Pain Avoidance Mechanism in Patients with Lumbar Instability ─The Relationship Between Clinical Features and Lumbar Motion

• Main Authors: Wen-Paw Lin, 林文寶
• Other Authors: Wen-Ling Chen
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/r24m77

碩士 === 國立成功大學 === 物理治療研究所 === 92 === Background：Lumbar instability was frequently cited as an important cause of low back pain. Previous studies mainly focused on the subjective description of clinical symptoms.Little information with respect to motion analysis or symptoms during movement was addressed. In addition, the relationship between clinical features and motor control strategies in lumbar instability has not been thoroughly explored. Lumbar instability was therefore classified as non-specific low back pain, leading to ambiguous diagnosis and inefficient treatment. Purpose：Ultrasound-based motion analysis system was used in patients lumbar instability to clarify their strategies of lumbar control and its relation toclinical features. In addition, dynamic flexion-extension radiography was used to analyze to illustrate the compensatory mechanism of lumbar motion. Method：70 patients diagnosed as induced spondylolisthesis or degenerative spondylolisthesis were recruited to undergo flexion-extension radiographs. The information with respect to the history ofback pain, pain intensity, and Revised Oswestry Disability Index (RODI) was also taken.Besides, 35 volunteers from these subjects were arranged to attend straight leg rasing (SLR) tests and motion analyisis during trunk forward bending. Result：In view of the relationship between lumbar control and clinical features, subjects with poorer motor function exhibited significantly shorter duration in early phase of extension movements,and significantly longer duration in late phase of extension movements. The lumbopelvic ratio (LPR) were also found to be significantly lower with increasing RODI (r=-0.41, p<0.05).Subjects with larger dynamic translation (DT) at L45 exhibited significantly more dysfunction.However, significantly lower DT at L45 was also found in patients with longer history of back pain. Most of all, while significantly positive correlation was found between adjacent intervetebral segments both for upper and lower lumbar spine (DT at L12versus L23, r=0.42, p<0.01; DT at L45 versus L5S1, r=0.35, p<0.01), significantly negative correlation was found between DT at upper lumbar and that at lower lumbar spine (DT atL23 versus L45,r=-0.27, p<0.05). The compensatory phenomenon was also supported by significantly negative correlation found between DT at L23 and the intensity of back pain(r=-0.41, p<0.05). Finally, the index of instability tendency (Iit), proposed in the presentstudy, was found to be significantly lower in patients with degenerative spondylolisthesis to compare with that in patients with induced spondylolisthesis (t=-2.3, p<0.05).Discussion and Conclusion：The results in present study not only proposed a quantitative system for evaluating the motor control strategies to patients with lumbar instability, butalso provided better understanding in the relationship between motor control and clinical features.Furthermore, patients with larger DT at L45 exhibited significantly poorer back function as well as significantly smaller DT at L23, clearly demonstrated a pain-avoidance phenomenon in presence of lumbar instability. The results also provided strong evidence to illustrate the compensatory mechanism found between upper lumbar and lower lumbar spine, and further supported the treatment concepts suggested in chiropractice to reduce excessive motion in compensated joints by correcting the underlying hypomobile segment. Finally, the present study proposed a new parameter, namely lumbopelvic ratio (LPR), that can be used to successfully reflect the effect of back dysfunction and limited SLR on theability of trunk control in patients with lumbar instability. In addition, Iit can be used to determine the tendency of instability facilitation so as to early detect degenerative spondylolisthesis.In aword, current study has shown its clinical significance in assisting differential diagnosis for degenerative spondylolisthesis and clarifying the related clinicalcharacteristics. Side evidence was also provided for proving compensatory mechanism ofspinal control that can be used in the applications of treating spinal instability