Wong WJ1, Lai DM2, Hsu WL1,3
1National Taiwan University, School and Graduate Institute of Physical Therapy, College of Medicine, Taipei City, Taiwan, 2National Taiwan University Hospital, Department of Surgery, Division of Neurosurgery, Taipei, Taiwan, 3National Taiwan University Hospital, Physical Therapy Center, Taipei, Taiwan
Background: Patients with degenerative lumbar spine diseases may suffer from low back pain (LBP), functional limitation and balance stability impairment. Recent studies have reported the immediate effects of lumbar surgery for improvement in pain and functional performance for patients when conservative treatments are not effective. However, the recovery in balance stability after lumbar surgery is still unclear.
Purpose: To determine the changes in balance stability during quiet standing in patients with degenerative lumbar spine diseases after lumbar surgery and compared them with healthy controls.
Methods: Seventy patients with degenerative lumbar spine diseases who received lumbar surgery (LBP group) and 30 healthy controls were recruited. All participants were instructed standing in natural stance (with feet shoulder-width apart) and in Romberg stance (with feet together) with their eyes closed on a force platform for 30 seconds, respectively. The assessments were performed in LBP group at four phases: preoperatively, 3-month, 6-month, and 12-month postoperatively; only one-time assessment was performed in controls. Balance stability was assessed using the anteroposterior, mediolateral direction, and resultant of center of pressure (COP) variables, including sway area, range, mean velocity, root mean square distance, and total excursions. LBP group was then divided into two subgroups according to the improvement of COP velocity at the 3-month postoperatively when compared to those preoperatively: LBP group with improvement (LBP group 1) and without improvement (LBP group 2). Other clinical assessments, including Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were performed in LBP group. As the data were not normally distributed, the time differences in LBP group were analyzed by Wilcoxon signed-rank test with a Bonferroni correction (p=0.008). The differences between two groups were analyzed by Mann-Whitney U test with a significance level set at p 0.05.
Results: In LBP group 1, COP variables during natural stance and Romberg stance were significantly decreased at 3-month, 6-month and 12-month postoperatively compared to preoperatively (p 0.008). For the group comparison, COP variables of LBP group 1 during natural stance and Romberg stance were significantly increased at preoperatively, 6-month and 12-month postoperatively compared to controls (p 0.05). In LBP group 2, the COP variables during natural stance were significantly increased at 12-month postoperatively compared to preoperatively (p 0.008). For the group comparison, COP variables of LBP group 2 during natural stance and Romberg stance were significantly increased in all time points compared to controls (p 0.05). The VAS score, ODI score, and RMDQ score of the LBP group significantly improved after surgery (p 0.001).
Conclusion(s): Balance stability of patients who improved since 3-month postoperatively may also show improvement throughout 12-month postoperatively. Therefore, three-month postoperatively may be a predictor for recovery in balance stability after lumbar surgery. However, both patients with and without improvement at 3-month postoperatively were still less stable than healthy controls at 12-month postoperatively. Therefore, the patients need postoperative balance training for optimizing the balance stability and reducing the risk of falling. Future studies relevant to the underlying balance stability mechanism after lumbar surgery should be investigated.
Implications: Balance assessments and training should be included in postoperative rehabilitation.
Keywords: Degenerative lumbar spine diseases, Lumbar surgery, Balance stability
Funding acknowledgements: Supported by the Ministry of Science and Technology (105-2628-E-002-006-MY3), and National Taiwan University (NTU-CDP-107L7733) awarded to Dr. Wei-Li Hsu.
Purpose: To determine the changes in balance stability during quiet standing in patients with degenerative lumbar spine diseases after lumbar surgery and compared them with healthy controls.
Methods: Seventy patients with degenerative lumbar spine diseases who received lumbar surgery (LBP group) and 30 healthy controls were recruited. All participants were instructed standing in natural stance (with feet shoulder-width apart) and in Romberg stance (with feet together) with their eyes closed on a force platform for 30 seconds, respectively. The assessments were performed in LBP group at four phases: preoperatively, 3-month, 6-month, and 12-month postoperatively; only one-time assessment was performed in controls. Balance stability was assessed using the anteroposterior, mediolateral direction, and resultant of center of pressure (COP) variables, including sway area, range, mean velocity, root mean square distance, and total excursions. LBP group was then divided into two subgroups according to the improvement of COP velocity at the 3-month postoperatively when compared to those preoperatively: LBP group with improvement (LBP group 1) and without improvement (LBP group 2). Other clinical assessments, including Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were performed in LBP group. As the data were not normally distributed, the time differences in LBP group were analyzed by Wilcoxon signed-rank test with a Bonferroni correction (p=0.008). The differences between two groups were analyzed by Mann-Whitney U test with a significance level set at p 0.05.
Results: In LBP group 1, COP variables during natural stance and Romberg stance were significantly decreased at 3-month, 6-month and 12-month postoperatively compared to preoperatively (p 0.008). For the group comparison, COP variables of LBP group 1 during natural stance and Romberg stance were significantly increased at preoperatively, 6-month and 12-month postoperatively compared to controls (p 0.05). In LBP group 2, the COP variables during natural stance were significantly increased at 12-month postoperatively compared to preoperatively (p 0.008). For the group comparison, COP variables of LBP group 2 during natural stance and Romberg stance were significantly increased in all time points compared to controls (p 0.05). The VAS score, ODI score, and RMDQ score of the LBP group significantly improved after surgery (p 0.001).
Conclusion(s): Balance stability of patients who improved since 3-month postoperatively may also show improvement throughout 12-month postoperatively. Therefore, three-month postoperatively may be a predictor for recovery in balance stability after lumbar surgery. However, both patients with and without improvement at 3-month postoperatively were still less stable than healthy controls at 12-month postoperatively. Therefore, the patients need postoperative balance training for optimizing the balance stability and reducing the risk of falling. Future studies relevant to the underlying balance stability mechanism after lumbar surgery should be investigated.
Implications: Balance assessments and training should be included in postoperative rehabilitation.
Keywords: Degenerative lumbar spine diseases, Lumbar surgery, Balance stability
Funding acknowledgements: Supported by the Ministry of Science and Technology (105-2628-E-002-006-MY3), and National Taiwan University (NTU-CDP-107L7733) awarded to Dr. Wei-Li Hsu.
Topic: Human movement analysis; Musculoskeletal: spine; Disability & rehabilitation
Ethics approval required: Yes
Institution: National Taiwan University Hospital
Ethics committee: National Taiwan University Hospital Research Ethics Committee
Ethics number: 201112117RIC
All authors, affiliations and abstracts have been published as submitted.
