APPARATUS FOR THE ANALYSIS AND MEASUREMENT OF MAXIMUM AND EXPOLSIVE STRENGTH OF LOWER EXTREMITY MUSCLES

Abstract

The subject invention is intended for the use of measuring maximum and explosive muscle strength of lower extremities in various positions whereby depending on the position, the strength of individual muscle groups is measured. The apparatus consists of a basic casing (1), a mechanism for securing fastening which consists of a fixator (2) and belt (3), a mechanism for the angular movement of braces and for fastening (4) upon which braces (5) move and are fastened in a desired position, and a pair of braces with a sensor and lining (6), which are fastened and move in the mechanism for the angular movement of the braces (4), whereby linear movement of the braces (5) and angular rotation of the braces (5) are possible in each mechanism for the angular movement of the braces (4) at any angle, preferably at an angle of 90.

Claims

1. The apparatus for measuring maximum and explosive muscle strength of lower extremities comprising a basic casing (1), a mechanism for securing fastening consisting of a fixator (2) and a belt (3), a mechanism for angular movement of braces and for fastening (4) upon which braces (5) move and are fastened in a desired position, and a pair of braces with a sensor and lining (6), which are fastened and move in the mechanism for the angular movement of the braces (4) characterized in that the linear movement of the braces (5) is possible, as well as angular rotation of the braces (5) in each mechanism for the angular movement of the braces (4) at any angle, preferably at an angle of 90.

2. The method for measuring maximum and explosive muscle strength of lower extremities using the apparatus according to claim 1, is characterized in that the method involves the following steps: a) selection of a subject from a database or the input of a subject if not in database, b) selection of the type of test, c) beginning of measurement, which includes positioning the subject in a position appropriate for taking measurements, d) execution of the test by the subject one or more times, desirably twice, e) stopping the test, f) automatic analysis of acquired data, whereby results are compared as being greater than, equal to or less than reference values, and display of the results using software, g) the acquired and calculated data are saved in a database for later use or manipulation.

3. The method for measuring maximum and explosive muscle strength of lower extremities using the apparatus according to claim 1, is characterized in that the method involves measuring the following measuring positions: a) prone isometric hip extension, as shown in the FIG. 4 b) supine isometric hip flexion, as shown in the FIG. 5 c) supine isometric hip adduction, as shown in the FIG. 6 d) supine isometric hip abduction, as shown in the FIG. 7 e) kneeling isometric hip external rotation, as shown in the FIG. 8 f) kneeling isometric hip internal rotation, as shown in the FIG. 9 g) eccentric knee flexor strength, as shown in the FIG. 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The subject invention is demonstrated in the figures that show:

[0035] FIG. 1: the basic assembly of the measuring board

[0036] FIGS. 2a and 2b: show the braces where they can be rotated 90

[0037] FIG. 3: cross section of the apparatus from FIG. 2a and the arrangement of internal components

[0038] FIG. 4: shows the position of the subject for measurement of prone isometric hip extension

[0039] FIG. 5: shows the position of the subject for measurement of supine isometric hip flexion

[0040] FIG. 6: shows the position of the subject for measurement of supine isometric hip adduction

[0041] FIG. 7: shows the position of the subject for measurement of supine isometric hip abduction

[0042] FIG. 8: shows the position of the subject for measurement of kneeling isometric hip external rotation

[0043] FIG. 9: shows the position of the subject for measurement of kneeling isometric hip internal rotation

[0044] FIG. 10: shows the position of the subject for measurement of eccentric knee flexor strength

EMBODIMENT OF THE INVENTION

[0045] The apparatus for measuring the maximum and explosive strength of lower extremity muscles comprises three basic subsystems: the basic casing (1), movable carriers with sensors (6) and measurement software. The basic casing (1), has a mechanism for securing the fastening comprising a fixator (2) and belt (3). The moveable braces (5) can be moved along a mechanism for angular movement of the braces (4) and for fastening, and are fastened in a selection position using a special fastening mechanism. The braces (5) contain a lining and a single-axis sensor (6), which measures the forces generated during measurements. The subject invention enables the linear movement of the braces (5), and the angular rotation of the braces (5) in each mechanism for the angular movement of the braces (4) at any angle, preferably at 90.

[0046] In that manner, enabling linear and angular rotation of the braces allows for the measurement of maximum and explosive muscle strength of lower extremities for a larger number of different positions of a subject, which enables the measurement of several muscle groups as will be shown in the below-stated measurement examples.

[0047] Examples of Measurement Positions and Acquired Experimental Data

[0048] Thirty football players (19.12.1 years of age; 1.790.05 m; 74.43.1 kg) participated in the research. None of the participants had injuries of the lower extremity muscles during the last 12 months. All test procedures were approved by a university's ethical committee for human research. Before testing, all participants or their parents (if <18 years old) gave written consent after all procedures were explained.

[0049] Participants visited the laboratory twice, with a 5-day break in between. Each testing procedure consisted of a 15-minute warm-up and measurement of isometric strength of seven different muscle groups by using the apparatus. The strength tests are the following: prone isometric hip extension, supine isometric hip flexion, supine isometric hip adduction, supine isometric hip abduction, kneeling isometric hip external rotation, kneeling isometric hip internal rotation, and eccentric knee flexor strength. Two rounds of testing were conducted for each strength test, whereby the pause between repetitions was 60 seconds, and 120 seconds between tests. The sequence of the testing was randomized.

