Trunk Muscle Strength After Lumbar Spine Fusion: A 12-Month Follow-up.

OBJECTIVE: The aim of this study was to investigate changes in trunk muscle strength 12 months after lumbar spine fusion (LSF) compared to preoperative strength. METHODS: A total of 194 patients (mean±standard deviation [SD] age, 61±21 years) who underwent LSF participated in this prospective longitudinal study. Physical measurements of the participants were made before surgery and 12 months postoperatively. Isometric trunk extension and flexion strength was measured using a strain-gauge dynamometer in the standing position. Strength changes were calculated. Regression analysis was performed to explore which factors predicted strength levels at 12 months postoperatively. RESULTS: The preoperative mean±SD extension strength was 205±144 N, which increased to 258±142 N (p<0.001) at the 12-month follow-up. Flexion strength increased from 295±172 N to 364±164 N (p<0.001). The preoperative extension/flexion strength ratio was 0.75±0.38 and remained similar (0.73±0.26) at 12 months postoperatively (p=0.39). CONCLUSION: Although trunk muscle strength increased by 26% for extension and 23% for flexion at the 12-month postoperative follow-up, both values remained objectively low. In addition, flexion strength remained higher than extension strength, which indicates an imbalance between those muscle groups. Age, severe back pain, and low trunk muscle strength before surgery predicted low trunk muscle strength at 1 year after spinal fusion.

Effectiveness of postoperative home-exercise compared with usual care on kinesiophobia and physical activity in spondylolisthesis: A randomized controlled trial.

OBJECTIVE: To study the effectiveness of a 12-month exercise therapy on kinesiophobia and physical activity in patients with spondylolisthesis after lumbar spine fusion. DESIGN: Randomized controlled trial. SUBJECTS: Patients (n = 98) with spondylolisthesis who had undergone lumbar spine fusion. METHODS: All patients (mean age 59 years) had received lumbar spine fusion surgery and identical postoperative instructions. Three months postoperatively, they were randomized into an exercise group (n = 48) or usual care group (n = 50). The exercise group received 12-month progressive home-based training with regular booster sessions, and the usual care group a single session of physiotherapy instruction. Kinesiophobia was assessed with the Tampa Scale for Kinesiophobia (TSK) and physical activity by the International Physical Activity Questionnaire (IPAQ) preoperatively, 3 months after lumbar spine fusion, and at the end of the 12-month intervention. RESULTS: Before the intervention, the median (first quartile; third quartile) of TSK was 32.5 (29.0; 37.0) in the exercise group and 30.0 (25.8; 36.0) in the usual care group, changing to 30.0 (25; 36) in the exercise group and to 30.5 (24; 36.3) in the usual care group (between-group p = 0.17). IPAQ metabolic equivalent minutes per week increased from 1,863 (1,040; 3,042) to 3,190 (1,634; 6,485) in the exercise group and from 2,569 (1,501; 4,075) to 3,590 (1,634; 6,484) in the usual care group (between-group p = 0.92). CONCLUSION: Progressive 12-month home-exercise starting 3 months postoperatively was not superior to usual care in decreasing kinesiophobia or increasing physical activity in spondylolisthesis.

Neutral spine control exercises in rehabilitation after lumbar spine fusion.

Lumbar spine fusion (LSF) has been reported to change the biomechanics of the spine and therefore the rehabilitation after LSF is important. In this study, the effect of selected neutral spine control exercises on activation of trunk muscles after LSF was evaluated. Muscle activity was measured by surface electromyography of the rectus abdominis, external oblique, longissimus, and multifidus muscles during 6 exercises in 22 LSF patients (mean age = 59 years; age range = 25-84 years; 50% women). Muscle activity concurrent with trunk flexion and extension during maximal voluntary isometric contraction (MVIC) was used as a reference value. Pain during the effort was assessed with a visual analog scale (VAS). The highest activity in the rectus abdominis muscles was measured during bilateral shoulder extension (51% of MVIC), and in the external oblique, it occurred during unilateral shoulder horizontal adduction (48% of MVIC) and unilateral hip extension (46% of MVIC) exercises. The highest activation of the multifidus and longissimus muscles (60-104%) was measured during bilateral shoulder flexion and modified Roman chair exercises. The mean (SD) self-reported back pain VAS scores during exercises varied from 3 (7) to 16 (26). Neutral spine control exercises activate trunk muscles and cause minimal pain and are therefore feasible exercises for home-based training to improve muscle endurance and postural control after LSF. In addition, the level of muscle activity during bilateral shoulder flexion and modified Roman chair exercises was over 60% of MVIC, justifying their use in training for strength of the trunk extensor muscles.

The early changes in trunk muscle strength and disability following lumbar spine fusion.

