As seen at NECE/ErgExpo in Las Vegas and IEA in Florence Italy.

INSTRUCTIONS - Simple MAE (Maximum Acceptable Effort) Calculator:

1.)  Enter Cycle Time (up to 250 sec)

2.)  Select Force Type

3.)  Enter Force Duration (i.e., "hold time" in sec)

4.)  Enter Count (i.e., # efforts per cycle)

5.)  Choose Posture Modifier (note that working in awkward posture, the person's ability to apply force is reduced ... this is a simple subjective posture modifier)

Output Duty Cycle is simply the % of cycle that the force is applied.


Output Force Limit is the acceptable force such that 75% of female population and approximately 100% of the male population can perform the task without experiencing localized muscle fatigue.


1.)  Enter Cycle Time (up to 250 sec)

2.)  Select Force Type

3.)  For up to 3 tasks of the selected Force Type enter the Force Magnitude (lb), Force Duration (i.e., "hold time" in sec), and Count (i.e., # efforts per cycle).

Output Recovery - Model is the calculated RCRA (Recommended Cumulative Recovery Allowance) model recovery time. This is the recovery time (in sec) needed to recover from the forces applied during the cycle.

Output Recovery - Actual is the actual recovery time within the cycle. This is the time within the cycle that force is not being applied, and muscles are in a state of recovery.

Output RCRA Ratio value is the ratio of Recovery-Model to Recovery-Actual. A RCRA Ratio < 1.0 is "good", meaning there is sufficient in-cycle recovery time such that 75% of female population and approximately 100% of the male population can perform the tasks without experiencing localized muscle fatigue.

This nifty app calculates acceptable hand force limits. These force levels are acceptable for 75% of females and approximately 99% of males.

Mobile Version


INSTRUCTIONS - Strain Index Calculator:

1.)  Select Intensity of Exertion

2.)  Select Duration of Exertion

3.)  Select Efforts Per Minute

4.)  Select Hand/Wrist Posture

5.) Select Speed of Work

6.) Select Duration per Day (in hours)

Output Strain Index a metric related to the relative risk of distal upper extremity disorders. A lower Strain Index score is better than a high score. This metric can be used to compare jobs to each other, and to measure the degree of improvement post-solution.


+1 (334) 502-3562
311 N College Street, Auburn, AL, USA
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