

As wearables move toward 24/7 health monitoring, 'wear-and-forget' comfort is the primary barrier to user retention. Understanding that users prioritize tactile softness and pressure distribution over modular features allows designers to optimize form factors for sleep and high-movement activities.

What This Means for Your Design

If a watch has sharp edges or a tight, solid band, people will stop wearing it within a week, no matter how cool the features are.

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Quick Cite

Paragraph starter

Research by Proceedings of the Human Factors and Ergonomics Society Annual Meeting (2024) suggests that physical discomfort in wrist-wearables is driven more by pressure-related strap tension and sharp edge geometry than by the device's actual weight.

Source

Proceedings of the Human Factors and Ergonomics Society Annual Meeting

User Expectations for Comfort, Discomfort, and Wearability of Wrist-Worn Devices

journal · 2024

View source

Questions About This Research

What does the research say about reducing strap tightness and increasing rounded contours improves perceived long-term wearability?: Fillet all edges that contact the skin with a minimum radius of 2mm and utilize bifurcated or perforated strap designs to allow for skin expansion and sweat evaporation. Evidence: Proceedings of the Human Factors and Ergonomics Society Annual Meeting (2024).
Why does "Reducing strap tightness and increasing rounded contours improves perceived long-term wearability" matter for design?: As wearables move toward 24/7 health monitoring, 'wear-and-forget' comfort is the primary barrier to user retention. Understanding that users prioritize tactile softness and pressure distribution over modular features allows designers to optimize form factors for sleep and high-movement activities.
How can designers apply this research?: Fillet all edges that contact the skin with a minimum radius of 2mm and utilize bifurcated or perforated strap designs to allow for skin expansion and sweat evaporation.
What were the main findings?: Rounded interior casing edges significantly reduce 'digging' sensations during wrist flexion.. Breathable strap materials are prioritized over aesthetic premium materials (like leather) for 24/7 use.. Weight is rarely a complaint unless the device's center of gravity causes it to shift or rotate on the wrist.
What research method was used?: Survey.
How strong is the evidence?: Evidence strength is rated Moderate effect, based on a 2024 journal from Proceedings of the Human Factors and Ergonomics Society Annual Meeting.
What should I do differently in my next project?: Implement adjustable tension systems that allow for 'micro-adjustments' (less than 5mm) to account for daily limb volume changes.
What are the limitations?: The study focused on short-term tactile impressions; long-term physiological data (skin conductance/swelling) was not measured.