Categories and frequencies of leisureactivities employed by 156 randomly selected males and females aged 40-44, 50-54, 60-64 were investigated by structured interviews and were related to leisuresatisfaction, to experienced health and socio-economic status. In equal numbers (15) of males and females from each group and in 24 males (60 +_6 years) with intermittent claudication (Cl) isokinetic plantar flexion performance was investigated with registrations of peak torque (PT), contractional work (CW), active range-of-motion (RoM) and integrated electromyograms from all threee triceps surae heads. Subjects performed a few maximum plantarflexions at different velocities of angular motion and also up to 200 consecutive plantar flexions at 60 °/s. The males aged 40-44 were re -investigated after two years additionally using electromyographic power frequency analyses. Leisure choice was mainly age and sex independent and extensively included outdoor activities. Leisure satisfaction was positively associated with relative frequency of activities. Symptoms of bodily discomfort, in particular backpain, were quite common and apparently caused relatively low level of mutual leisure activities. Thus, with in this age span, leisure activities appear rather rigid but often successfully, adhered to . Common ailments influence partnership mutuality negatively. Plantar flexion PT and CW are adequately p re dicta ble by sex, age and crural circumference. Uniformly a 3:2 male/female ratio characterizes mechanical output and iEMG. The latter is velocity independent. Output decreases with increasing age. Hence the output/excitation balance (CW/iEMG) is age, but not sex, dependent. CI-patients produce less PT and CW than do controls. Independently of this disease, of age and sex, PT and CW describe parallel negative exponential functions of velocity. During repeated manoeuvres plantar flexion output and iEMG initially drop, there after to maintain nearly steady-state levels. Throughout up to 200 contractions CW/iEMG was unaltered in the clinically healthy. Test/re-test with two years interval yielded nearly identical results. Leftshifts in mean power frequency in parallel with output-drop imply that the latter probably is due to FT-motor unit fatigue. For CW, but not for PT, the drop became slower and the (relative) steady-state level higher with increasing age, indicating significant increase in endurance with age. In the Cl-patients, output, but not excitation, decreased after a few repititions. Therefore, CW/iEMG fell dramatically, implying intramuscular fatigue. Taken together with findings of close associations between total cumulated work and measured/expected maximum walking tole rance it is suggested that measurements of CW and calculations of CW/iEMG are of clinical value. / <p>Härtill 5 uppsatser</p> / digitaliserinlg@umu.se

Darbo tikslas: įvertinti pilvo giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant uždaros ir atviros kinetinės grandinės pratimus. Uždaviniai: 1. Įvertinti pilvo giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant pratimus ant stabilios atramos. 2. Įvertinti pilvo giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant pratimus ant nestabilios atramos. 3. Įvertinti pilvo giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant atviros kinetinės grandinės pratimus. 4. Įvertinti pilvo giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant uždaros kinetinės grandinės pratimus. 5. Įvertinti skirtingų, pilvo raumenims lavinti skirtų pratimų atlikimo metu gautą pilvo giliųjų ir paviršinių raumenų elektrinį aktyvumą. Tyrimo metodai: Tyrime dalyvavo 20 darbingo amžiaus vyrų, per tris mėnesius neturėjusių nusiskundimų dėl apatinės nugaros dalies skausmo. Tyrimo pradžioje tiriamajam buvo duodama 15 minučių apšilimo programa, po kurios sekė 8 testuojant naudotų pratimų atlikimas. Ant tiriamojo priklijuotais paviršiniais elektrodais, elektromiografu Myotrace 400 buvo registruojamas ir užrašomas raumenų elektrinis aktyvumas. Išvados: 1. Didžiausias raumenų elektrinis aktyvumas buvo atliekant liemens lenkimą kulnais spaudžiant dėžutę sėdmenų link ant stabilios atramos (p<0,05). Didžiausias santykinis giliųjų-paviršinių pilvo raumenų aktyvumas buvo atliekant liemens lenkimo atremtyje ant delnų ir kelių pratimą. 2. Atliekant pratimus ant nestabilios atramos... [toliau žr. visą tekstą] / The aim: to assess deep and superficial abdominal muscles electrical activity during open and closed kinetic chain exercises. Objectives: 1. To evaluate the surface and deep abdominal muscle electrical activity during exercise on a stable support. 2. To evaluate the surface and deep abdominal muscle electrical activity during the exercises on unstable supports. 3. To evaluate the surface and deep abdominal muscle electrical activity during a open kinetic chain exercises. 4. To evaluate the surface and deep abdominal muscle electrical activity during closed kinetic chain exercises. 5. To evaluate the surface and deep abdominal muscle electrical activity in variation of the abdominal exercises. Research metods: A total of 20 working-age men during the three months had no complaints of lower back pain. In the beginning of study the research was given 15 minutes to warm-up program, which was followed by eight testing exercises performance. Electromyograph Myotrace 400 has been registered and recorded muscles electrical activity by glued onto the skin surface electrodes. Conclusions: 1. The maximum muscle electrical activity was during trunk flexion with pressing the box by the heels toward the buttocks on the stable surface (p<0,05). The highest ratio of surface-deep abdominal muscle activity was during trunk flexion facing on the palms and knees. 2. During the exercises on unstable surface the highest muscle electrical activity was in trunk flexion exercise with pressing the... [to full text]

