THE SHOULDER: ASSESSMENT OF PROPRIOCEPTIVE CAPACITY USING NMT
Area Zenit, Torino,
Continuing our testing of NeuroMuscular Taping as a technique to aid rehabilitation, an initial dataset was collected with the aim of recording changes in the proprioceptive capability (PC) of the upper limb obtained through the application of different NeuroMuscular Taping constructions. The study was conducted in five males, aged 40 to 45 years, who did not present particular pathologies of the shoulder joint.
The study set out to analyze changes in average trace error (ATE) values and in test execution time and the relationship of these changes to the construction applied. Each subject performed five tests in five different application conditions:
- without tape;
- deltoid muscle: decompressive tape applied in a “y”-shaped configuration (figure 1a);
- deltoid muscle: compressive tape applied in a “y -shaped configuration (figure 1b);
- deltoid muscle: tape applied in a double-fan configuration (figure 1c);
- deltoid muscle: compressive tape in a double “I” configuration (figure 1d);
Deltoid muscle: decompressive tape in a “y”-shaped configuration (a); compressive tape in a “y”-shaped configuration (b); tape applied in a double-fan configuration (c); compressive tape in a double “I” configuration (d).
The sequence of these applications varied from subject to subject in order to limit the learning effect between one test and another. Finally, 30 minutes after the end of the tests, the subjects underwent a sixth test without tape to allow a further comparison of data, this time in a situation in which the facilitation deriving from repetition of the test is thought (according to the literature) to be reduced to a minimum. The arm of the test equipment was blocked at 180° in order to limit variables due to possible flexing of the elbow; elbow flexing would, indeed, invalidate this exercise which targets the shoulder joint (figure 2).
Close-up of an upper arm resting on the anthropomorphic arm of the robot.
Since the aim of the study was to evaluate the subjects’ coordination or dexterity, it was important that the exercise should not involve the generation of muscle force; for this purpose, we used one of the functions of the system which relieves the joint of the weight of the arm. The system exerts an upward force which can be adjusted with extreme sensitivity and precision, thereby allowing the necessary annulment of the load on the joint in relation to the characteristics of the particular neuromuscular exercise.
For evaluation purposes, we considered the ATE, the execution time and the relationship between the two. The numerical data collected showed a marked reduction in the ATE; from 33% to 26% i.e. –7%. This is a noteworthy result for this type of exercise given that, on average, recovery of PC in subjects treated with daily sessions that include, among other exercises, at least 30 minutes of work aimed at recovery of PC, is 8-10% after the first 20 days of treatment, subsequently stabilizing at the values obtained in this test after around 40-60 days of treatment. The data collected, though partial, are encouraging and show a substantial and immediate increase in the individual’s PC, corresponding to an average value of 7.5%.
These findings lend weight to the idea that application of the NeuroMuscular Taping technique may increase the therapeutic possibilities in all individuals presenting with proprioceptive and kinesthetic deficits in the context of acute and chronic disorders, surgically or conservatively treated, as well as in all less severe clinical cases, and also in corrective and preventive interventions in sport.
The work done with these five subjects seems to show that with NeuroMuscular Taping it is possible to obtain a 7.5% improvement in the ATE value; in addition, the increase in the capacities studied seems to demonstrate that use of this technique, which ensures continuous stimulation, also allows the maintenance of better quality neuromuscular control, and thus movement, even outside the rehabilitation sessions themselves, thereby reducing overall recovery times.
One of the objectives of the working group is to continue this research into proprioception, increasing the study sample, taking into account changes introduced by other data from similar investigations of this kind, evaluating points of weakness, and examining the rules of this particular research method, specifically, changes in PC as a function of tape construction.
Functional proprioception assessment
The subjects underwent a functional evaluation performed using a proprioception assessment system that is particularly suitable for assessing the rotator cuff, both for orthopaedic and for sports rehabilitation purposes. The equipment has an anthropomorphic robotic arm which is able to move the patient’s arm in the three-dimensional joint space as well as a monitor linked to a computer.
The subject is seated in front of the monitor in an ergonomic position, resting evenly on both knees and with his back erect and supported by a back rest; the right hand holds the mechanical arm, while the left hand holds a handle. To avoid errors of approximation, this position is rendered perfectly reproducible through the use of a set of graduated and numbered mechanisms, which can be adjusted (figure 1).
Proprioceptive system: the subject’s arm rests on the anthropomorphic robotic arm.
The test involves moving the upper limb/hand in order to move a cursor on the monitor screen. First, the cursor must be made to follow a reference line within a circular area (figure 2a), and then an irregular path made up of three oblique lines (figure 2b).
Lines drawn in the circular (a) and oblique line (b) tasks.
In the first of these tasks, the subject is required to execute five complete revolutions; in the second, three repetitions. In the first task, starting from the center of the image (marked by a cross) the cursor is moved over the red indicator (start of the assessment); then, executing a circular movement of the upper limb, and thus a rotatory movement of the cursor, the subject follows, to the best of his ability, the blue reference line (ideal kinesthetic line) within the specified area; in the second task, the cursor must be made to follow the red line, moving from the yellow to the green point; the difference between the line drawn by the cursor and the reference line provides a measure of the proprioceptive sensitivity of the arm being examined. This difference is expressed, as a percentage, by a numerical value termed average trace error (ATE). In the context of assessment of this type of exercise (a vast and complex area), ATE is one of the available indices that identify PC. Using this system, it is possible to obtain a set of functional parameters useful in the more complex and detailed evaluation of fine arm coordination. The standard normal value of the ATE is 20%; values above this need to be investigated and studied, for rehabilitation purposes. Figure 3 shows two examples of completed tests.
Examples of completed tests.