In addition to the RHEDglove, ErgExperts has utilized thin-film force and pressure insoles to measure changes in plantar foot pressure while climbing and walking. Thin-film force and pressure sensors have also been used to determine the force and pressure across the shoulder from various types of backpack and satchel strap designs.

Muscle activity measurement - Electromyography (EMG)

To measure the activity (contraction) of a muscle or muscles, one can use surface EMG electrodes. These self-stick bandage type electrodes are placed over the belly of the muscle that one wants to measure. As the muscle contracts, small electrical potentials are generated, and these can be picked up by the surface electrode and recorded using specialized monitoring equipment. Using this type of equipment allows one to compare the muscle activity associated with one type of product vs another to determine which one induces the lesser amount of muscle activity. Special protocols, analyses, and equipment can also allow for the prediction of muscle fatigue or the degree of fatigue in a particular muscle. The EMG system allows for the simultaneous measurement of up to 16 different muscle sites while the subject is untethered to the equipment. This type of system has been utilized with letter carriers to examine the muscle activity associated with the lower extremity while using different methods of transporting mail.

Joint motion measurement - Goniometry

To evaluate the motion requirements of a task or those induced through product use, an electronic goniometer can be used over a specific joint. There are various goniometer designs available, and the selection of which type to use is based on the joint or joints that need to be measured and the work or testing environment. Specific goniometric systems are available for the major joints of the body including the hand, wrist, elbow, knee, shoulder, neck, and back. Based on data from goniometric studies, the question of how long someone spends in non-neutral postures, the range of postures, the maximum postural deviation, as well as the velocity and acceleration of joint motions can be determined and compared to ergonomic guidelines.

Physical Workload Evaluation - Heart-rate monitoring

The estimation of a task's energy or physical workload requirement can be made easily with precision heart-rate monitors. Heart-rate monitors are just a special type of EMG equipment that have been designed to allow for the measurement of heart rate. These monitors can collect information on the inter-arrival rate of each heartbeat or record the average heart rate at intervals that range from 5 seconds to 1 minute.

Workload estimates based on heart-rate data can be used to identify:

• potential heat stress or exposure problems in hot working environments
  
  
• jobs or activities that have high or heavy workloads so that they may be redesigned so a greater percentage of the population can perform them
  
  
• different effort levels between jobs, tasks, work methods, or techniques
  
  
• jobs for individuals who are returning to work after prolonged illness
  
  
• the potential for fatigue

Heart-rate data has also been used to classify the physical fitness level of workers in addition to classifying the job demands. Pre-employment screening programs typical include objective heart-rate analysis to classify both the job demands and the fitness level of the applicant.