Biomedical subjects

Simo Taimela

Publications and source records attributed to Simo Taimela.

8 recordsLinked to original sources

PubMed2005

Determinants of lumbar artery occlusion among patients with sciatica: a three-year follow-up with magnetic resonance angiography.

We showed previously that chronic Chlamydia pneumoniae infection increases the risk of lumbar artery occlusion. We did not evaluate, however, the effect of other risk factors for cardiovascular diseases in combination with this chronic infection. The purpose of this study was to investigate the combined effect of chronic C. pneumoniae infection and other known determinants of artery occlusion in a population of sciatica patients. Two-dimensional time-of-flight magnetic resonance angiography (MRA) was used to evaluate lumbar arteries at baseline and three years. The arteries on both sides (L1-L4) were evaluated visually and scored as normal, narrowed or occluded. Logistic regression analysis was performed separately for baseline total arterial stenosis and each L1-L4 segmental artery pair, and for incident new stenosis during the follow-up period. The determinants analyzed included age, body mass index (BMI, kg/m(2)), education, gender, and smoking, in addition to presence of chronic C. pneumoniae infection. MRA was obtained at baseline for 147 patients and at 3 years for 134 patients. Sixty-four (47.8%) of 134 patients had new arterial stenosis. Total incidence of new arterial stenosis was distributed quite evenly between the individual segmental levels, varying from 12.7 to 18.6%. BMI was the only predictor of new arterial stenosis (odds ratio (OR) 1.13). A reasonable logistic model could be established only for baseline L4 and total arterial scores. At L4, education was a protective factor (OR 0.07), whereas age (OR for the oldest age group 6.7) and BMI (OR 1.17) were associated with increased risk of occlusion. For total arterial score, chronic C. pneumoniae infection was an independent determinant of arterial occlusion, increasing the risk to almost eightfold. Additionally, BMI (OR 1.16), and age (for the oldest age group OR 11.4) were significant determinants for stenosis. Smoking was not statistically significant. As chronic C. pneumoniae infection was an independent determinant of lumbar artery occlusion, treatments of this chronic infection may have an impact on lumbar diseases. The importance of BMI for new arterial stenosis suggests that weight reduction may also have a beneficial effect in lumbar artery disease.

Adult↗

PubMed2005

Back extensor muscle oxygenation and fatigability in healthy subjects and low back pain patients during dynamic back extension exertion.

The purpose of this study was to assess if chronic low back pain patients have impaired paraspinal muscle O2 turnover and endurance capacity as compared to healthy control subjects during dynamic exercise. Middle-aged healthy male subjects (n = 12, control) and male patients with chronic low back pain (n = 17, CLBP) participated in the study. L4–L5 level paraspinal muscle fatigue was objectively assessed during earlier validated 90 s dynamic back endurance test (spectral EMG, MPFslope). Also EMG amplitude (EMGamplitude) and initial MPF (MPFinitial) were assessed from the initial 5 s of the endurance contraction. Simultaneously near infrared spectroscopy (NIRS) was used for quantitative measurement of local L4–L5 paraspinal muscle O2 consumption. Subcutaneous tissue thickness (ATT) was measured from the EMG and NIRS recording sites. The results indicated that control and CLBP groups were compatible as regarding anthropometric variables, paraspinal muscle activation levels (EMGamplitude), initial MPF (MPFinitial) and ATT. When the ATT was used as a covariate in the ANOVA analysis, CLBP group did not show significantly greater paraspinal muscle fatigability (right MPFslope – 12.2 ± 10.7%/min, left right MPFslope – 12.6 ± 13.3%/min) or O2 consumption (right NIRSslope – 52.8 ± 79.6 μM/l/s) as compared to healthy controls (right MPFslope – 11.9 ± 7.6%/min, left MPFslope – 12.7 ± 8.6%/min, right NIRSslope – 53.7 ± 95.2 μM/l/s). As a conclusion, these CLBP male patients did not show any impaired rate of paraspinal muscle oxygen consumption or excessive paraspinal muscle fatigability during dynamic exercise as compared with healthy controls. Subcutaneous tissue thickness has a strong influence on the NIRS and EMG amplitude measurements and, if unchecked, it could result in the false interpretation of the results.

Journal Article↗

PubMed2003

Lumbar paraspinal muscle function, perception of lumbar position, and postural control in disc herniation-related back pain.

