L. Oddsson - Academia.edu (original) (raw)

Papers by L. Oddsson

Archives of Physical Medicine and Rehabilitation, 2018

demographics, injury type, days until admission, treatment duration, and functional ability at ad... more demographics, injury type, days until admission, treatment duration, and functional ability at admission. Improvement on the MPAI-4 Ability (c 2 Z10.3, pZ.001, ORZ1.05) and Participation subscales (c 2 Z48.2, p<.001, ORZ1.12) significantly predicted RTW, while the Adjustment scale did not (pZ.566), despite identical median improvement (TZ13). In those that RTW, average discharge MPAI-4 subscale scores fell in the mild impairment range (TZ30-40). Fewer days since injury, milder functional deficits at admission, male gender, and a shorter rehabilitation course also predicted RTW (p's<.05), while age at injury, race, education, and injury type did not (p's>.05). Conclusions: The likelihood of RTW increases as a patients' physical and cognitive functioning improves, and as participation in social, recreational, and community-based activities increase. Clinicians can potentially use MPAI-4 Participation and Ability subscale items to guide interventions that improve RTW outcomes. Author(s) Disclosures: The author(s) have no conflicts of interest to disclose.

Age and Ageing, 2007

Objectives to assess the use of the Voluntary Step Execution Test to identify fallers. Design cro... more Objectives to assess the use of the Voluntary Step Execution Test to identify fallers. Design cross-sectional retrospective. Setting two self-care, residential facilities. Participants a total of 100 healthy old volunteers (mean age = 78.4 ± 5.7). Measurements the study investigated the use of the Voluntary Step Execution Test to identify fallers under single and dual-task conditions. Berg Balance Test (BBS) and Timed Get Up and Go (TUG) were used to assess balance and gait function. Results there were no significant differences found between fallers and non-fallers in BBS and TUG (50.5 ± 4.6 versus 52.5 ± 3.4 and 9.4 ± 3.4 versus 7.98 ± 2.3 respectively). There were no statistically significant differences between non-fallers and fallers across all step execution parameters under the single-task condition. However, adding cognitive load to the Voluntary Step Execution Test revealed statistically significant increases in duration of the preparatory phase, swing time and the time to foot-contact (P = 0.035; P = 0.033 and P = 0.037, respectively). Based on the coefficients of the logistic regression model participants with dual-task step execution times of ≥1,100 ms had five times the risk of falling than participants with execution times of <1,100 ms. Conclusions the study provides evidence that a simple, safe measure of step execution under dual-task conditions can identify elderly individuals at risk for falls.

signal) and 5 control (no stimulation) trials. During the trials, subjects stood in a relaxed, up... more signal) and 5 control (no stimulation) trials. During the trials, subjects stood in a relaxed, upright position with their head facing forward. Postural sway was evaluated by using a force platform to measure the displacements of the center of pressure (COP) under each subject's feet. Cross-spectral measures were used to quantify the relationship between the applied stimulus and the resulting COP time series. We found significant coherency between the stochastic vestibular stimulation signal and the resulting mediolateral COP time series in the majority of trials in 8 of the 9 subjects tested. The coherency results for each stimulation signal were highly reproducible from trial to trial, and the highest degree of coherency was found for the 1--2 Hz stochastic vestibular stimulation signal. In general, for the 9 subjects tested, we did not find consistent significant coherency between the stochastic vestibular stimulation signals and the anteroposterior COP time series. This wor...

The predominantly fast twitch gastrocnemius and the slower soleus muscle act in synergy around th... more The predominantly fast twitch gastrocnemius and the slower soleus muscle act in synergy around the ankle joint. Earlier studies have demonstrated the preferential involvement of soleus in postural tasks whereas gastrocnemius is more activated when demands of force and speed of contraction increase. The aim of this study was to relate mechanical characteristics and fatigue properties of the triceps surae muscles to the performance of jumping in subjects involved in sports with different demands on endurance andlor power. Eight physically active males with mixed background in sports participated in the study. Subjects performed maximal Counter Movement Jumps (CMJ) and maximal hopping on a force plate for 80 s with the instruction to maintain a minimal ground contact time. Electromyographic activity (EMG) was recorded with surface electrodes from soleus and medial head of gastrocnemius. Maximal twitch responses were recorded with the right foot tightly strapped to a mechanical device i...