This study investigated the EMG muscle activation patterns of forward ice hockey skating at three velocities. Seven varsity hockey players from McGill University (age = 22.1 +/- 1.2 years, height = 1.8 +/- 0.1m, weight = 82.1 +/- 8.5 kg) participated. Testing was done using a skating treadmill. Skin was shaved, abraded and cleansed in the area of the electrode placement over the vastus medialis (VM), adductor magnus (AM), biceps femoris (BF), gluteus maximus, tibialis anterior (TA), peroneus longus (PL), and lateral gastrocnemius (GL) of the right lower limb. Subjects skated at 12 km/hr, 18 km/hr, and 24 km/hr. Repeated measures ANOVAs were performed, followed by Tukey post hoc tests. In general, the amplitude at speed 24km/hr was significantly higher than the speed of 12km/hr. There were few significant differences in temporal values. In conclusion, this study has shown that an increase in velocity results in an increase in the amount of muscle activation, but the muscle coordination patterns remain the same.

No description available.

We developed a novel approach that requires subjects to produce and finely tune ground reaction forces (GRFs) while standing. Using this method we were able to identify specific contributions of individual muscles and how these contributions change with the effects of age. One of the aims of this investigation was to determine whether electromyographic data in our findings was due to random muscle activation or representative of a neuromuscular control strategy. Ten healthy young adults (5 male, 5 female) with their dominant foot fixed within a boot mounted to a force platform participated twice in a target matching protocol, requiring subjects to control both the direction and magnitude of GRF along the horizontal plane while maintaining constant inferior-superior loads of 50% body-weight. Subjects were asked to manoeuvre a cursor with their dominant leg to match a series of targets projected on a screen. Targets appeared at random one at-a-time, separated by 30o around a circular trajectory. Subjects applied loads to the force platform in various horizontal directions to move the cursor while also controlling body weight. A successful target match required subjects to maintain 50% body weight and 30% of their peak horizontal load for one second. Electromyography (EMG) of eight muscles that cross the knee joint, ground reaction forces, and kinematic data were recorded for each successful match. EMG was normalized to percent maximum voluntary isometric contractions collected on an isokinetic dynamometer. Each target matching session was separated by two-three days. A random model, single measures intra-class correlation analysed the reliability for both test-retest and intra-day results, in addition to intersubject reliability. We observed moderate to high ICC values (0.60 – 0.993) for most muscles in most directions, indicating low within-subject variance. In addition, moderate to high between-subject reliability was observed in all eight muscle activation profiles, indicating subjects used similar neuromuscular control strategies to achieve the desired GRFs. Our findings support that groups who have undergone the same number of testing sessions can be compared, and that a single testing session is all that is required to compare neuromuscular control strategies used by a group to achieve target locations. The second aim of this investigation was to evaluate age related differences in neuromuscular control about the knee joint using our target match protocol. Thirty-three healthy adults (17 younger 24 years ±2, 16 older 59 years ±5), completed the same protocol evaluated above. The mean magnitude of muscle activity, specificity index, and mean direction of muscle activity were calculated in each target direction. Older adults presented with significantly lower strength in knee flexion and extension, hip abduction, and ankle plantar flexion. Significantly (p<0.25) higher mean activation magnitudes in the rectus femoris, vastus lateralis, vastus medialis, biceps femoris, semitendinosus, medial gastrocnemius, and tensor facia lata were also observed. Intraclass correlations (ICC) magnitudes indicate the percentage of global variance that can be explained by within subject and between trial variability. Muscle activation patterns were found to be similar in all muscles (ICC≤0.82). Similar patterns are supported by non-significant differences in mean direction of activation and muscle activation specificity. These results indicated that healthy older adults utilise different activation magnitudes for stabilising the knee while maintain similar muscle activation synergies in all muscles to younger adults.