STUDY DESIGN: A follow-up study evaluating postural control, lumbar movement perception, and paraspinal muscle reflexes in disc herniation-related chronic low back pain (LBP) before and after discectomy. OBJECTIVES: To assess the effect of discectomy on postural control, lumbar perception, and reflex activation of paraspinal muscles during sudden upper limb loading. SUMMARY OF BACKGROUND DATA: Impaired muscle function, postural control, and lumbar proprioception have been observed in LBP. However, they have not been studied in sciatica patients after surgery. METHODS: The study included 20 patients selected for an operation for chronic LBP caused by disc herniation and 15 controls without chronic LBP. The paraspinal muscle responses for upper limb loading during unexpected and expected conditions were measured by surface electromyography. The ability to sense lumbar rotation was assessed in a previously validated motorized trunk rotation unit in the seated position. The postural control was measured with a vertical force platform. Pain, disability, and depression scores were recorded. RESULTS: Patients had poorer lumbar perception (P = 0.012) and postural control (P < 0.05) than did healthy controls. The postural control remained unchanged, but lumbar perception (P = 0.054) and the lumbar feed-forward control (P = 0.043) improved after the surgery. CONCLUSIONS: The results demonstrate impaired lumbar proprioception and postural control in sciatica patients. During short-term follow-up after operative treatment, postural control does not seem to change, but impaired lumbar proprioception and feed-forward control of paraspinal muscles seem to recover.

Chronic Disease↗

PubMed2003

Paraspinal muscle denervation, paradoxically good lumbar endurance, and an abnormal flexion-extension cycle in lumbar spinal stenosis.

STUDY DESIGN: A descriptive study was conducted to investigate the paraspinal muscle function in patients with lumbar spinal stenosis. OBJECTIVE: To evaluate paraspinal muscle innervation and endurance in lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: Abnormal lumbar paraspinal muscle function is associated with chronic low back pain. Abnormal neurophysiologic findings of the lower limbs often are observed in lumbar spinal stenosis, and abnormal lumbar function also can be expected. However, paraspinal muscle function and innervation have not been studied in lumbar spinal stenosis. METHODS: The study evaluated 25 patients with clinically and radiologically diagnosed lumbar spinal stenosis. Electromyography of the paraspinal muscles was performed from L3 to S1 bilaterally using a concentric needle. At least 20 insertions were analyzed from each muscle. The aim of the examination was to detect abnormal spontaneous activity associated with axonal damage (fibrillation potentials, positive sharp waves, and complex repetitive discharges). Paraspinal muscle activity during trunk flexion-extension movement and muscle endurance during the dynamic isoinertial back endurance test were assessed by surface electromyography. Muscle fatigue was calculated using mean power frequency analysis. RESULTS: Abnormal findings in needle electromyography of the paraspinal muscles were observed in 18 of the 22 (81.8%) examined patients. Abnormal flexion-extension activation of the paraspinal muscles was observed in all the examined patients. The change in mean power frequency was significantly smaller than in previously evaluated healthy subjects and patients with nonspecific chronic low back pain (P < 0.001) who were not experiencing symptoms of lumbar spinal stenosis. Paraspinal muscle fatigability was not associated with the denervation of the muscles. CONCLUSIONS Denervation and abnormal activation of lumbar paraspinal muscles are frequent findings in patients with lumbar spinal stenosis who have not undergone surgery. The paraspinal muscle endurance of the patients was unexpectedly good.

Adult↗

PubMed2002

Paraspinal muscle responses during sudden upper limb loading.

The paraspinal muscle responses for unexpected and expected upper limb loading were investigated by surface EMG of 20 healthy volunteers. The simultaneous trunk and hand accelerations with paraspinal, biceps brachii and soleus muscles EMG were measured in four subjects. A short-latency response of approximately 50 ms was observed in paraspinal muscles. The latency was approximately 3 ms shorter (P = 0.017) during "expected" trials on average and the latency shortened during the first three expected trials (P = 0.02). Anticipation also decreased the magnitude of the response (P < 0.05). Trunk movement initiated approximately 35 ms and approximately 50 ms after the impact of the load at T6 and T12 levels, respectively. In conclusion, visual expectation shortens the latency and decreases the magnitude of the paraspinal muscle response to sudden upper limb loading. Also, the trial repetition has an effect on reflex latency if visual information is available. These results indicate that anticipation modulates the reflex control of paraspinal muscles, which may be significant in understanding spinal function.