[0050] Prone isometric hip extension test (FIG. 4) was performed as follows. Participant was lying prone on the apparatus with one leg attached on the hook of the apparatus at the level of malleoli, and the other leg resting on the apparatus. A Velcro strap was used to stabilize the pelvis onto the apparatus. When ready, the participant performed maximal isometric hip extension with knee fully extended. Each leg was tested twice in randomized fashion.

[0051] Supine isometric hip flexion (FIG. 5) was performed as follows. Participant was lying supine on the apparatus with one leg attached on the hook of the apparatus at the level of malleoli, and the other leg resting on the apparatus. A Velcro strap was used to stabilize the pelvis onto the apparatus. When ready, the participant performed maximal isometric hip extension with knee fully extended. When ready, the participant performed maximal isometric hip extension with knee fully extended. Each leg was tested twice in randomized fashion.

[0052] Supine isometric hip adduction (FIG. 6) was performed as follows. Participant was sitting on the apparatus with both legs extended, attached on the hooks of the apparatus at the level of malleoli. When ready, the participant performed maximal bilateral isometric hip adduction with knees fully extended. Both legs were tested simultaneously twice.

[0053] Supine isometric hip abduction (FIG. 7) was performed as follows. Participant was sitting on the apparatus with both legs extended, attached on the hooks of the apparatus at the level of malleoli. When ready, the participant performed maximal bilateral isometric hip adduction with knees fully extended. Both legs were tested simultaneously twice.

[0054] Kneeling isometric hip external rotation (FIG. 8) was performed as follows. Participant was kneeling on the apparatus with hip and knee angles at 90 degrees, and with both legs attached on the hooks of the apparatus. When ready, the participant performed maximal isometric bilateral hip external rotation without moving knees or spine. Both legs were tested simultaneously twice.

[0055] Kneeling isometric hip internal rotation (FIG. 9) was performed as follows. Participant was kneeling on the apparatus with hip and knee angles at 90 degrees, and with both legs attached on the hooks of the apparatus. When ready, the participant performed maximal bilateral isometric hip internal rotation without moving knees or spine. Both legs were tested simultaneously twice.

[0056] Eccentric knee flexor test (FIG. 10) was performed as follows. Participant was kneeling on the apparatus, with the lower legs attached to the hooks of the apparatus at the level of malleoli. Arms were placed across the chest. When ready, participant slowly lowered the body towards the floor, while avoiding flexion of the hip. In case the participant could not lower his body under control, he was allowed to fall into the push-up position by placing the palms on the floor. Both legs were tested simultaneously twice.

[0057] Force data of all seven muscle strength tests were transferred to the computer at 1000 Hz through a 16-bit recording unit and stored for later analysis. The trial with the highest peak force in each test was used in further analyses. Descriptive statistics (means and standard deviations) for all force variables were calculated. Systematic bias was assessed using a t-test for dependent samples. Test-retest reliability for all tests was calculated using an intra-class correlation coefficient. All statistical analyses were done using a SPSS 15.0 software (SPSS Inc., Chicago, Ill., USA). Level of statistical significance were set at p<0.05. As there were no significant between-limb differences in maximum isometric force (all p >0.05), only descriptive and reliability data for dominant (i.e. kicking) leg will be reported.

[0058] Descriptive statistics and test-retest correlation coefficients for all force variables for the dominant leg are presented in Table 1. No significant differences in maximum isometric force between the first and second measurement were observed for any of seven tests (all p >0.05).

TABLE-US-00001 TABLE 1 Means, standard deviations (SD) and intra-class correlation coefficients (ICC) for all seven strength tests measured on the apparatus. First Second measurement measurement Test (mean SD) (mean SD) ICC Prone hip extension (N) 283.7 65.3 274.4 63.4 0.85 Supine hip flexion (N) 180.2 39.9 185.4 39.7 0.91 Supine hip abduction (N) 213.6 42.3 212.9 41.1 0.88 Supine hip adduction (N) 238.4 29.4 235.1 31.2 0.93 Kneeling hip external rotation (N) 121.7 25.6 126.0 24.9 0.87 Kneeling hip internal rotation (N) 134.7 27.5 137.2 26.6 0.85 Eccentric knee flexion (N) 334.6 46.5 318.9 48.3 0.86

[0059] From the data presented above, the apparatus displays no significant systematic error and high level of test-retest reliability for all seven strength tests. It should be noted that the obtained test-retest reliability coefficients for selected strength tests are similar to those observed with expensive laboratory isokinetic hip or knee strength measurements (Almosnino et al. 2011; Julia et al. 2010; Maffiuletti et al. 2007). Almosnino S, Stevenson J M, Bardana D D, Diaconescu E D, Dvir Z. Reproducibility of isokinetic knee eccentric and concentric strength indices in asymptomatic young adults. Phys Ther Sport. 2012 August; 13(3):156-62; Julia M, Dupeyron A, Laffont I, Parisaux J M, Lemoine F, Bousquet P J, Hrisson C. Reproducibility of isokinetic peak torque assessments of the hip flexor and extensor muscles. Ann Phys Rehabil Med. 2010 June; 53(5):293-305 and Maffiuletti N A, Bizzini M, Desbrosses K, Babault N, Munzinger U. Reliability of knee extension and flexion measurements using the Con-Trex isokinetic dynamometer. Clin Physiol Funct Imaging. 2007 November; 27(6):346-53.

APPLICATION OF THE INVENTION

[0060] The subject application is intended for use for the measurement of maximum and explosive muscle strength of lower extremities in various positions whereby, depending on the position, the strength of individual muscle groups is measured. Persons skilled in the art will find it obvious that various changes and modifications to the described apparatus and method according to this invention can be made, without departing from the scope or essence of the invention.