Qualitative studies investigating the sexual activity of people with low back pain found a substantial reduction in the frequency of coitus and have shown that pain during coitus due to mechanical factors (i.e., movements and postures) are the primary reason for this decreased frequency. However, a biomechanical analysis of coitus has never been done. The main objective of this study was to describe male and female lumbar spine and hip motion and muscle activation patterns during coitus and compare these motions and muscle activity across five common coital positions. Specifically, lumbar spine and hip motion in the sagittal plane and electromyography signal amplitudes of selected trunk, hip, and thigh muscles were described and compared. A secondary objective was to determine if simulated coitus could be used in place of real coitus for future coitus biomechanics research. Ten healthy males (29.3 ± 6.9 years, 176.5 ± 8.6 centimeters, 84.9 ± 14.5 kilograms) and ten healthy females (29.8 ± 8.0 years, 164.9 ± 3.0 centimeters, 64.2 ± 7.2 kilograms) were included for analysis in this study. These couples had approximately 4.7 ± 3.9 years of sexual experience with each other. This study was a repeated-measures design, where the independent variables, coital position and condition, were varied five (i.e., QUADRUPED1, QUADRUPED2, MISSIONARY1, MISSIONARY2, and SIDELYING) and two (i.e., real and simulated) times, respectively. Recruited participants engaged in coitus in five pre-selected positions (presented in random order) for 20 seconds per position first in a simulated condition, and again in a real condition. Three-dimensional (3D) lumbar spine and hip kinematic data were continuously collected for the duration of each trial by optoelectronic and electromagnetic motion capture systems. Electromyography (EMG) signals were also continuously collected for the duration of each trial. The kinematic data and EMG signals were collected simultaneously for both participants. Five sexual positions were chosen for this study based on the findings of previous literature and a biomechanical rationale. QUADRUPED – rear-entry, female quadruped, male kneeling behind – had two variations; in QUADRUPED1 the female was supporting her upper body with her elbows and in QUADRUPED2 the female was supporting her upper body with her hands. MISSIONARY – front-entry, female supine, male prone on top – also had two variations; in MISSIONARY1 the female was not flexing her hips or knees and the male was supporting his upper body with his hands, but in MISSIONARY2, the female was flexing her hips and knees and the male was supporting his upper body with his elbows. SIDELYING – rear-entry, female side-lying on her left side, male side-lying behind – did not have any variations. To determine if each coital position had distinct spine and hip kinematic and muscle activation profiles, separate univariate general linear models (GLM) (factor: coital position = five levels, α=0.05) followed by Tukey’s honestly significant difference (HSD) post hoc analysis were used. To determine if simulated coitus was representative of real coitus across all spine and hip kinematic and muscle activation outcome variables, paired-sample t-tests (α=0.05) were performed on all outcome variables for the real condition and their respective simulated values. In general, the coital positions studied showed that, for both males and females, coitus is mainly a flexion-extension movement of the lumbar spine and hips. Males used a greater range of their spine and hip motion in comparison to females. As expected, differences were found between coital positions for males and females and simulated coitus was not representative of real coitus, in particular the spine and hip kinematic profiles. The results found in this biomechanical analysis of common coital positions may be useful in a clinical context. It is recommended that during the acute stage of a low back injury resulting in flexion-, extension-, or motion-intolerance that coitus be avoided. If the LBP is a more chronic issue, particular common coital positions should be avoided. For the flexion-intolerant male patient, avoid SIDELYING and MISSIONARY2 as they were shown to require the most flexion. Both variations of QUADRUPED are the more spine-sparing of coital positions followed by, MISSIONARY1. Coaching the male patient on proper hip-hinging technique while thrusting – an easy technique to incorporate in both variations of QUADRUPED – will likely decrease spine movement and increase the spine-sparing quality of QUADRUPED. For the flexion-intolerant female patient, avoid both variations of MISSIONARY, especially with hip and knee flexion, as they were shown to elicit the most spine flexion. QUADRUPED2 and SIDELYING are the more spine-sparing coital positions, followed by QUADRUPED1. Subtle posture changes for a coital position should not be considered lightly; seemingly subtle differences in posture can change the spine kinematic profile significantly, resulting in a coital position that was considered spine-sparing becoming a position that should be avoided. Thus, spine-sparing coitus appears to be possible for the flexion-, extension-, and motion-intolerant patient. Health care practitioners may recommend appropriate coital positions and coach coital movement patterns, such as speed control and hip-hinging. With respect to future research in the area of sex biomechanics, using simulated coitus in replace of real coitus is not justifiable according to the data of this study. However, including a simulated condition did prove beneficial for increasing the comfort level of the couples and allowing time to practice the experimental protocol. Future directions may address female-centric positions (e.g., ‘reverse missionary’ with male supine and female seated on top), and back-pained patients with and without an intervention (e.g., movement pattern coaching or aides, such as a lumbar support).

