Shoulder Joint Injury Research Articles

体表マーカの偏位と肩甲骨運動のin-vivo計測

Diagnosis of a shoulder joint injury, particularly one brought about during sports activities, necessitates measurement of its motion accurately and noninvasively. Conventional measurement of shoulder joint movement, however, deals solely with relative movement between humerus and thorax, neglecting other components of the joint. We have focused on 6-DOF measurement of scapula movement relative to the thorax, a subdominant component of shoulder movement. Such motion data, however, cannot easily be obtained by means of a marker-based motion-capture system, due to the skin mobility relative to the skeleton. The objective of this study was to validate measurement accuracy of scapula movement when measuring markers are attached to the skin above the scapula’s bony landmarks.We employed an open MRI (Magnetom Open, Siemens, Germany) to measure the shoulder joint and markers attached to the subject’s skin. Five and three markers were attached to the skin above the scapula and thorax, respectively. Three volunteers (24.0±2.64 years old), who possessed no distinct kinetic dysfunctions in their shoulders, served as subjects, in this preliminary study. Their shoulder movements were sampled at three humeral elevation angles (0°, 90°, 150°) on a frontal plane by open MRI. In order to reduce the skin mobility, the same movements were recorded, using a more accurate method in which the scapula’s markers were relocated into correct positions, determined through the palpation of an experienced physical therapist, at each humeral elevation. In an attempt to validate the skin mobility, we measured the deviation of the markers from the scapula’s bony landmarks during humeral elevation. Next, the scapula movements were estimated by two different methods as follows: the registration technique using bony shape and the least squares method using the set of markers.The results demonstrated that the deviation of the markers could be reduced into less than or equal to 19.0 mm if the markers were remounted at each elevation angle. Using the remounted markers, we verified the estimated error of position and orientation of the scapula to lie within 10.1° and 6.4 mm, respectively.In conclusion, we validated measurement accuracy of the scapula movement using skin markers above the scapula’s bony landmarks. The results showed that a motion-capture system is capable of quantitatively measuring the static shoulder joint movement with the scapula.

Arthrosonography of the Shoulder Joint for Evaluation of the Glenoid Labrum, Glenoid Rim and Humeral Head: Comparison with Conventional Ultrasonography and MR Arthrography

Purpose: To compare the diagnostic role of arthrosonography, conventional ultrasonography and MR arthrography in the assessment of glenoid labral tear, glenoid rim fracture and humeral head fracture of the shoulder joint. Materials and Methods: The findings of arthrosonography, conventional ultrasonography and MR arthrography were prospectively evaluated in 62 consecutive patients with chronic pain or a history of recurrent dislocation of the shoulder joint. The glenoid labrum was arbitrarily divided into four quadrants: anterosuperior, anteroinferior, posterosuperior, and posteroinferior, and for each, visibility at arthrosonography and conventional ultrasonography was subjectively scored as one of four grades. By means of statistical analysis, the two techniques were then compared. Twenty-six patients subsequently underwent arthroscopy, and the presence or absence of labral tear, glenoid rim fracture and humeral head fracture was determined. The sensitivity and specificity of each modality were separately calculated for each of the three types of shoulder joint injury, and observed differences in these findings were statistically analysed. Results: For all individual quadrants of the labrum, visibility at arthrosonography was higher than at conventional ultrasonography (p.05), though its specificity was significantly higher (p=.003). In this respect, there was no significant difference in sensitivity or specificity between arthrosonography and MR arthrography (p>.05). For the detection of glenoid rim and humeral head fracture, there were no statistical differences in sensitivity and specificity between the three imaging modalities (p> .05). Conclusion: Compared with conventional ultrasonography, arthrosonography provides higher visibility of the labrum, thus improving the capacity of ultrasonography to detect labral tear. Arthrosonography could therefore be useful in the diagnosis of labral tear, glenoid rim fracture and humeral head fracture, and may thus partially replace MR arthrography.

