Knee function was evaluated by knee score, activity level, clinical findings and performance tests, muscle size by computerized tomography (CT), morphology by light (LM) and electron microscopy (EM), muscle function by electromyography (EMG) and isokinetic performance in 29 patients with chronic anterior cruciate ligament (ACL) tear. Preoperatively CT disclosed a significant mean atrophy of the quadriceps and nonsignificant changes of the other muscle areas of the injured leg. Morphology of m vastus lateralis of the injured leg was normal in more than half of the biopsies preoperatively, the rest showed signs of nonoptimal activation. Significant decreases in all isokinetic parameters were noticed together with significantly decreased EMG of the quadriceps muscle of the injured leg. Âfter surgical reconstruction the knees were immobilized in a cast for 6 weeks at either 30° or 70° of knee flexion. After cast removal CT showed significant decreases of all areas which also remained after training. The 30° group showed larger fibres (intracellular oedema) and more frequent morphological abnormalities than the 70° group. Fourteen weeks postoperatively the patients were allocated to either a combination of isometric and progressive resistance training or isokinetic training for 6 weeks. CT showed slightly larger areas at 20 weeks postoperatively than at 6 weeks. Morphological abnormalities were still prominent at 20 weeks postoperatively. Maximum isokinetic knee extensor mechanical output and endurance were markedly decreased at 14 weeks postoperatively but both improved progressively during the one year rehabilitation, mostly during the intensive 6 week training period but irrespective of training programme used. Fatiguability/endurance level improved over the preoperative level. Muscular work/integrated EMG was stable while EMG/t increased indicating neuromuscular relearning. The clinical result at 28 months foliowup was excellent or good in 93% of the patients and clinical stability improved in 66%. Independent upon primary knee immobilization angle or training programmes no differences could be demonstrated with respect to stability, range of motion, function or isokinetic mechanical output. Isokinetic performance was still significantly lower in the injured compared to the noninjured leg and not significantly different from the preoperative values. Morphology, only 6 cases, showed abnormalities similar to preoperative findings. In conclusion, the reason for the decreased maximum and total knee extensor performance in these patients with ACL tears is suggested to be nonoptimal activation of normal functioning muscle fibres depending on changes in knee joint receptor afferent inflow. No differences concerning the markedly improved postoperative clinical result could be seen between the different treatment modalities used. A nonoptimal muscular activation might explain the still decreased isokinetic performance present at followup. / <p>S. 1-40: sammanfattning, s. 43-137: 5 uppsatser</p> / digitalisering@umu.se

Swallowing impairment or dysphagia can be a consequence of several neurological and anatomical disorders such as stroke, Parkinson’s diseases, and head and neck cancer. Management of patients with dysphagia often involves diet modification, sensory stimulation, and exercise programme with the primary goal being safe swallowing to maintain nutrition. The aim of this project was to evaluate the effects of lemon odour and tastant on swallowing behaviour in healthy young adults. Specifically, the neural excitability and biomechanical characteristics of swallowing were measured in two studies. Neural excitability was evaluated by measuring motor-evoked potentials (MEPs) from the submental muscles which were evoked by transcranial magnetic stimulation (TMS) of the motor cortex. Biomechanical characteristics were evaluated through measures of submental muscle contraction, pressure changes in the oral cavity and pharynx, and the dynamics of the upper oesophageal sphincter (UES). Two groups of volunteers (16 in each group) participated in two separate studies. In the MEP study, 25% and 100% concentrations of lemon concentrate were presented separately as olfactory and gustatory stimuli. The four stimuli were randomly presented in four separate sessions. The olfactory stimulus was nebulized and presented via nasal cannula. Filter paper strips impregnated with the lemon concentrate placed on the tongue served as the gustatory stimulus. Tap water was used as control. TMS-evoked MEPs were measured at baseline, during control condition, during stimulation, immediately poststimulation, and at 30-, 60-, and 90-min poststimulation. Experiments were repeated using the