A Simple Non-invasive Method for Temporary Knockdown of Upper Limb Proprioception

The overall objective of this protocol is to demonstrate a practical method to temporarily interfere with proprioception in the upper limb of healthy humans. This video describes the materials needed, the procedure for the protocol as well as representative results from carrying out this protocol. The materials used in this protocol include:a two and a half inch wide strap, a rubber band, a permanent marker, and a cordless 183 hertz vibrator.

This protocol is intended to reduce proprioceptive acuity in the upper limb of healthy humans. For this protocol the head of the vibrator is placed in the ulnar groove just superior to the line between the olecranon process of the humerus and the medial epicondyle of the ulna. To locate the placement for the head of the vibrator palpate the ulnar nerve in the ulnar groove between the olecranon process and the medial epicondyle.

Place an x just superior to them. Place the head of the vibrator onto the marked location with the handle of the vibrator superior to the head. Apply a strap around the handle of the vibrator and the participant's arm.

Apply a rubber band around the head of the vibrator to ensure its connection with the surface of the skin. Have the participant bend and straighten their elbow. If they report interference adjust the straps and rubber band so that freedom of movement is ensured.

Turn the vibrator on and wait for two minutes prior beginning your measurement of upper limb kinesthetic sense. In this experiment, with the vibrator still on, proprioceptive performance was quantified using the tablet version of the Brief Kinesthesia Test which is under development in our lab. The tablet version of the Brief Kinesthesia Test includes 20 routine trials with visual occlusion per upper limb.

Absolute error in the distance for the target is quantified and is thought to reflect kinesthetic sense. The tablet version of the Brief Kinesthesia Test involves a sensory input, which is the examiner's guidance of the upper limb to the target. Central processing, in which the participant tries to remember the spatial location of the target, and a motor output, which is the participant's attempt to locate the target after guidance has been removed.

These three elements are thought to be necessary in a measure of overall proprioceptive performance. The materials needed to determine the vibration detection threshold include:a 128 hertz tuning fork, a stopwatch, a textbook, a standard-height table and chair, and a pen. Using a permanent marker color the bottom one millimeter around the stem of the tuning fork.

This mark is used to standardize the depth and therefore the pressure of the tuning fork application during the test. Mark a dot on the skin over the distal biceps tendon one centimeter superior to the crease in the elbow. Place a textbook at the edge of the table close to the participant, the textbook provides a firm but compliant surface on which to strike the tuning fork.Good.

Read the instructions to the participant. This is test of your ability to detect vibration. Now I will put this tuning fork ion your biceps tendon.

Please tell me if you feel any vibration, then say now immediately when the sensation of vibration disappears. This procedure will be repeated three times. For this protocol the vibration detection test was conducted immediately after removal of the vibration which had been on the arm for five minutes.

To administer the vibration detection test the examiner holds the stem of the tuning fork loosely between the thumb and index finger and strikes it on the book inside of the square target with enough force to produce resonance. Immediately after striking the tuning fork, it's placed on the test location using enough pressure to depress the skin and conceal the one millimeter band on the tuning fork from vision. Using the stopwatch you quantify the time from the placement of the tuning fork on the participant's skin, until the participant no longer feels the vibration and says now.

This procedure is repeated two more times on that arm. Here we present representative results. Using the protocol presented here we tested 20 healthy adults who had no known pathology of the upper limbs.

Each participant was tested using the two measures at two separate sessions which were one week apart. At session two participants completed the same measures under the condition of temporary proprioception knockdown. A repeated measures design evaluated the vibration detection threshold test, retest, reliability.

The Pearson correlations were 0.64 and 0.61 for the right and left upper limbs respectively The intraclass correlation coefficients were 0.77 and 0.76. To test the directional hypothesis that proprioception knockdown using vibration would result in proprioception impairment, one-tailed paired t-tests were used to compare mean error between week one, week two, and the proprioception knockdown conditions for the VDT and the BKT. The proprioception knockdown protocol resulted in statistically poorer scores on the VDT and the BKT for both upper limbs, while the control conditions were not statistically different.

The extent of proprioception knockdown that resulted from the protocol was quantified by calculating effect size. The effect size on the vibration detection threshold was large, while the effect size for the Brief Kinesthesia Test was moderate. In summary high frequency vibration is successful in reducing upper limb proprioceptive acuity.

This could be used in the development and testing of limb proprioceptive measures, it is simple to administer, comfortable for participants, and practical.