Making Back Pain A Distant Memory The Mobex

In many cases, a physical therapy training device for back injuries is not effective, mainly due to the fact it is impossible to create a comfortable position that does not cause pain, making rehabilitation and training less effective.

In addition the problem of the heavy weight (weighs about 400kg) and the large dimension of the machine means that the device is not mobile. The customer was looking for help in creating a machine where the user could be secure and stable – initial consultation and set up taking about 30 minutes by a specialist – and subsequent visit could be set must be within minutes.

Working alongside Onder de Linden bv, ERIKS were involved in the development of a unique physical therapy device for effectively treating back pain – The Mobex.

The Issue

The designers were looking to reduce additional strain and further injury when patients were undergoing rehabilitation treatment on their backs - more specifically lower atypical back injuries. Traditional weight machines help strengthen the back however, the all purpose design of the seat does not provide core stability for the back allowing the user to move which could result in damaging the vertebrae further, particularly on the upward return stroke.

The Solution

Working to improve the design of traditional fitness equipment, ERIKS engineers were tasked with improving patient support through redesigning the seat. By adding adjustable knee supports, equipping these and the seat with linear actuators allows the machine to be adjusted precisely to the desired position for the patient whilst providing the necessary stability.

Due to the weights used, the device is quite large and heavy,  as a result of weight and gravity, the training force is only in one direction.  ERIKS engineers developed an AC servo generator/motor with bespoke software. So now the device is smaller and bidirectional. During the move, depending on the position of the back, it is possible to create a profile instead of only one force.

In addition a rotary actuator was applied to the weights to eliminate injury on the return stroke due to gravitational force.

The Products

  • Five linear actuators with amplifiers
  • One servo generator/motor amplifier
  • A printed circuit board and PC with dedicated software designed by ERIKS
  • All system components communicate by means of CANopen fieldbus system