combination of odour and tastant concentration that most significantly influenced the MEP. The biomechanical study used (a) surface electromyography (sEMG) to record contraction of the submental muscles, (b) lingual array with pressure transducers to record glossopalatal pressures, and (c) pharyngeal manometry to record pressures in the pharynx and the UES. Similar methods of presenting the stimuli were used to randomly present the 25% and 100% concentrations of lemon odour and tastant. All data were recorded concurrently during stimulation. The concentration of odour and tastant that produced the largest submental sEMG amplitude was selected for presentation of combined stimulation. Data were then recorded during combined stimulation and at 30-, 60-, and 90-min poststimulation. Results from the MEP study showed increased MEP amplitude at 30-, 60-, and 90-min poststimulation during swallowing compared to baseline, but only for the combined stimulation. Poststimulation results from the biomechanical study showed decreased middle glossopalatal pressure at 30 min and decreased anterior and middle glossopalatal contact duration at 60 min. No poststimulation changes were found in sEMG and pharyngeal manometry measures. During combined odour and tastant stimulation, there were increased pressure and contact duration at the anterior glossopalatal contact and decreased hypopharyngeal pressure. Generally, these changes correspond to increased efficiency of swallowing. In conclusion, these are the first studies to have measured the effects of flavour on neural excitability and biomechanics of swallowing and the first to have shown changes in MEP and several biomechanical characteristics of swallowing following flavour stimulation. These changes were present poststimulation, suggesting mechanisms of neural plasticity that may underlie potential value in the rehabilitation of patients with dysphagia.

Local twitch responses (LTRs) can be elicited by snapping palpation of myofascial trigger points (TrP) or TrP injections. Objective: To characterize the LTR elicited by TrP injection and snapping palpation on surface electromyography (sEMG) in subjects with myofascial pain in 14 female subjects. Methods: Surface EMG electrodes were placed around the TrP and a control site on the trapezius muscle. Then the following protocol was carried out: tension and contraction of the ipsilateral trapezius muscle, baseline resting activity (five minutes), snapping palpation of the TrP and the control sites, TrP injection, and final resting activity (five minutes). The following data were recorded: pain ratings, areas of referred pain, presence of LTR, and sEMG recordings. Results: During the TrP injection, the investigator found LTRs in only 36% of the subjects, while 64% of the subjects reported that they felt the LTR, and the sEMG recorded only one LTR in one subject. Despite the low percentage of LTRs elicited clinically (36%), a large number of subjects (71%) reported more than 50% immediate reduction in pain intensity after the TrP injection. Conclusion: The sEMG is unable to register the LTR elicited by snapping palpation and TrP injection.

Special Weapons and Tactics (SWAT) officers constitute a subgroup of specialized law enforcement officers that perform a variety of tactical operations while wearing approximately 40 kg of tactical gear. Lower back pain is a prevalent musculoskeletal injury suffered by SWAT officers. Tactical gear places significant stress on the lower back. Thus, it is important to quantify the effect that tactical gear has on muscle activation levels of torso musculature while performing occupational tasks. Electromyography was evaluated on 20 male subjects (age: 34.7±4.5 yr.; height: 1.79±.10 m; body mass: 91.53±17.32 kg; mass of gear: 13.82±1.90 kg) while performing four tactical tasks (standing, rifle walk, sitting, & shield walk) with and without gear. Electromyography was evaluated bilaterally on the erector spinae, rectus abdominis, and external oblique muscles. The dominant erector spinae (mean delta: +0.16%) and external oblique (mean delta: -0.124%) demonstrated significant changes in muscle activation with the addition of gear, which may indicate increased spinal compression. There were also trends of increased co-activation of core musculature with the addition of gear. The rifle walk and shield walk task mean muscle activations were significantly higher than the standing and sitting tasks. The shield walk produced the highest mean activations for each muscle. Physical training for SWAT officers should emphasize exercises that simulate task-specific movement patterns without gear to decrease the spinal compression associated with load carriage.