Anti-pronation taping is commonly used by clinicians in the management of lower limb musculoskeletal pain and injury. Despite its frequent use in the clinical setting the mechanism(s) underlying its efficacy is not completely understood. For example, there is evidence that anti-pronation taping produces a biomechanical effect, but there has been little investigation of other mechanisms such as neurophysiological or psychological effects. Additionally, studies to date have been performed in mostly asymptomatic populations and have focused on the initial effect of tape (i.e. immediately following application and through a short duration of activity). Improved understanding of the underlying physiological mechanism(s) of anti-pronation tape is likely to facilitate improved knowledge of the technique, which may optimise its clinical application and contribute to clinical selection guidelines. The aims of this thesis were developed to address several of the limitations in the current anti-pronation taping literature. To facilitate an investigation of the comparative initial physiological effect of anti-pronation tape in a symptomatic and asymptomatic population, the first aim of this thesis was to compare neuromotor control (control of muscle activation and movement patterns) of gait, foot posture and foot mobility between asymptomatic individuals and individuals with a history of exercise related leg pain. The second aim of this thesis was to investigate the initial physiological effects of anti-pronation tape, specifically its neurophysiological (i.e. effect on muscle activation patterns) and biomechanical (i.e. effect on movement patterns, foot posture, foot mobility) effects. Thirdly this thesis aimed to investigate the duration of these initial physiological effects following tape removal. The fourth and fifth aims were to investigate the long term biomechanical and neurophysiological effects of anti-pronation taping i.e. following continual use over a clinically relevant period. In the first instance our aim was to investigate the effect of continual use on neuromotor control of gait, foot posture and foot mobility, and secondly to investigate the effect of continual use on the technique’s initial neurophysiological and biomechanical effects. Individuals with exercise related leg pain demonstrated lower activation of gluteus medius and lateral gastrocnemius during gait, but we observed no differences in lower limb movement patterns or foot posture and foot mobility between the two groups. The initial effect of tape was similar in individuals with and without exercise related leg pain. Specifically application of tape produced a reduction in activation of tibialis posterior, tibialis anterior and medial gastrocnemius, and increased activation of peroneus longus. There was a reduction in foot mobility, ankle plantarflexion and abduction excursion and an increase in ankle dorsiflexion and adduction excursion. Reduced muscle activation and increased motion was also observed at more proximal segments (knee, hip, pelvis), but were of smaller magnitude than at the foot and ankle. Changes in foot mobility, ankle kinematics and leg muscle activity did not continue following the removal of tape, but at more proximal segments (i.e. pelvis, hip and knee) small changes in kinematics and muscle activity were observed following the removal of tape. In regards to long term effects, continual use of tape for approximately 12 days produced a small increase in arch height when compared to a control. We did not observe a change in muscle activation or motion patterns, nor did continual use of the technique influence its initial neurophysiological or biomechanical effects (i.e. reduction in muscle activity, reduction in foot mobility, altered lower limb motion). The studies from this thesis provide evidence that anti-pronation tape should be considered in the management of individuals where reduced midfoot mobility, control of ankle motion or reduced activation of the leg muscles is desired, regardless of symptomatic status. When applied for approximately 12 days, anti-pronation tape produced a small increase in arch height ratio, but no alteration in neuromotor control. We are not aware of any definitive data on what constitutes a clinically meaningful increase in arch height, but results from a published case series suggests that our findings of a small increase in arch height may be clinically relevant for the treatment of lower extremity overuse injuries. Continual use of tape for a clinically relevant period does not alter its initial effects on foot posture and mobility or neuromotor control during gait. It would appear that the initial effects of anti-pronation tape are robust even after continuous use over a period of 11 days.