Journal of rehabilitation research and development, 1997

Spectral parameters of the surface electromyographic (EMG) signal from lumbar back muscles assess... more Spectral parameters of the surface electromyographic (EMG) signal from lumbar back muscles assessed during a fatiguing isometric contraction can be used to classify different categories of low back pain (LBP) subjects and control subjects without LBP. In the test protocol currently used at the NeuroMuscular Research Center at Boston University, subjects contract their back muscles at 80% of their maximal voluntary contraction (MVC) force. This fatigue-based protocol has been successfully applied to persons with subacute or chronic LBP; those in acute pain, however, have not been included because of their inability to perform a maximal exertion. In this paper we will examine the force sensitivity of the currently used EMG parameters and also give an overview of some of our efforts to develop new test procedures. Our goal is to develop force-insensitive surface EMG parameters that can be used for classification purposes in populations of subjects who develop low trunk extension forces...

The ability to jump is important in several different sports, Therefore, an increased knowledge a... more The ability to jump is important in several different sports, Therefore, an increased knowledge about factors limiting vertical jumping ability is of interest for both coaches and athletes. A common experience among coaches is that up to a certain degree almost any type of training program will increase the vertical jumping capacity, However, an increased performance level of the athlete will require more specific and individually adapted training methods. The problem is then to know which type of training is best suited for each individual athlete. The maximal vertical jumping height is influenced by a number of biomechanical and physiological factors. Ultimately, the jumping height is determined by the vertical velocity of the centre of gravity at take-off. This velocity depends on the mass of the subject and the linear impulse which is the result of the upward acceleration of the different body segments involved in the jumping action. The segmental accelerations are, in turn, cau...

Locomotion requires integration of visual, vestibular, and somatosensory information to produce t... more Locomotion requires integration of visual, vestibular, and somatosensory information to produce the appropriate motor output to control movement. The degree to which these sensory inputs are weighted and reorganized in discordant sensory environments varies by individual and may be predictive of the ability to adapt to novel environments. The goals of this project are to: 1) develop a set of predictive measures capable of identifying individual differences in sensorimotor adaptability, and 2) use this information to inform the design of training countermeasures designed to enhance the ability of astronauts to adapt to gravitational transitions improving balance and locomotor performance after a Mars landing and enhancing egress capability after a landing on Earth.

International Journal of Sports Medicine, 2015

The study evaluated the effect of 4 weeks of combined resistance-balance training and resistance ... more The study evaluated the effect of 4 weeks of combined resistance-balance training and resistance training alone in a 90° tilted environment on muscle power. Two groups of healthy young subjects performed leg extensions while in a supine position, either on a firm surface along a linear track or on an unstable surface requiring mediolateral balancing movements. Power and force during squats were measured at isokinetic velocities of 10 and 35 deg/s. Results showed significantly greater gains in peak force (44.1%; F(1,21)=8.876, p=0.026), mean force (58.6%; F(1,21)=16.136, p=0.013), peak power (58.7%; F(1,21)=18.754, p=0.009), and mean power (59.2%; F(1,21)=23.114, p=0.007) at the velocity of 35 deg/s after stable than unstable resistance training. However, there were no significant between-groups differences in pre-post training gains in peak force (10.4%; F(1,21)=1.965, p=0.74), mean force (10.3%; F(1,21)=1.889, p=0.80), peak power (12.9%; F(1,21)=2.980, p=0.49), and mean power (19.1%; F(1,21)=3.454, p=0.36) during squats at the velocity of 10 deg/s. Resistance exercises under stable conditions performed in a 90° tilted environment are more effective in the improvement of high velocity muscle power than their use in combination with balance exercises. Such training may be applicable in pre- and in-flight exercise regimens for astronauts and in functional rehabilitation of bed-ridden patients.

Physiotherapy, 2015

Results: There were no significant differences between groups for muscle recruitment, pain or dis... more Results: There were no significant differences between groups for muscle recruitment, pain or disability at 2month follow-up (P > 0.1). Global improvement at 2-months demonstrated greater treatment effect for MDT compared to motor control exercises with a significant between group difference of 0.78 (P < 0.03 95%CI). Baseline and follow-up scores for MDT were −0.82 (SD 3.0) and 3.5 (SD 1.0); motor control exercises scores were −0.86 (SD 2.4) and 2.7 (SD 1.7). Conclusion(s): Both approaches offer similar effects for muscle recruitment and clinical outcomes in a LBP population classified with a derangement. Change in trunk muscle recruitment appears unrelated to motor control exercises in this group of patients. Between group differences for global improvement scores suggest a greater sense of clinical improvement when treated with MDT for this population; however, it is unclear if the same effect is present in the long-term. Implications: As results for this cohort are similar for muscle recruitment, pain and disability irrespective of whether patients receive MDT or motor control exercises, either approach could be recommended, although greater global improvements suggest MDT may be a preferable choice for the short term.