Background: Whiplash associated disorders (WAD) account for a large proportion of the overall impairment and disability from traffic injuries and causes substantial bio psychosocial consequences for some individuals. Aims: To increase the knowledge about factors described in terms of either function /impairment, activity/disability and life satisfaction in acute and chronic WAD as well as possible implications for rehabilitation. Within this aim the incidence and recovery rate of whiplash injury and prognostic factors of interest for early rehabilitation have been studied. Subjects and Methods: Fifty-five healthy controls and 34 WAD subjects were analysed within and between groups concerning a) biomechanical out put, endurance, fatigue and muscle tension (EMG activity of trapezius, infraspinatus and deltoideus) during repetitive shoulder forward flexion b) impairments and activity/disability and life satisfaction.356 subjects seeking medical attention due to whiplash trauma, 296 were available at follow up, mean 16 months post injury. Incidence and odds ratio of accident and other background factors on disability were determined. Thirty-four out of 43 patients with whiplash injury were investigated through quantitative sensory tests at six weeks and 71 months after injury. 62 WAD participated in an interdisciplinary rehabilitation program (a pilot study) designed to evaluate such rehabilitation program for patients with chronic (in relatively early stage) WAD. Program evaluation of impairment, disability and life satisfaction (prospective and retrospective) was carried out before and after program and at 6 months. Results: No significant effects of sex or age on the ability to relax between repetitive r muscle contractions (SAR) were found in healthy subjects (study I). Significantly higher inability to relax between contractions was found for the two portions of trapezius and infraspinatus in the WAD group compared to the healthy group (study II). Significantly lower levels of activity preferences were noted for three out of five indices in females with WAD The WAD group had significantly higher prevalence of neropsychological and emotional symptoms. Both pain related symptoms and neropsychological symptoms were of significant importance for aspects of disability and life satisfaction in this group (study IV). Sensory disturbances over the trigeminal skin area persisted over the years. At follow-up a significant correlation was found between the sensory disturbances and the symptoms related to the central nervous system while no significant relationship was found with the musculoskeletal symptoms (study HI) .The annual incidence according to the grading of the Quebec Task Force on Whiplash-Associated Disorders (WAD 1-3) was 3.2/1000 and 4.2/1000 when WAD 0 was included. Sixty-eight percent of the patients recovered during the follow-up Pre-traumatic neck pain, low educational level, female gender and WAD grade E-Ill were significantly associated with a poor prognosis (study IV). . Participants in the rehabilitation program reported increased coping ability. Stress reactions seemed rather frequent (32 %). Pain intensity in the neck and upper back were significantly decreased at 6 months follow-up. However, for most of the functional and psychological markers, no significant changes were found (study V). Conclusion: The higher prevalence of musculoskeletal complaints of the neck shoulder region in females cannot be explained by higher muscle tension and clinical assumption of increased muscle tension seems correct in whiplash patients Results indicate heterogeneity among WAD subjects. Females are at risk after a whiplash trauma but the severity of initial symptoms and signs also affect outcome as well as low education. High levels of neuropsychological symptoms and pain, signs of posttraumatic stress, fear and avoidance, loss of control, anxiety, bio-mechanical and psychosocial factors at work (studies) and social support are potential factors to be aware of. Extensive and costly investigations are in most cases not necessary. However most persons will recover a whiplash injury. Multidisciplinary/interdisciplinary assessment should be considered at three months if substantial negative effect on the person’s ability to function and health situation exists. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 2001, härtill 6 uppsatser.</p> / digitalisering@umu

