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Biomedical subjects

H Vanharanta

Publications and source records attributed to H Vanharanta.

At least 19 recordsLinked to original sources
PubMed1992

Effect of Gz forces and head movements on cervical erector spinae muscle strain.

A portable surface-integrated EMG (IEMG) device was used to investigate the strain caused by low and high Gz forces and head movements on the cervical erector spinae muscles during flight missions. The obtained IEMG activities were normalized by comparing them with activities representing maximal voluntary contraction (MVC) of the cervical erector spinae muscles in each subject. The muscular strain increased with increasing Gz forces and head movements. Under +7.0 Gz the mean muscular strain was 5.9-fold compared with +1.0 Gz and was 37.9% of the MVC. In some individuals, the muscular tolerance (100% of the MVC) was ipsilaterally reached already under +4.0 Gz with concomitant movements and twisted positions of the head. Pilots are susceptible to acute neck injury when the protection afforded by their neck muscles is insufficient.

Adult↗
PubMed1991

Ultrasound diagnosis of lumbar disc degeneration. Comparison with computed tomography/discography.

Transabdominal ultrasound (US) imaging was compared with computed tomography (CT)/discography in order to assess whether the former could be used for screening discs to be examined by CT/discography, or could be used to replace CT/discography. A total of 56 discs in 29 patients was examined by both methods. The US findings were classified as local or generalized disc lesions, and the CT/discography findings according to the Dallas Discogram Description. The sensitivity of US for recognizing a discographically painful and deteriorated disc was 0.95, and its specificity was 0.38. Correspondingly, the predictive value of a positive US finding was 1.53, and that of a negative finding was 0.13. US is considered suitable for screening discs prior to CT/discography.

Adult↗
PubMed1991

Effects and follow-up of a multimodal treatment program including intensive physical training for low back pain patients.

The results of a comprehensive 4-week treatment program including intensive physical training were evaluated in 65 chronic low back pain patients. Marked increases in measures of spinal mobility, trunk muscle strength and lifting capacity were found during the treatment, but no average increase in pain ratings. At 3-week and 12-month follow-ups a statistically significant decrease in subjective disability and pain was found, but the percentage of patients who were working was unchanged. This points to a need for more work-oriented rehabilitation efforts in the treatment.

Adult↗
PubMed1989

Different effects of mechanical vibration on bone ingrowth into porous hydroxyapatite and fracture healing in a rabbit model.

The effects of mechanical vibration on bone ingrowth into porous hydroxyapatite implants and fracture healing were examined radiographically, histomorphometrically, and biomechanically in a rabbit model. Fifty-three female NZW rabbits were used in this study. These rabbits were divided into four separate studies to assess the effects of 20 and 60 min of vibration/day in both implant and osteotomy models as compared with the respective non-vibrated controls. For the implant model, coral hydroxyapatite goniopora rods were implanted bilaterally into tibiae and for the osteotomy model, bilateral fibulae were osteotomized. A resonant frequency of 25 Hz mechanical vibration was used. After periods of 2, 3, 4, and 6 weeks of vibration, the rabbits were killed and examined. For the implant model, there was no significant difference between control, 20, or 60 min of vibration/day with respect to the rate or amount of new bone ingrowth. For the fracture model, 60 min of vibration/day produced a significantly larger callus as compared with the non-vibrated controls (p less than 0.05), whereas 20 min of vibration/day did not. Although biomechanical testing demonstrated a general trend for increased strength in the vibrated animals, it failed to reach significance. These results suggest that the mechanical vibration used in the present study had a beneficial effect on callus volume, possibly due to the stimulation of secondary bone healing processes, but does not appear to promote bone ingrowth into a porous hydroxyapatite implant.

Animals↗
PubMed1989

Comparison of CT scan muscle measurements and isokinetic trunk strength in postoperative patients.

The present study compared the computed tomography (CT) scan muscle area/muscle density and isokinetic trunk strength of a group of spinal surgery patients (35 males and 11 females) 3 months postoperatively. Analyses showed trunk strength means to be below 50% of gender-specific "normal" values obtained by evaluating a normative sample. Extensor strength was more significantly affected than flexors. Single-cut CT scans performed at the time of isokinetic trunk strength assessment demonstrated psoas and erector spinae atrophy through a significant decrease in muscle density, with only a trend towards decreased cross-sectional area. Findings also indicated that there was a significant correlation between increased mechanical trunk strength performance and greater muscle density on CT scan. Strength was significantly lower for the male patients undergoing spinal fusion compared with those undergoing disc excision. However, no significant difference was found in strength measures between: males with high versus low pain level and working versus nonworking males at the time of evaluation.

Adult↗
PubMed1989

Pain provocation and disc deterioration by age. A CT/discography study in a low-back pain population.

The computed tomography (CT)/discograms and discographic pain provocation reports of 291 clinical patients, 790 discs (mean age, 38; range, 17-79) were collected. The CT/discograms were classified separating anular disruption and degeneration and recording the pain provoked during discography as no pain, dissimilar, similar, or exact reproduction of the patient's clinical pain. Nondegenerated discs usually were found to be painless, and deteriorated discs painful. The proportion of severely degenerated but painless discs increased with age, as did the discs producing dissimilar pain. This may help explain the poor correlation of low-back pain with radiographic degenerative changes reported in previous epidemiologic studies.

Adult↗
PubMed1989

[Back pain].

Explore the source record for details and available documents.

Back Pain↗
PubMed1988

A comparison of CT/discography, pain response and radiographic disc height.

