Quick-Release Appartatus
Core Quick-Release
Fast trunk muscle responses to perturbations are important to avoid back injury. The quick-release apparatus along with electromyography (EMG) measures a person's trunk muscle reflexes responding to a sudden, load release. In this task, participants pull against a cable at a specified force level. Without warning, the resisting force is released with an electromagnet and EMG signals from the trunk muscles are recorded.
Extremity Quick-Release
This video provides two demonstrations of a quick release trial. An electromagnetic provides resistant to the cable attached to the participant while a monitor (not seen) displays both the participant's force and a desired force. Before the task begins, the participant is instructed to produce the desired force and then prevent their leg from moving forward when the magnet is released. Once the desired force is reached, the lab personnel releases the magnet without giving advanced notice to the participant.