In male athletes from different sports, isokinetic knee extensor, and in orienteers also plantar flexor peak torque (PT), contractional work (CW) and integrated surface electromyograms (iEMG) were analysed. Single contraction PT, CW and iEMG in sprinters and marathon runners were signi­ficantly correlated to the cross-sectional area (CSA) of m. quadriceps, and to the Type II fibre area of m. vastus lateralis. When correcting PT, CW and iEMG for CSA of m. quadriceps, such correlations were found only for Type IIA fibre area at 180° s~1. Elec- tromyographically, m. vastus lateralis (biopsied muscle) was representative for m. quadriceps. Calculated optimal mean power (CW s~1) and electrical efficacy (CW/iEMG) approximated for sprinters 450° s-1 and for marathon runners 270° s~1, i.e. velocities at or above the upper limit of the dynamometers. In orienteers, plantar flexor PT increased during winter training, but decreased during competitive season. Knee extensor PT increased over the whole year. At 30 and 60° s~1 only knee extensor PT was negatively associated with the running velocity at onset of blood lactate accu­mulation (VOBLA)- Changes in VOBLA during winter period were negatively associated with changes in knee extensor PT at 180° s~1. During competitive season, changes in Vobla were negatively associated with the ratio quality : quantity running. In ice hockey players PT varied non-systematically with training and games. The biopsy specimens of marathon runners showed irregular fibre shapes, an in­creased amount of connective tissue and central fibre nuclei, indicating an early strain disease or functional adaptation to extreme demands. During repetitive contractions in sprinters and marathon runners, fatigue, i.e. slope of decline in CW, was significantly associated with the Type II fibre area of m. vastus lateralis. For knee extensors of sprinters, ice hockey players and orienteers, a steep de­crease in CW/iEMG was observed. In contrast, knee extensors of marathon runners and plantar flexors of orienteers showed an almost unaltered CW/iEMG throughout the test. The knee extensor endurance level (CW/iEMG) was significantly correlated to the maximal oxygen uptake. In orienteers, an increase in endurance level of both tested muscle groups during winter training parallelled an increase in VOBLA and V02obla- In hockey players, fatigue and endurance pattern (CW and CW/iEMG) changed non-systematically with training and games. In conclusion, isokinetic measurements and iEMG reflect the structural properties of the knee extensor muscles in sprinters and marathon runners. The demonstrated characteristics and changes in leg muscle function in different groups of athletes apparently reflect varying demands from different sports activities. / <p>S. 1-31: sammanfattning, s. 33-84: 6 uppsatser</p> / digitalisering@umu

Abstract Aim: The main objective of this study was to compare electro mechanical delay (EMD) and rate of torque development (RTD) of the knee extensors 6 weeks after rehabilitation of anterior cruciate ligament reconstruction (ACLR) with or without neuromuscular electrical stimulation (NMES). Further the feasibility of the study was examined. Method: 10 participants were randomized into two groups, one neuromuscular electrical stimulation group (NMESG) and one training group (TG). The NMESG used a NMES-device as a complement to the ordinary rehabilitation protocol. Regular meetings with a physiotherapist were scheduled during the rehabilitation. Measurements of RTD and EMD during knee extension were made in an isokinetic dynamometer with electromyography recordings (EMG) from the knee extensors 6 weeks after surgery. Results: All participants completed the study. The NMESG went to see the physiotherapist 6.7 ± 2.5 times and the TG 6.8 ± 1.8 times. The participants in the NMESG used the NMES-apparatus 28 ± 1.7 times. Total number of training days for the NMESG was 25 ± 4 and for the TG 35 ± 1. RTD did not significantly differ between the groups. For the TG, RDT was 901.1, 941.2 and 531.0 Nm/s, over the first 50, 100 and 200 ms, respectively. For NMESG: RTD was 824.3, 966.2 and 529.0 Nm/s, over the first 50, 100 and 200 ms, respectively. No significant difference between the groups or interaction between group and muscle was found in EMD. For both groups EMD was significantly larger for vastus medialis as compared to the vastus lateralis and rectus femoris. Conclusions: The study was feasible to perform, and despite fewer training days for the NMESG, no significant group differences were found in RTD or EMD. A larger