Journal of vestibular research : equilibrium & orientation

We compared the mediolateral (M/L) responses to perturbations during locomotion of vestibulopathi... more We compared the mediolateral (M/L) responses to perturbations during locomotion of vestibulopathic (VP) subjects to those of controls. Eight subjects with unilateral vestibular loss (100% Reduced Vestibular Response from the caloric test) resulting from surgery for vestibular schwannoma and 11 controls were selected for this study. Despite their known vestibulopathy, all VP subjects scored within the normal range on computerized dynamic posturography Sensory Organization Tests. During gait, subjects were given surface perturbations of the right support-phase foot in two possible directions (forward-right and backward-left) at two possible magnitudes (5 and 10 cm) that were randomly mixed with trials having no perturbations. M/L stability was quantified by estimating the length of the M/L moment arm between the support foot and the trunk, and the M/L accelerations of the sternum and the head. The VP group had greater changes (p < 0.05) in their moment arm responses compared to con...

Physical therapy, 1998

The purpose of this article is to provide an overview of research to develop surface electromyogr... more The purpose of this article is to provide an overview of research to develop surface electromyographic (EMG) measurements for classification of paraspinal muscle impairments in persons with low back pain (LBP). The process of developing laboratory and clinically based protocols is described. Results of studies to evaluate the reliability of these measurements and their relationships with impairments and function are discussed. Research efforts to incorporate EMG spectral measurements, such as the median frequency, into a classification system to identify different types of muscle impairments are documented. Discriminant functions have been calculated based on case-control studies to identify 2 kinds of LBP impairments from constant-force isometric tasks: (1) excessive fatigue due to muscle deconditioning and (2) inhibition of muscle activation secondary to pain or pain-related behaviors. New areas of investigation designed to improve the classification accuracy of such functions usi...

Journal of rehabilitation research and development, 1997

Spectral parameters of the surface electromyographic (EMG) signal from lumbar back muscles assess... more Spectral parameters of the surface electromyographic (EMG) signal from lumbar back muscles assessed during a fatiguing isometric contraction can be used to classify different categories of low back pain (LBP) subjects and control subjects without LBP. In the test protocol currently used at the NeuroMuscular Research Center at Boston University, subjects contract their back muscles at 80% of their maximal voluntary contraction (MVC) force. This fatigue-based protocol has been successfully applied to persons with subacute or chronic LBP; those in acute pain, however, have not been included because of their inability to perform a maximal exertion. In this paper we will examine the force sensitivity of the currently used EMG parameters and also give an overview of some of our efforts to develop new test procedures. Our goal is to develop force-insensitive surface EMG parameters that can be used for classification purposes in populations of subjects who develop low trunk extension forces...

2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2012

Sensory substitution devices can provide body orientation and somatosensory information through v... more Sensory substitution devices can provide body orientation and somatosensory information through vibrotactile feedback. This pilot study compares the effects of two vibrotactile feedback devices during a locomotor task using similar groups of elder subjects.

Journal of Medical Devices, 2009

Interdisciplinary settings have been highlighted for creative user-close development of products ... more Interdisciplinary settings have been highlighted for creative user-close development of products and services. Similarly, user involvement in the actual design process has been presented as a way to make attractive products that will earn market shares. But will an interdisciplinary setting in itself generate the beneficial spin-offs we expect? Will including the end-user on the development team ensure better products that are more successful on the market? A study has been set up to create a work model for Clinical Innovation Teams (CIT) at the Sister Kenny Research Center in Minneapolis, MN, to facilitate the research and development process, and provide guidance to work in a creative and innovative way around rehabilitation technology development. The CITs consist of clinicians, such as nurses, occupational therapists, physical therapists, physicians, engineers and engineering students, and in some cases patients. The CITs combine the interdisciplinary setting and end-user involv...