재활운동치료가 견관절 손상 야구투수들의 주관적 통증정도와 등속성 외전/내전력에 미치는 효과

The purpose of this study was to investigate the changes of pain degrees and musculoarticulation functions in 8 baseball pitchers with shoulder joint injuries after the 12 week rehabilitative exercise therapy. 1. Before the rehabilitative exercise therapy, the pain degrees felt at the shoulder involved side were 2.87(±0.64), which showed between `severe` and `fair`. But it decreased after the 12 week rehabilitative exercise therapy. According to the pain scale, the 2nd(14.63%), 4th(29.26%), 6th(29.96%), 8th(60.97%), 10th(64.45%) and 12th(65.16%)weeks were decreased. However, only the 8th(60.97%), 10th(64.45%) and 12th(65.16%)weeks were statistically significant decreased and the pain degree in last 12th week was presented `no or mild pain`. 2. Before the rehabilitative exercise therapy, the musculoarticulation functions of the shoulder involved side was very decreased than the uninvolved side. But most of these variables were increased after the rehabilitative exercise therapy. The PT and PTBW of involved side abductor at 60d/sec were significantly increased 31.49%, 28.57% respectively. The PT and PTBW of involved side adductor at 60d/sec were significantly increased 38.65%, 36.14%. The PT and PTBW of involved side abductor at 180d/sec were significantly increased 26.75%, 24.33% respectively. And the acceleration time was significantly decreased 25%. The PT and PTBW of involved side adductor at 180d/sec were significantly increased 37.09%, 34.15% respectively. And the acceleration time was significantly decreased 28.57%. The PTBW of involved side abductor at 300d/sec was significantly increased 55.88%. The PT and PTBW of involved side adductor at 300d/sec were significantly increased 38.95%, 36.33% respectively. And the acceleration time was significantly decreased 41.66%. In conclusion, the rehabilitative exercise therapy performing during 12 weeks in this study was affected positive changes of pain degrees and muscular function in injured baseball pitchers. Therefore we think that the rehabilitative exercise therapy of this study seems to be available method for baseball pitchers with shoulder joint injuries.

投球動作解析システムによるＴＯＰポジションの運動学的解析

Baseball pitching involves a complicated and rapid movement that has been investigated to prevent injuries and to improve the pitching performance. It is difficult to assess the pitching motion with high accuracy and a high sampling rate, due to the limitations of preexistent camera systems. The current camera system, however, has enough capacity to measure pitching motions with high accuracy and a high sampling rate.We have been diagnosing shoulder joint injuries caused by pitching. The patients (N = 939) felt pain during the pitching sequence as follows: top position (32.5%), maximum external rotation (27.2%), and ball release (14.5%). Hence the top position is one of the most important postures to investigate the mechanisms of shoulder joint injury in pitchers. There have been no studies that focused on the top position, however.The main purpose of this study was to develop a system to assess the pitching motion accurately. Another purpose was to estimate the instant of the top position and evaluate the kinematics of the shoulder and elbow joints.Pitching movement was assessed using a motion capture system (ProReflex MCU500, Qualisys Inc., Sweden) in a studio that has an official pitcher’s mound and home base. This system can record the positions of reflective markers at 500 Hz using seven CCD cameras. Thirty-two markers were mounted on the joints and body landmarks of each subject. Two markers were mounted on the ball. The pitching motions of eleven subjects were assessed, after a period for warm up. Kinematics parameters were calculated using three-axis gyroscopic Euler angle.The instant of the top position was observed for all subjects before the lead foot touched the ground. The interval from the top position to ball release was 0.242 ± 0.0438 [s] (n = 11). The subjects were divided into two groups by the type of posture at the instant of the top position, as follows: internal rotation group (n = 5), 11.8 ± 6.08 degrees, and external rotation group (n = 6), 38.1 ± 19.97. Other kinematics parameters at the top position were adduction of the shoulder at 74.2 ± 19.84 degrees, horizontal adduction of the shoulder at 37.3 ± 14.10 degrees, and extension of the elbow at 92.1 ± 21.63 degrees. The timing and posture of the estimated top position were almost the same as those of the conventional top position.From the top position to lead foot contact on the pitching sequence, there were three patterns of elbow leading. The three patterns did not depend upon experience. We interpreted them as individual variations.