study population is needed to evaluate the efficacy of the intervention. / Abstrakt Syfte: Huvudsyftet med denna studie var att jämföra elektromekaniska fördröjning (EMD) och vridmoment utveckling (RTD) för knäextensorerna 6 veckor efter rehabilitering av främre korsbandsrekonstruktion (ACLR) med eller utan neuromuskulär elektrisk stimulering (NMES). Vidare undersöktes genomförbarheten av studien. Metod: 10 deltagare randomiseras in i två grupper, en neuromuskulär elektrisk stimulerings grupp (NMESG) och en träningsgrupp (TG). NMESG använde en NMES - enhet som ett komplement till ordinarie rehabiliteringsprotokoll. Regelbundna möten med sjukgymnast var inplanerad under rehabiliteringen. Mätningar av RTD och EMD under knäets extension gjordes i en isokinetisk dynamometer med elektromyografi inspelningar (EMG) från knäextensorerna 6 veckor efter operationen. Resultat: Alla deltagare fullföljde studien. NMESG träffade sjukgymnasten 6,7 ± 2,5 gånger och TG 6,8 ± 1,8 gånger. Deltagarna i NMESG använde NMES - apparaten 28 ± 1,7 gånger. Totalt antal träningsdagar för NMESG var 25 ± 4 och för TG 35 ± 1. RTD skiljde sig inte signifikant mellan grupperna. För TG var RDT 901,1, 941,2 och 531,0 Nm/s, under de respektive första 50, 100 och 200 ms. För NMESG var RTD 824,3, 966,2 och 529,0 Nm/s, under de respektive första 50, 100 och 200 ms. Inga signifikanta skillnader mellan grupperna eller samspel mellan grupp och muskler hittades i EMD. För båda grupperna var EMD signifikant större för vastus medialis jämfört vastus lateralis och rectus femoris. Slutsats: Studien var möjligt att utföra, och trots färre träningsdagar för NMESG sågs inga signifikanta skillnader mellan grupperna i RTD eller EMD. Det behövs en större studiepopulation för att utvärdera effekten av interventionen.

Darbo tikslas – įvertinti nugaros giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant pratimus atviroje kinetinėje grandinėje. Pasirinktam darbo tikslui įgyvendinti buvo iškelti šie uždaviniai: 1. Įvertinti nugaros giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant pratimus atviroje kinetinėje grandinėje ant stabilios atramos. 2. Įvertinti nugaros giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant pratimus atviroje kinetinėje grandinėje ant nestabilios atramos. 3. Palyginti giliųjų raumenų elektrinį aktyvumą su paviršinių raumenų elektriniu aktyvumu kiekvieno pratimo metu. 4. Palyginti raumenų elektrinį aktyvumą tarp identiškų pratimų, atliekamų ant stabilios atramos, su atliekamais ant nestabilios atramos. 5. Palyginti raumenų elektrinį aktyvumą tarp identiškų pratimų, kurių atlikimas skiriasi judesyje dalyvaujančių apatinių galūnių skaičiumi. Tyrime dalyvavo 20 darbingo amžiaus vyrų, per tris mėnesius neturėjusių nusiskundimų dėl nugaros apatinės dalies skausmo. Tyrimą sudarė dvi dalys: 15 minučių trukmės tiriamųjų apšilimas (5 minutės veloergometro mynimui ir 10 minučių tempimo pratimams) ir tiriamųjų testavimas. Tiriamųjų testavimą sudarė 11 pratimų ir 2 testavimo padėtys maksimaliam valingam testuojamų raumenų susitraukimui išgauti. Išvados: 1. Dauginio raumens elektrinis aktyvumas buvo didesnis nuo 19,5 % iki 27,8 % nei tiesiamojo nugaros raumens krūtininės dalies elektrinis aktyvumas penkiuose iš septynių pratimų, atliekamų ant stabilios... [toliau žr. visą tekstą] / The purpose of this research: To evaluate electric activity of deep and superficial back muscles during open kinetic chain exercises. Goals of this research: 1. To evaluate electric activity of deep and superficial back muscles during open kinetic chain exercises performed on stable support. 2. To evaluate electric activity of deep and superficial back muscles during open kinetic chain exercises performed on labile support. 3. To compare electric activity of deep and superficial back muscles during each exercise. 4. To compare electric activity of back muscles between the same exercise pairs performed on different support type. 5. To compare electric activity of back muscles during exercise performed with one lower limb with exercise performed with both lower limbs. During this research 20 men, who had no recent complaints about low back pain (>3 months), were tested. The testing consisted of two parts: 15 min. for warm up exercises (5 min. – cardio respiratory warm up and 10 min. – stretching exercises) and the main testing. The main testing consisted of 11 exercises and 2 exercise to determine maximum voluntary contraction. Conclusion: 1. Electric activity of multifidus muscle was statistically significant higher than electric activity of thoracic part of erector spinae muscle during 5 from 7 exercises performed on stable support (p<0,05). 2. Electric activity of multifidus muscle was statistically significant higher than electric activity of thoracic part of erector spinae... [to full text]