Azusa Pacific University, Azusa, CA. Astronauts experience sensorimotor disturbances during the i... more Azusa Pacific University, Azusa, CA. Astronauts experience sensorimotor disturbances during the initial exposure to microgravity and during the re-adapation phase following a return to an earth-gravitational environment. These alterations may disrupt the ability to perform mission critical functional tasks requiring ambulation, manual control and gaze stability. Interestingly, astronauts who return from space flight show substantial differences in their abilities to readapt to a gravitational environment. The ability to predict the manner and degree to which individual astronauts would be affected would improve the effectiveness of countermeasure training programs designed to enhance sensorimotor adaptability. For such an approach to succeed, we must develop predictive measures of sensorimotor adaptability that will allow us to foresee, before actual space flight, which crewmembers are likely to experience the greatest challenges to their adaptive capacities. The goals of this project are to identify and characterize this set of predictive measures that include: 1) behavioral tests to assess sensory bias and adaptability quantified using both strategic and plastic-adaptive responses; 2) imaging to determine individual brain morphological and functional features using structural magnetic resonance imaging (MRI), diffusion tensor imaging, resting state functional connectivity MRI, and sensorimotor adaptation task-related functional brain activation; 3) genotype markers for genetic polymorphisms in Catechol-O-Methyl Transferase, Dopamine Receptor D2, Brain-derived neurotrophic factor and genetic polymorphism of alpha2-adrenergic receptor that play a role in the neural pathways underlying sensorimotor adaptation. We anticipate these predictive measures will be significantly correlated with individual differences in sensorimotor adaptability after long-duration space flight and an analog bed rest environment. We will be conducting a retrospective study leveraging data already collected from relevant ongoing/completed bed rest and space flight studies. These data will be combined with predictor metrics that will be collected prospectively - behavioral, brain imaging and genomic measures; from these returning subjects to build models for predicting post-mission (bed rest - non-astronauts or space flight - astronauts) adaptive capability as manifested in their outcome measures. Comparisons of model performance will allow us to better design and implement sensorimotor adaptability training countermeasures that are customized for each crewmember’s sensory biases, adaptive capacity, brain structure and functional capacities, and genetic predispositions against decrements in post-mission adaptive capability. This ability will allow more efficient use of crew time during training and will optimize training prescriptions for astronauts to ensure expected outcomes.

Scandinavian Journal of Medicine & Science in Sports, 2007

The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis ... more The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis and hip Anderson E, Oddsson L, Grundstrom H, Thorstensson A. The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis and hip.

Neuroscience Letters, 1994

Medicine and Science in Sports and Exercise, 2001

Although low back pain (LBP) is a widespread and disabling health problem, there is a lack of evi... more Although low back pain (LBP) is a widespread and disabling health problem, there is a lack of evidence based medicine with respect to its treatment and rehabilitation. A major reason for this is the poor understanding of the underlying mechanisms of the LBP syndromes. In an attempt to fill this gap, the present review article provides an overview of the sensory-motor control aspects of trunk stabilization and postural control of the trunk, and how they may relate to the evolution of LBP. In particular, the anatomy and physiology of the sensory-motor control mechanisms of the trunk muscles that contribute to general and segmental stability of the lumbar spine will be elucidated. Furthermore, a brief overview of current theories of postural control will be provided with respect to spinal stabilization. Finally, a concept of the pathophysiological changes within the sensory-motor control mechanisms of the lumbar spine in the presence of muscle injury and pain will be presented. The impact of pain and muscle injury on the muscular support for the lumbar motion segment will be discussed along with the deficits in neuromuscular control in LBP patients with decreased segmental lumbar stability.

Archives of Physical Medicine and Rehabilitation, 2018

demographics, injury type, days until admission, treatment duration, and functional ability at ad... more demographics, injury type, days until admission, treatment duration, and functional ability at admission. Improvement on the MPAI-4 Ability (c 2 Z10.3, pZ.001, ORZ1.05) and Participation subscales (c 2 Z48.2, p<.001, ORZ1.12) significantly predicted RTW, while the Adjustment scale did not (pZ.566), despite identical median improvement (TZ13). In those that RTW, average discharge MPAI-4 subscale scores fell in the mild impairment range (TZ30-40). Fewer days since injury, milder functional deficits at admission, male gender, and a shorter rehabilitation course also predicted RTW (p's<.05), while age at injury, race, education, and injury type did not (p's>.05). Conclusions: The likelihood of RTW increases as a patients' physical and cognitive functioning improves, and as participation in social, recreational, and community-based activities increase. Clinicians can potentially use MPAI-4 Participation and Ability subscale items to guide interventions that improve RTW outcomes. Author(s) Disclosures: The author(s) have no conflicts of interest to disclose.

