A Validation Study of Force Sense Measurement

The term proprioception was first introduced by Sherrington in 1906, who described it as a type of feedback from the limbs to the central nervous system. Based on the early descriptions by Sherrington and others, the contemporary terms of joint position sense (JPS), kinaesthesia (perception of active and passive motion), and sense of tension or force sense are considered sub modalities of proprioception.

For the extremity joints, goniometers (universal, bubble, digital) can also be used to measure active JPS. Depending on the device used and the extremity joint measured, reliability and measurement error of active movement goniometry can range widely and this should be carefully considered if goniometry is used to measure active JPS of extremity joints. Kinesthesia, can be measured by calculating the passive motion detection threshold of individuals.

The force sense (FS), commonly assessed using force reproduction, has also been used as a measure of proprioception. Assessing force reproduction by limb matching involves the use of a reference force, usually determined as a percentage of a Maximal Voluntary Isometric Contraction (MVIC), and attempting to replicate that force.

Proprioception can be decreased in those who suffer from knee injury. Because patients with severe degenerative joint disease often require total knee arthroplasty to relieve pain, improve stability, and restore function. Due to problems such as oedema, immobilization and subjective pain after surgery, it is difficult to evaluate proprioception with joint repositioning method. In such cases, the assessment of FS could be of particular interest in the knee region. FS can also be measured by the accuracy of reproducing a specific target force. For example, the pressure biofeedback device (PBD) used for assessing the cranio-cervical flexion test could be considered a method of assessing force sense in the cervical spine. The ability to hold steadily or the accuracy in achieving and maintaining a desired pressure can be used. However, for the knee region, there is no method to measure the force sense via a device that can be used in clinical practice.

The aim of this study was to establish a method for measuring FS that could be applied quickly and practically in the clinic, and to correlate the outcomes with surface electromyographic (EMG) muscle activation levels from M. Quadriceps femoris to demonstrate the applicability and objectivity of this method.