Biomechanical Analysis of Elbow End-Feel Test in Supination, Pronation, Neutral Positions

• Main Authors: Chih-Chan Wu, 吳志展
• Other Authors: Ar-Tyan Hsu
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/71103226430778669200

碩士 === 國立成功大學 === 物理治療研究所 === 96 === Background and Purpose. End-feel test is a conventional practice for the therapist to screen lesions and guide interventions. The popular practice does not prove its reliability and validity. Conversely, it is a questionable diagnosis tool reported by the previous studies. Lack of biomechanical study misleads the professional judgments on the pathologies and even therapeutic effect. To reveal the true picture of end-feel test I examined the angle displacement and joint torque curve of the end-feel test to portray the profile of two normal type end-feels on the elbow joint which are soft-tissue approximation in flexion and bone-to-bone in extension first proposed by Dr. Cyriax. In general although the forearm rotation doesn’t change the normal end-feels in the elbow joint, the difference of angle-torque relationship in different forearm positions was also examined connect with elbow structures. Method 10 male and 13 female healthy subjects were recruited to this study. Kine-matics of the elbow motion was recorded by electrical magnetic system (Fastrak, Polhe-mus), and my exertion was measured by a loadcell (MLP SERIES LOAD CELL, Transducer Techniques Inc.) installed on the customized wrist splint. Flexion and extension end-feel tests in three forearm positions (supination/ pronation/ neutral) were employed in this study. The joint torque regarded as the resistance of end-feel perceived by me and was adjusted by gravity compensates. The angle-torque curve was then divided into four parts which are the neutral zone (NZ), first section of the toe region (T1), second section of the toe region (T2), and terminal linear region (TL) as material testing. Four slopes of the curve were derived by regression method. Other parameters are the angle displacement in the toe region (AT), and from the beginning of the toe region to certain torque, such as 4 Nm (A4), 8 Nm (A8). The angle displacements are the indicators of how long the resis-tance development. Repeat measure MANOVA was used to observe the difference from types of end-feels, forearm positions, gender, and elbow hyperextension or not. Results. The flexion end-feel is larger than extension in Neutral Zone slope (p=0.019), angle displacement in the toe region (p=0.002), angle displacement from the beginning of the toe region to 4 Nm (p=0.008), and to 8 Nm (p=0.017). The forearm positions only took action on the second section of the toe region slope. In neutral position the second section of the toe region slope is the largest (p=0.016 for pronation, 0.029 for supination). The male subject has larger Neutral Zone slope than female (p=0.019). Conclusion. The forearm positions presented the difference in the toe region of the angle-torque curve slope but this distinction is rather vague for people to detect. What clinicians can distinguish is the angle displacements from initial resistance rising to certain resistance, but the distinguishable feeling cannot be directed to specific tissues, as Dr. Cyriax proposed. However, The angle-torque curve is an honest profile of end-feel and the distinguishable characteristic of the angle-torque curve is still feasible to create the end-feel diagnosis model in the future.