CT/discograms of 107 low-back patients were classified by annular degeneration, annular disruption, and pain response. These parameters were compared with the heights of the corresponding discs. Disc height correlated significantly with degenerative annular changes. Comparison of the painless and exact reproduction groups at the L5-S1 level showed a significant increase in exact pain reproduction in narrow discs compared with normal discs. Discs demonstrating slight degenerative changes were often painful but narrowing was detected only when degeneration increased to moderate or severe levels. Some severely degenerated discs were painless and only part of the severe group was narrow. Measuring disc height is a poor method for detecting early, painful degeneration changes.

Back Pain↗
PubMed1988

Extraosseous spinal lesions mimicking disc disease.

To identify characteristics of patient presentation that would help distinguish extraosseous spinal tumors from the more common herniated disc, nine cases of intraspinal tumors were reviewed. These nine patients were identified in a group of 744 patients who presented with symptoms similar to disc herniation but failed to respond to conservative care and underwent spinal surgery. This study indicates that intraspinal tumor should be suspected in patients with the following characteristics: 1) painless neurological deficit; 2) night pain or pain which increases in the supine position; 3) pain disproportionate to that normally expected with lumbar disc disease; 4) no change in symptoms after successful surgery for herniated disc; 5) elevated spinal fluid protein; or 6) a teenager with symptoms of disc herniation. Myelography is an effective radiologic procedure for the diagnosis of spinal tumor but MRI should be equally effective if the procedure includes a scan of the conus as well as cauda equina.

Adolescent↗
PubMed1988

Disc deterioration in low-back syndromes. A prospective, multi-center CT/discography study.

Disc deterioration and pain provocation in different low-back pain syndromes was studied using computed tomography (CT) discography. Data were prospectively collected for 300 patients (816 discs). Patients were classified by their pre-discography diagnosis of disc herniation (DH), degenerated disc (DD), lumbar syndrome (LS), lumbar radicular syndrome (LRS), or other. The CT/discograms were classified by discographic pain response, the amount of degeneration and annular disruption. Eighty-two percent of DH patients, 80% of DD, 56% of LS, and 59% of LRS patients had both positive discographic pain provocation and moderate or severe disc deterioration. The study indicates that intradiscal pathology plays a major role in nonspecific low-back pain syndromes.

Back Pain↗
PubMed1987

Dallas discogram description. A new classification of CT/discography in low-back disorders.

A new classification method for CT/discography was developed. The Dallas discogram description (DDD) related five separate categories of information. Degeneration and annular disruption were regarded as separate phenomena. Additionally, provoked pain response, contrast volume, and miscellaneous information were recorded. Discogram findings of 59 patients with low-back and/or leg pain were graded according to the new method and compared with standard methods using routine anteroposterior and lateral discographic images. Findings from routine discography and CT/discography were graded and correlated with myelographic and plain computerized axial tomography (CAT) scans. This study demonstrated that the contrast-enhanced axial view provided by CT/discography served as a useful projection for demonstrating disc pathology. CT/discography analyzed according to DDD offered a more sensitive discriminator of disc degeneration from annular disruption (disc protrusion/leaking). This evaluation can be recommended as the procedure of choice when revision of spine surgery is considered or when there is an equivocal or negative correlation between clinical information and myelography or CAT scan.

Adult↗
PubMed1987

The relationship of pain provocation to lumbar disc deterioration as seen by CT/discography.

The CT/discographic findings from 225 discs in 91 low-back pain patients were compared to the pain provocation during the injection of contrast into the disc. The radiographic appearance of disc deterioration demonstrating disc degeneration and annular disruption of each disc was classified separately using a fourpoint scale: normal, slight, moderate, or severe. Pain reaction to the discogram at each level was recorded as follows: no pain, dissimilar pain, similar pain, or exact reproduction of the patient's clinical pain. This more precise analysis demonstrated a significant relationship between pain and deterioration of discs. The CT/discogram presents an axial view of the disc that allows a subgrouping of disc deterioration that can discriminate between peripheral deterioration (degeneration) and internal deterioration (disruption). The disruption supposedly occurs earlier and is more likely to be the source of exact pain reproduction.

Adult↗
PubMed1987

Occupation, work load and the size and shape of lumbar vertebral canals.

Measurements made from plain lumbar radiographs were used to compare the size and shape of the lumbar vertebral canals between various categories of occupation and work load among 77 men and 118 women with a history of low-back pain. The mean anteroposterior foraminal diameters proved to be wider in female farm workers than in other women, especially in the vertebra L3 (17.1 versus 15.4 mm). However, the men who did heavy manual work had smaller anteroposterior foraminal diameters than the men whose work involved less physical labor (difference at L5 9.4 versus 10.8 mm). Female farm workers were found to have shorter interarticular distances than females in other occupational groups. In the men who reported working in stooped postures or reported lifting and carrying heavy objects at work, the interarticular distances were wider than in men who had no such exposures.

Back Pain↗
PubMed1986

Herniated lumbar disc syndrome and vertebral canals.

Herniated lumbar disc or definite sciatica was diagnosed in 16 of 195 men and women who had reported a history of low-back pain in a health survey. Measurements related to the size and shape of the lumbar spinal canal were subsequently made from the survey radiographs and compared between various types of back syndromes. Age, body height, body mass index, occupation, and parity of women were controlled as potential confounders using analysis of covariance. Several dimensions of lumbar vertebral canals appeared more shallow in the subjects who had herniated disc or definite sciatica than in the other ones. In particular, the interarticular distance of the first sacral vertebra was found to be narrowed in the presence of sciatica, the difference of the adjusted distances to the other back pain category being in men 30.5 mm versus 35.1 mm (P = 0.02) and in women 23.8 mm versus 30.3 mm (P = 0.002), respectively.

Back Pain↗