Anti-pronation taping is commonly used by clinicians in the management of lower limb musculoskeletal pain and injury. Despite its frequent use in the clinical setting the mechanism(s) underlying its efficacy is not completely understood. For example, there is evidence that anti-pronation taping produces a biomechanical effect, but there has been little investigation of other mechanisms such as neurophysiological or psychological effects. Additionally, studies to date have been performed in mostly asymptomatic populations and have focused on the initial effect of tape (i.e. immediately following application and through a short duration of activity). Improved understanding of the underlying physiological mechanism(s) of anti-pronation tape is likely to facilitate improved knowledge of the technique, which may optimise its clinical application and contribute to clinical selection guidelines. The aims of this thesis were developed to address several of the limitations in the current anti-pronation taping literature. To facilitate an investigation of the comparative initial physiological effect of anti-pronation tape in a symptomatic and asymptomatic population, the first aim of this thesis was to compare neuromotor control (control of muscle activation and movement patterns) of gait, foot posture and foot mobility between asymptomatic individuals and individuals with a history of exercise related leg pain. The second aim of this thesis was to investigate the initial physiological effects of anti-pronation tape, specifically its neurophysiological (i.e. effect on muscle activation patterns) and biomechanical (i.e. effect on movement patterns, foot posture, foot mobility) effects. Thirdly this thesis aimed to investigate the duration of these initial physiological effects following tape removal. The fourth and fifth aims were to investigate the long term biomechanical and neurophysiological effects of anti-pronation taping i.e. following continual use over a clinically relevant period. In the first instance our aim was to investigate the effect of continual use on neuromotor control of gait, foot posture and foot mobility, and secondly to investigate the effect of continual use on the technique’s initial neurophysiological and biomechanical effects. Individuals with exercise related leg pain demonstrated lower activation of gluteus medius and lateral gastrocnemius during gait, but we observed no differences in lower limb movement patterns or foot posture and foot mobility between the two groups. The initial effect of tape was similar in individuals with and without exercise related leg pain. Specifically application of tape produced a reduction in activation of tibialis posterior, tibialis anterior and medial gastrocnemius, and increased activation of peroneus longus. There was a reduction in foot mobility, ankle plantarflexion and abduction excursion and an increase in ankle dorsiflexion and adduction excursion. Reduced muscle activation and increased motion was also observed at more proximal segments (knee, hip, pelvis), but were of smaller magnitude than at the foot and ankle. Changes in foot mobility, ankle kinematics and leg muscle activity did not continue following the removal of tape, but at more proximal segments (i.e. pelvis, hip and knee) small changes in kinematics and muscle activity were observed following the removal of tape. In regards to long term effects, continual use of tape for approximately 12 days produced a small increase in arch height when compared to a control. We did not observe a change in muscle activation or motion patterns, nor did continual use of the technique influence its initial neurophysiological or biomechanical effects (i.e. reduction in muscle activity, reduction in foot mobility, altered lower limb motion). The studies from this thesis provide evidence that anti-pronation tape should be considered in the management of individuals where reduced midfoot mobility, control of ankle motion or reduced activation of the leg muscles is desired, regardless of symptomatic status. When applied for approximately 12 days, anti-pronation tape produced a small increase in arch height ratio, but no alteration in neuromotor control. We are not aware of any definitive data on what constitutes a clinically meaningful increase in arch height, but results from a published case series suggests that our findings of a small increase in arch height may be clinically relevant for the treatment of lower extremity overuse injuries. Continual use of tape for a clinically relevant period does not alter its initial effects on foot posture and mobility or neuromotor control during gait. It would appear that the initial effects of anti-pronation tape are robust even after continuous use over a period of 11 days.

