Is there a good way to attach the EKG sensor to the stationary arm of the Goniometer so the sensor box is out of the way during experiments?

3M sells tape that is 1 inch wide that works well for this application. The tape is called called Dual Lock(TM) Reclosable Fastening System.

The online order code is 3M# S-15826

Apply one piece of tape with hooks to the EKG Sensor, order code EKG-BTA, $147, then place the corresponding piece of tape with loops to the stationary arm of the Goniometer, order code GNM-BTA, $159. You can then lock the EKG sensor to the Goniometer during the experiment.