Health Worker Back Injury

Nursing and other hospital work are among the most dangerous jobs in the United States. More nurses miss work due to on- the- job injury per-capita each year than firefighters, construction workers and police officers.

35,000 miss work due to back injury each year*

* NPR News, 2017

83% Reported working with back pain* 

*American Nurses Association, 2013

Measure your back activity

t8 is a wearable back monitor which uses electromyography to measure weight loads on the back. 

14 lbs







43 lbs







Alerts you before dangerous lifting loads

EMG predictive load analysis measures a spike in the electrical activity of the back muscles, giving a haptic warning before lifting a dangerous amount of weight.  

A guide on your path to better back health

t8 is paired with a mobile app which uses principals of behavior change to help reinforce habits leading to improved back health. 

Actionable data for hospitals to improve working conditions

Hospitals frequently  end up footing the bill for on- the job injury. Insights gathered from device data can be used to identify when, where, and how frequently workers are being injured. This affords a more granular picture of workplace injuries allowing interventions to effectively target opportunities to reduce the instance of employee injury.

Single Device,

Flexible Configuration


a. Chest Strap

b. Bra Clip 

What are the causes of back injury?

Secondary research points to repeated lifting of heavy loads as the primary cause of back injury among hospital workers. The the most common tasks included handling patients and moving equipment. I focused specifically on nurses, generating a comprehensive list of behaviors which may lead to back injury over time.


Primary Research

Conversations with ergonomists, nurses, union representatives, and public health workers helped to develop a more complete understanding and empathy for the needs and constraints of the major stakeholders. 


“It's an active environment. We're on our feet all day, we don't stop

“Our minds are on patients, not our own safety”

"If we knew in advance we could stop and re-assess our plan"

"The thing I'm most of afraid of is a career- ending back injury"

Fail Quickly

Make it. Give it to the User. Break it. Repeat.


Weight load, not posture

Workers should not lift any weight above 35 lbs. Regardless of the individual's conditioning or mechanics, repeated lifts will eventually cause overuse injury.


Assistive lifting equipment is 

frequently unused

Nurses reported that they are primarily focused on patient wellbeing, as opposed to taking care of their own health. Slings and other lifting equipment have been successful at reducing injuries to hospital workers, but aren't always used by hospital staff when handling patients 


Poorly equipped hospitals

Hospitals often neglect ergonomic safety considerations for workers. Many hospitals lack equipment which is considered essential in reducing on- the- job injury.

Project Goals

Phase 01: How to we measure actions that leads to back injury?

Phase 02: How do we change behavior which leads to back injury

Hardware Strategy 

Promising methods of measuring user weight loading were vetted for feasibility through a set of criteria including demands of workers and constraints of the hospital environment.


Back Pad Configuration



2 Pad

1 Pad



Concept Selection

Consulting with the university kineseology department and peer reviewed articles highlighted the possibility of loading measurement through EMG analysis of the Erector Spinea muscle between T8 and T12.


Technology Validation

The core technology was validated though a proof- of- concept built with EMG sensors and arduino uno interface. 

Comp 1_1.gif

"bumps into my spine"

"Too Wide"

"Definitely my favorite"

Learning by feeling

Proof of concept prototypes were generated and tested on users to guide the direction of development.


Learn By Feeling

User Testing

Interface of the product with a wide spectrum of user back geometries was key. Three primary variations were explored through user testing measured for comfort, stability and reliability of diode contact.

Split Pad

Single Pad

Single Pad, Flexible

Comp 1_3_1.gif
Comp 1_4_1.gif
Comp 1_2_1.gif
Comp 1.gif

The split- pad version was selected, as its flexibility offered a greater degree of comfort for the greatest variety of users. 


Compatibility with Bra Types

To ensure the viability of a bra clip sensor, each iteration was tested on a wide range of bra designs. 


Haptic Warning


Predictive load analysis paired with haptic feedback creates opportunities for users to self-monitor behavior and facilitate positive behavior change.

The Sensor Pad

Positive Diode

Negative Diode

Ground Diode

EMG sensors detect your back muscle electrical activity, interpreting this data to determine if you are lifting a harmful amount of weight

Integrated Architecture

Embodying a truly gender- ubiquitous design started with a female- first approach. The rigid, soft-touch sensor pad hinges from the support structure, sliding under and clamping onto the back of a bra strap.




Sensor pads gently press against the contours of the users' paraspinal muscles, bending and flexing to the back's dynamic surface.