下背痛病人接受脊椎手術後在前伸動作下之肌肉與功能性表現情形

Abstract

研究設計. 前瞻型與縱向型研究 研究目的. 本篇主旨即在檢驗接受腰椎融合手術的下背痛病人，執行最大前伸動作時軀幹與下肢肌肉的代償活化現象。我們收集了病人在術前一天與術後一個月的表現，比較其術前與術後的差異。 研究背景摘要. 腰椎融合手術是臨床解決下背痛病患症狀最有效率的方法，然而，過去的流行病學研究卻證實，患者在腰椎融合術後仍有相當高的再次手術機率。脊椎椎旁多裂肌由於直接位於手術侵入位置，次發性的腫脹、萎縮及脂肪細胞滲入都可能引發疼痛與無力，過去的文獻指出，椎旁肌在腰椎融合手術中的受傷風險極高，但探討椎旁多裂肌在術後的改變與其對於功能性活動影響的研究至今卻仍不足。病人術後在執行功能性活動是否會在其他軀幹與下肢肌肉產生代償效應，是本研究所關切的。 研究方法. 十五位下背痛病人（平均年齡53.17±16.01歲）與年齡、性別相符的健康成人受試者（平均年齡59.35±13.04歲）被納入本次實驗。肌電感應電極安置在受試者的軀幹與雙側下肢之16條肌肉，包含前側腹直肌、股直肌、脛前肌，背側包含豎背肌、腰部多裂肌、臀大肌、股二頭肌與內側腓腸肌。受試者會在自選速度下執行3次最大距離的前伸測試，並在最大的前伸距離動作下停留三秒。受試者的前伸距離會以其足部長度做為標準化依據，並利用Matlab軟體計算與分析在前伸動作中的肌肉活性均平方根、主成分分析。標準化後的前伸距離在手術前後的差異利用配對t測試檢定、病人組與正常組間使用獨立t測試檢定。肌肉活性方面，則利用雙因子多重變異量分析，雙因子分別為族群（正常組 vs. 病人組術前/正常組 vs. 病人組術後）及時期（前伸期 vs. 三秒維持期）。顯著程度則設定在p值小於0.05。 研究結果. 經統計分析後發現，病人組無論術前或術後，執行最大前伸的距離均顯著較正常人來的短，但病人組本身在術前術後卻沒有差異。病人術後的腰部多裂肌與內側腓腸肌活動有下降的趨勢，豎背肌與內側腓腸肌活動則在術後較正常人的活動量來的低。時期因子則在背部與下肢肌肉有顯著的變化。 結論. 下背痛病人在接受脊椎微創手術一個月之後，其神經肌肉控制能力尚未完全恢復，使得在執行伸取動作時，背部肌肉與踝部產生代償性肌肉活動下降。臨床工作者在術後需長期追蹤並評估脊椎手術術後之病患，前伸測試是能夠使用的有效評估工具之一。

Study Design. Prospective and longitudinal analysis Objective. The purpose of current study was to identify the compensatory muscle firing pattern in the trunk and the lower extremities during the maximum forward reach task in patients with LBP at one-month post lumbar spinal fusion surgery. Summary of Background Data. Lumbar spinal fusion surgery is thought to decrease the symptoms of low back pain (LBP) patient efficiently in orthopedic clinic. However, mounting evidence shows high re-operation rate after surgery. Swelling, atrophy or fat infiltration of the multifidus muscles at the surgery site can cause weakness and pain. High probability of multifidus muscle damage has been reported during operation procedure, but only few studies have addressed the changes in muscle and functional performance after lumbar spinal fusion surgery. We are interested in the compensatory muscle activation pattern in the trunk and the lower limb muscles during functional activity. Methods. Fifteen patients with LBP (mean age 53.17±16.01 years old) at pre/post operation and 15 age- and gender- matched healthy participants (mean age 59.35±13.04 years old) were recruited. Sixteen electromyography (EMG) sensors were placed on the rectus abdominis (REA), rectus femoris (REF), tibia anterior (TIA), erector spinae (ERE), multifidus (MUL), gluteus maximus (GM), medial gastrocnemius (MEG) and biceps femoris (BIF) muscles bilaterally. Participants were asked to perform a maximum forward reach task with their self-selected speed and holding for 3 seconds at the terminal position. The reaching distance was normalized by the individual foot length. The root mean square (RMS) of the EMGs were computed in Matlab and analyzed. The differences in normalized reaching distance were examined by paired t-test between patients at pre/post operation (Pre-op/Post-op) and by independent t-test between patients at each time point and the control group (Control). The EMGs activity difference between the control group and patients at Pre-op/Post-op were examined by two way repeated measure using analysis of variance. The two factors were Group (Control vs. Pre-op / Control vs. Post-op) and Phase (reaching phase vs. 3-second holding phase). The significant level was set at p value < 0.05. Results. The normalized reaching distance was shorter in patients at Pre-op (79.87±26.07%) and Post-op (71.64±27.69%) compared to the controls (102.57±17.03%). No difference in normalized reaching distance was found in the patient group between Pre-op and Post-op. The muscle activities of ERE and MEG muscles in the patient group at Post-op were lower than the controls. The MUL and MEG muscles activities in the patient group at Post-op were both lower than at Pre-op. Significant phase effect was found in most of the back and lower limb muscles. Conclusions. The neuromuscular control had not fully recovered to the normal state at one-month after lumbar spinal surgery, so the compensatory muscle firing pattern appeared around the lumbar and ankle joint during functional activity, such as forward reaching. Clinician should evaluate the patient after spine surgery at different time points. Forward reach task could be one of the most efficient tools to use.