Cross-correlation is often used as the primary technique to compare two biological signals. The cross-correlation technique is an effective means to measure the synchronization of two signals if the relative phases at all frequencies are distributed linearly, that is, there is a group delay. The group delay assumption of cross-correlation analysis imposes an unfavourable restriction on signals with relative phase correlation which varies at different frequencies. Traditional Fourier analysis applied to a short data segments, namely the Short Time Fourier Transform (STFT), provides phase information for each frequency component, but it is not suitable for biological signals with non-stationary statistics for which the ideal segment length is unknown. The application of a wavelet based phase analysis technique is discussed in this study. The frequency decomposition and temporally localized nature of the wavelet transform provides localized phase-frequency information for two signals. A wavelet frequency temporal relative phase pattern (WFT-RPP) technique to extract relative phase information at specific frequencies over the time course of a time-varying signal was developed. The technique was tested on simulated data and surface electromyographic (sEMG) data recorded from upper limb muscles in human subjects as they performed a series of dynamic push and pull tasks. Selected sEMG channel pairs are compared against each other using the WFT-RPP technique to extract the relative phase information and repetitive relative phase patterns for certain muscle pairs were observed. The properties of the WFT-RPP and the merits and weaknesses of using the technique for determining intermuscular sEMG synchronization is discussed. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2011-09-13 11:58:16.014

In this thesis sensorimotor integration in the human spinal cord was investigated in the intact (Chapters 2 and 3) and injured nervous systems (Chapter 4-stroke; Chapter 5-spinal cord injury (SCI)). In Chapter 2, I characterized a short-latency reflex pathway between sensory receptors of the lower leg and the erector spinae (ES) muscles of the lower back that may play a role in the maintenance of posture and balance. The ES reflexes were evoked bilaterally by taps applied to the Achilles tendon and were modulated by task. Furthermore, these reflexes involved a larger contribution from cutaneous receptors in the lower limb, rather than muscle spindles. In Chapter 3, I investigated changes in reflex transmission along the H-reflex pathway throughout 10 s trains of neuromuscular electrical stimulation (NMES) using physiologically relevant frequencies (5-20 Hz) and during functionally relevant tasks (sitting and standing) and background contraction amplitudes (up to 20% MVC). The results of this study revealed strong post-activation depression of reflex amplitudes, followed by significant recovery during the stimulation, both of which were influenced by stimulation frequency and background contraction amplitude, but not task. During 10 Hz stimulation, reflex amplitudes showed complete recovery (i.e. back to their initial values), and at times, complete recovery occurred by the third reflex in the train. These results demonstrate that transmission along the H-reflex pathway is modulated continuously during periods of repetitive input. In Chapters 4 and 5, I studied the extent to which a novel stimulation protocol that incorporated wide pulse widths (1 ms) and high frequencies (up to 100 Hz) (wide-pulse NMES; WP-NMES), could enhance electrically-evoked contractions through a central contribution in individuals with stroke or SCI. This central effect arises from the electrical activation of sensory axons, which in turn, reflexively recruit motoneurons in the spinal cord. After stroke, contractions evoked by WP-NMES were larger in the paretic arm than the non-paretic arm. After SCI, transmission along the H-reflex pathway was observed throughout trains of WP-NMES; direct evidence of a central contribution. These results suggest that maximizing the central contribution during WP-NMES may be useful for maintaining muscle quality after neurological injury.