Anti-pronation taping is commonly used by clinicians in the management of lower limb musculoskeletal pain and injury. Despite its frequent use in the clinical setting the mechanism(s) underlying its efficacy is not completely understood. For example, there is evidence that anti-pronation taping produces a biomechanical effect, but there has been little investigation of other mechanisms such as neurophysiological or psychological effects. Additionally, studies to date have been performed in mostly asymptomatic populations and have focused on the initial effect of tape (i.e. immediately following application and through a short duration of activity). Improved understanding of the underlying physiological mechanism(s) of anti-pronation tape is likely to facilitate improved knowledge of the technique, which may optimise its clinical application and contribute to clinical selection guidelines. The aims of this thesis were developed to address several of the limitations in the current anti-pronation taping literature. To facilitate an investigation of the comparative initial physiological effect of anti-pronation tape in a symptomatic and asymptomatic population, the first aim of this thesis was to compare neuromotor control (control of muscle activation and movement patterns) of gait, foot posture and foot mobility between asymptomatic individuals and individuals with a history of exercise related leg pain. The second aim of this thesis was to investigate the initial physiological effects of anti-pronation tape, specifically its neurophysiological (i.e. effect on muscle activation patterns) and biomechanical (i.e. effect on movement patterns, foot posture, foot mobility) effects. Thirdly this thesis aimed to investigate the duration of these initial physiological effects following tape removal. The fourth and fifth aims were to investigate the long term biomechanical and neurophysiological effects of anti-pronation taping i.e. following continual use over a clinically relevant period. In the first instance our aim was to investigate the effect of continual use on neuromotor control of gait, foot posture and foot mobility, and secondly to investigate the effect of continual use on the technique’s initial neurophysiological and biomechanical effects. Individuals with exercise related leg pain demonstrated lower activation of gluteus medius and lateral gastrocnemius during gait, but we observed no differences in lower limb movement patterns or foot posture and foot mobility between the two groups. The initial effect of tape was similar in individuals with and without exercise related leg pain. Specifically application of tape produced a reduction in activation of tibialis posterior, tibialis anterior and medial gastrocnemius, and increased activation of peroneus longus. There was a reduction in foot mobility, ankle plantarflexion and abduction excursion and an increase in ankle dorsiflexion and adduction excursion. Reduced muscle activation and increased motion was also observed at more proximal segments (knee, hip, pelvis), but were of smaller magnitude than at the foot and ankle. Changes in foot mobility, ankle kinematics and leg muscle activity did not continue following the removal of tape, but at more proximal segments (i.e. pelvis, hip and knee) small changes in kinematics and muscle activity were observed following the removal of tape. In regards to long term effects, continual use of tape for approximately 12 days produced a small increase in arch height when compared to a control. We did not observe a change in muscle activation or motion patterns, nor did continual use of the technique influence its initial neurophysiological or biomechanical effects (i.e. reduction in muscle activity, reduction in foot mobility, altered lower limb motion). The studies from this thesis provide evidence that anti-pronation tape should be considered in the management of individuals where reduced midfoot mobility, control of ankle motion or reduced activation of the leg muscles is desired, regardless of symptomatic status. When applied for approximately 12 days, anti-pronation tape produced a small increase in arch height ratio, but no alteration in neuromotor control. We are not aware of any definitive data on what constitutes a clinically meaningful increase in arch height, but results from a published case series suggests that our findings of a small increase in arch height may be clinically relevant for the treatment of lower extremity overuse injuries. Continual use of tape for a clinically relevant period does not alter its initial effects on foot posture and mobility or neuromotor control during gait. It would appear that the initial effects of anti-pronation tape are robust even after continuous use over a period of 11 days.

Thesis (Ph.D.) -- McMaster University, 1999. / Includes bibliographical references (leaves 154-160). Also available via World Wide Web.