PURPOSE: To analyze trunk muscle function pre- and postoperatively in patients undergoing lumbar spine fusion. Associations between changes in trunk muscle strength and disability were also studied. METHOD: A total of 114 patients undergoing lumbar spine fusion participated in the study. The flexion and extension strength of the trunk was measured preoperatively and 3 months after surgery using a strain-gauge dynamometer. Disability and pain during the past week was evaluated with the Oswestry disability index (ODI) and visual analog scale (VAS), respectively. RESULTS: Preoperative trunk extension and flexion strength levels were 319 N and 436 N in males, respectively, and 160 N and 214 N in females, respectively. In females 3 months postoperatively, the trunk extension strength increased by 39 N (p < 0.001) and flexion by 38N (p < 0.001), whereas it remained unchanged in males. The preoperative extension/flexion strength ratio was 0.79 in females and 0.76 in males. Three months postoperatively, the strength ratio decreased to 0.66 in males (p = 0.02). The mean ODI improved by 47% and back pain decreased by 65% (both p < 0.001). The changes in the ODI correlated with changes in trunk extension (r = -0.38) and flexion (r = -0.43) strength. CONCLUSIONS: Patients undergoing lumbar spine fusion had low trunk muscle strength and strength imbalance. Back fusion surgery leads to considerable relief of pain and disability, but patients still have low trunk extension and flexion strength levels 3 months postoperatively. Therefore, there is need for a proper progressive strength training protocols to normalize back function.

Randomized controlled trial of postoperative exercise rehabilitation program after lumbar spine fusion: study protocol.

BACKGROUND: Lumbar spine fusion (LSF) effectively decreases pain and disability in specific spinal disorders; however, the disability rate following surgery remains high. This, combined with the fact that in Western countries the number of LSF surgeries is increasing rapidly it is important to develop rehabilitation interventions that improve outcomes. METHODS/DESIGN: In the present RCT-study we aim to assess the effectiveness of a combined back-specific and aerobic exercise intervention for patients after LSF surgery. One hundred patients will be randomly allocated to a 12-month exercise intervention arm or a usual care arm. The exercise intervention will start three months after surgery and consist of six individual guidance sessions with a physiotherapist and a home-based exercise program. The primary outcome measures are low back pain, lower extremity pain, disability and quality of life. Secondary outcomes are back function and kinesiophobia. Exercise adherence will also be evaluated. The outcome measurements will be assessed at baseline (3 months postoperatively), at the end of the exercise intervention period (15 months postoperatively), and after a 1-year follow-up. DISCUSSION: The present RCT will evaluate the effectiveness of a long-term rehabilitation program after LSF. To our knowledge this will be the first study to evaluate a combination of strength training, control of the neutral lumbar spine position and aerobic training principles in rehabilitation after LSF. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00834015.

Core muscle activation during dynamic upper limb exercises in women.

Although several everyday functions and sporting activities demand controlled use of the abdominal and back muscles while working with the upper limbs, the activity of core muscles during dynamic upper limb exercises in the standing position has not been studied extensively. The purpose of this cross-sectional study was to examine abdominal and back muscle activity during dynamic upper limb exercises while standing and to evaluate whether dynamic exercises are appropriate for strengthening muscles. The activation of the rectus abdominis, obliquus externus abdominis, longissimus, and multifidus muscles during dynamic bilateral or unilateral shoulder exercises with or without fixation of the pelvis was measured in 20 healthy women using surface electromyography. Trunk muscle activation during isometric maximum contraction was used as a comparative reference. With bilateral shoulder extension and unilateral shoulder horizontal adduction, abdominal muscle activity was >60% of activity during reference exercises. With unilateral shoulder horizontal abduction and shoulder extension exercises, back muscle activity was >60% of the activity level reference exercise. Muscle activation levels were 35-64% lower during shoulder horizontal adduction and abduction without fixation compared with exercises with fixation. The results indicate that upper limb exercises performed in the standing position are effective for activating core muscles. Bilateral and unilateral shoulder extension and unilateral shoulder horizontal abduction and adduction with the pelvis fixed elicited the greatest activity of the core muscles.

Effect of isometric upper-extremity exercises on the activation of core stabilizing muscles.

OBJECTIVE: To evaluate whether isometric exercises for the upper extremities could sufficiently activate core stabilizing muscles to increase muscle strength. DESIGN: Cross-sectional study. SETTING: Department of physical medicine and rehabilitation at a Finnish hospital. PARTICIPANTS: Healthy adult women (N=20). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Peak isometric strength of the back and abdominal muscles was measured and relative loading in 5 test exercises was evaluated by surface electromyography. RESULTS: The rectus abdominis and obliquus externus abdominis were activated to the greatest degree in a bilateral shoulder extension exercise and the average surface electromyographic activity was 114% and 101% compared with the amplitude elicited during the maximal isometric trunk flexion exercise. Horizontal shoulder extension elicited the greatest activation of the longissimus and multifidus muscles. In this exercise, the activity levels of the left side multifidus and longissimus muscles were 84% and 69%, respectively, compared with the level of activity elicited during trunk extension. CONCLUSIONS: Of all the exercises studied, bilaterally performed isometric shoulder extension and unilaterally performed horizontal shoulder extension elicited the greatest levels of activation of the trunk musculature. Thus, it can be assumed that these exercises elicit sufficient levels of contraction of the trunk muscles for the development of their endurance and strength characteristics in rehabilitation.