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T Sihvonen

Publications and source records attributed to T Sihvonen.

12 recordsLinked to original sources
PubMed1991

Electric behavior of low back muscles during lumbar pelvic rhythm in low back pain patients and healthy controls.

UNLABELLED: The functioning of low back muscles of back pain patients during flexion and reextension has not been properly investigated. In this study, we analyzed rectified, averaged electric activity (RMS EMG) and corresponding raw intramuscular (IM) EMG from lumbar paraspinal muscles to quantify the activity level during simple bending cycles in 87 back pain patients compared to 25 able-bodied controls. THE RESULTS: All functional phases seen in raw IM EMG were also shown in surface RMS EMG. Surface RMS EMG pattern seems to yield more information from activity level than IM EMG pattern. The RMS EMG patterns of back pain patients differed from those of controls as follows: (1) There was clearly noticeable activity during standing in back pain patients. (2) There was only a partial decrease of EMG activity after flexion in back pain patients with current pain. (3) The ratio of mean reached at maximal activity level during extension and flexion was less in patients (1.8, SD = 0.5, p less than .001) than able-bodied controls (3.2, SD = 0.8). (4) Segmental differences were observed in IM EMG activities in patients having hypermobility in bending x-ray. (5) Large peak potentials occurred during movements in patients having segmental hypermobility. THE RESULTS indicate that averaged surface recording is a valuable tool in the investigation of dynamic spine functions in back pain patients.

Adult↗
PubMed1989

Neck-shoulder loading in wordprocessor use. Effect of learning, gymnastics and armsupports.

The loading of wordprocessor workers was followed over a four month period of a re-education course with the aid of electromyography of the trapezius and frontalis muscles in order to study the effect of learning. Working with the word processor increased the electrical activities in both muscles. The increase did not diminish with the learning of the work. On the contrary the electrical activity increased significantly in the frontalis muscle. Intervening gymnastics during work decreased the electrical activities. The screen (on/off) did not affect the activity. Most effective in lowering the myoelectrical activity in both muscles were the armsupports. A significant positive linear correlation was observed in the electrical activities of the trapezius and frontalis muscles both at rest and during wordprocessor work.

Adult↗
PubMed1989

On-line determination of anaerobic threshold with rms-EMG.

1. On-line monitoring of surface rms-EMG for detecting the anaerobic threshold during a cycle ergometer test was evaluated and compared with blood lactate and ventilatory parameters in 12 healthy icehockey players. 2. Dislinearity of increase in blood lactate level, ventilatory parameters and myoelectrical activity was observed at the mean work level of 300 (range 270-330) watts in each case. 3. The linearity disappeared at the same time in the rms-EMG-load ratio in working quadriceps and gastrocnemius muscles while also in nonworking frontalis muscle a change in EMG level was noticed. 4. The break point in rms-EMG did not correlate with the changes in skin humidity and temperature. No change was observed in spectral properties of the myoelectrical signals. 5. The rms-EMG follow-up is easier to perform than measurements of blood lactate and ventilatory parameters in the determination of anaerobic threshold.

Adolescent↗
PubMed1988

Shoulder strain in keyboard workers and its alleviation by arm supports.

Keyboard work consists mostly of dynamic contractions of the small muscles of the forearms and hands. This is accompanied by continuous activity in the arm, shoulder and neck muscles keeping the head and hand in the correct position. Eliminating the weight from the arm by means of support and the position of the arms influences the electrical activity of shoulder muscles when working at a keyboard. We studied the influence of elbow angle; as well as that of different arm supports, on electrical activity of upper trapezius muscle during keyboard work in healthy workers and persons suffering from shoulder pains. The measurements were carried out in the laboratory. EMG activities, which where measured as mean square root (RMS)-values at every 100-millisecond period in trapezius muscle when working, were lower, the greater the elbow angle. Furthermore electrical activity decreased when subjects used arm supports while working. It is evident that the static load to shoulder muscles can be lowered significantly in keyboard work, when the forearms are at an angle of at least 100 degrees and by using arm supports. The most convienient and ergonomic working position can also be found individually be the method used here.

Adult↗
PubMed1987

Timing of the triggering action of shooting in relation to the cardiac cycle.

The purpose of this study was to verify the timing of triggering in relation to the cardiac cycle in shooting. The test subjects were six Finnish rifle and pistol champions as well as three beginners at shooting. The electrical activity of the trigger finger muscle (m. flexor digitorum superficialis; surface electrodes) and the heart cycle were fed into a two-channel x-t recorder. The movements of the gun were recorded using a laser technique and, at the same time, cardiac cycles were also monitored. Results showed that the champion shooters triggered during diastole whereas the beginners triggered both during diastole and systole. The results of those beginners triggering during diastole were better than those triggering during systole.

Adult↗
PubMedDate not supplied

Real-time evaluation of anaerobic threshold with rms-EMG of working and nonworking muscles during incremental bicycle ergometer test.

Surface rms-EMG measurement as a real time monitoring method for detecting the anaerobic threshold during a bicycle ergometer test was evaluated and compared with blood lactate and ventilatory parameters. The study group consisted of 12 healthy ice hockey players. The anaerobic threshold indicated as dislinearity of increase in blood lactate level, ventilatory parameters and myoelectrical activity was observed at the work level of 300 (range 270-330) W in each case. The linearity disappeared at same time in the rms-EMG-load ratio both in working (quadriceps and gastrocnemius) and nonworking (frontalis) muscles. The rms-EMG follow-up was easier to perform than measurements of blood lactate and ventilatory parameters.

Adult↗
PubMedDate not supplied

The segmental dorsal ramus neuropathy as a common cause of chronic and recurrent low back pain.

The causes of recurrent and chronic low back pain usually remain unknown. The dorsal ramus lesion was found in 57 of 200 low back pain patients in this study in L5 or L4 segment without any neurophysiologic or neuroradiologic evidence of proximal ventral root compression. The neuropathy of dorsal rami, especially in their medial branches seems to be surprisingly common finding associated with low back pain and referred symptoms.

Adolescent↗
PubMedDate not supplied

Segmental hypermobility in lumbar spine and entrapment of dorsal rami.

Low back pain patients (N = 18) having segmental hypermobility in one lumbar segment and healthy controls (N = 13) were chosen for this study. Patients had no other structural spinal pathology except displacement of one vertebra to another in lateral X-ray bending pictures. Kinetic intramuscular EMG-activity from paraspinal muscles was studied off-line during back flexion and reextension. Routine needle EMG study of paraspinal muscles was also performed in addition to measurements of the tibial nerve H-reflexes and peroneal F-responses. Results showed that the number of MUAPs in erector spinae muscle on voluntary efforts was rarefied at hypermobile levels, and spontaneous activity, positive sharp waves and high frequency discharges were found in more than half of the patients in paraspinal muscles, usually at hypermobile levels only. No signs of proximal nerve root compression were found. This indicates neuropathy of dorsal rami at the instable level.

Adult↗