Acceleration↗

PubMed2002

Impaired lumbar movement perception in association with postural stability and motor- and somatosensory-evoked potentials in lumbar spinal stenosis.

STUDY DESIGN: A descriptive study of the associations between different neurophysiologic findings in patients with lumbar spinal stenosis. OBJECTIVES: To evaluate the ability to sense a change in lumbar position and the associations between lumbar movement perception, postural stability, and motor-evoked potentials and somatosensory-evoked potentials. SUMMARY OF BACKGROUND DATA: Patients with low back pain have impaired postural control and impaired lumbar proprioception. Altered motor-evoked potentials and somatosensory-evoked potentials have been often observed in lumbar spinal stenosis. METHODS: The study included 26 patients with clinically and radiologically diagnosed lumbar spinal stenosis. Their ability to sense lumbar rotation was assessed in a previously validated motorized trunk rotation unit in the seated position. The abilities to indicate the movement direction and the movement magnitude were used as indexes of the ability to sense the lumbar rotatory movement. The postural stability was measured with a vertical force platform. The motor-evoked potentials were elicited by transcranial and lumbar stimulation and recorded from anterior tibialis muscles. The somatosensory-evoked potentials were elicited by transcutaneous electrical stimulation of the tibial nerve at the ankle. RESULTS: Twenty patients (76.9%; P = 0.006) reported the wrong movement direction. Furthermore, the patients consistently localized the movement sensation in their shoulders instead of the lumbar region. The altered motor-evoked potentials and somatosensory-evoked potentials were observed in 11 and 16 patients, respectively. Abnormal motor-evoked potentials had inconsistent associations with impaired movement perception and postural stability and abnormal somatosensory-evoked potentials had no associations with other findings. CONCLUSIONS: Many patients with lumbar spinal stenosis have difficulties in sensing the lumbar rotational movement, which may indicate impaired proprioceptive abilities. Abnormal motor-evoked potentials and somatosensory-evoked potentials are also frequent in lumbar spinal stenosis but do not necessarily occur in the same patients as the abnormal ability to sense trunk movement. These new findings add to our understanding of the pathophysiology of lumbar spinal stenosis.

Evoked Potentials, Motor↗

PubMed2002

A randomized controlled trial of rehabilitation after hospitalization in frail older women: effects on strength, balance and mobility.

When frail older people become acutely ill, they are at increased risk of further functional deterioration and rehabilitation is needed to restore functioning. The effects of an out-patient multicomponent training program including strength training after hospitalization were studied in a randomized controlled trial. Sixty-eight women (mean age 83.0 +/- 3.9 years) who were hospitalized due to an acute illness and were mobility impaired at admission were randomized into training (N = 34) and home exercise (N = 34) groups. Maximal voluntary isometric strength of knee extension and hip abduction, dynamic balance, and maximal walking speed were measured before and after the 10-week training period, and 3 and 9 months after the end of the intervention. After the intervention, significant improvements were observed in the training group compared to the home exercise group in the maximal voluntary isometric knee extension strength (20.8% vs. 5.1%, P= 0.009), balance scale (+ 4.4 points vs. -1.3 points, P= 0.001) and walking speed (+ 0.12 m s-1 vs. -0.05 m s-1, P= 0.022). Effects on knee extension and hip abduction strength, balance and walking speed were observed 3 months later, and some effects on hip abduction strength (9.0% vs. -11.8%, P= 0.004) and mobility were still apparent even 9 months after the intervention.

Aged↗

PubMed2002

Does good trunk extensor performance protect against back-related work disability?

In this cohort study, dynamic trunk extensor performance was studied as a predictor of permanent work disability due to back disorders. As part of the comprehensive Mini-Finland Health Survey in 1978-80, the back muscle performance of 535 persons (267 men, 268 women) was measured using standardized repetitive arch-up and sit-up tests. At baseline, the participants were between 30 and 64 years of age. Retirements were followed for 12 years on average. During the follow-up, 56 subjects developed permanent work disability; 15 of these cases were back-related. Good dynamic trunk extensor performance was predictive of a decreased incidence of work disability due to chronic back disorders but not work disability due to other diseases. The risk of back-related work disability in the three highest quartiles in relation to the lowest quartile of dynamic trunk extension capacity was 0.28 (95% confidence interval, 0.09-0.94). Our study suggests that good dynamic trunk extension performance may protect against back-related permanent work disability.

Adult↗