Age and Ageing, 2007

Objectives to assess the use of the Voluntary Step Execution Test to identify fallers. Design cro... more Objectives to assess the use of the Voluntary Step Execution Test to identify fallers. Design cross-sectional retrospective. Setting two self-care, residential facilities. Participants a total of 100 healthy old volunteers (mean age = 78.4 ± 5.7). Measurements the study investigated the use of the Voluntary Step Execution Test to identify fallers under single and dual-task conditions. Berg Balance Test (BBS) and Timed Get Up and Go (TUG) were used to assess balance and gait function. Results there were no significant differences found between fallers and non-fallers in BBS and TUG (50.5 ± 4.6 versus 52.5 ± 3.4 and 9.4 ± 3.4 versus 7.98 ± 2.3 respectively). There were no statistically significant differences between non-fallers and fallers across all step execution parameters under the single-task condition. However, adding cognitive load to the Voluntary Step Execution Test revealed statistically significant increases in duration of the preparatory phase, swing time and the time to foot-contact (P = 0.035; P = 0.033 and P = 0.037, respectively). Based on the coefficients of the logistic regression model participants with dual-task step execution times of ≥1,100 ms had five times the risk of falling than participants with execution times of <1,100 ms. Conclusions the study provides evidence that a simple, safe measure of step execution under dual-task conditions can identify elderly individuals at risk for falls.

signal) and 5 control (no stimulation) trials. During the trials, subjects stood in a relaxed, up... more signal) and 5 control (no stimulation) trials. During the trials, subjects stood in a relaxed, upright position with their head facing forward. Postural sway was evaluated by using a force platform to measure the displacements of the center of pressure (COP) under each subject's feet. Cross-spectral measures were used to quantify the relationship between the applied stimulus and the resulting COP time series. We found significant coherency between the stochastic vestibular stimulation signal and the resulting mediolateral COP time series in the majority of trials in 8 of the 9 subjects tested. The coherency results for each stimulation signal were highly reproducible from trial to trial, and the highest degree of coherency was found for the 1--2 Hz stochastic vestibular stimulation signal. In general, for the 9 subjects tested, we did not find consistent significant coherency between the stochastic vestibular stimulation signals and the anteroposterior COP time series. This wor...

The predominantly fast twitch gastrocnemius and the slower soleus muscle act in synergy around th... more The predominantly fast twitch gastrocnemius and the slower soleus muscle act in synergy around the ankle joint. Earlier studies have demonstrated the preferential involvement of soleus in postural tasks whereas gastrocnemius is more activated when demands of force and speed of contraction increase. The aim of this study was to relate mechanical characteristics and fatigue properties of the triceps surae muscles to the performance of jumping in subjects involved in sports with different demands on endurance andlor power. Eight physically active males with mixed background in sports participated in the study. Subjects performed maximal Counter Movement Jumps (CMJ) and maximal hopping on a force plate for 80 s with the instruction to maintain a minimal ground contact time. Electromyographic activity (EMG) was recorded with surface electrodes from soleus and medial head of gastrocnemius. Maximal twitch responses were recorded with the right foot tightly strapped to a mechanical device i...

Journal of rehabilitation research and development, 1997

Spectral parameters of the surface electromyographic (EMG) signal from lumbar back muscles assess... more Spectral parameters of the surface electromyographic (EMG) signal from lumbar back muscles assessed during a fatiguing isometric contraction can be used to classify different categories of low back pain (LBP) subjects and control subjects without LBP. In the test protocol currently used at the NeuroMuscular Research Center at Boston University, subjects contract their back muscles at 80% of their maximal voluntary contraction (MVC) force. This fatigue-based protocol has been successfully applied to persons with subacute or chronic LBP; those in acute pain, however, have not been included because of their inability to perform a maximal exertion. In this paper we will examine the force sensitivity of the currently used EMG parameters and also give an overview of some of our efforts to develop new test procedures. Our goal is to develop force-insensitive surface EMG parameters that can be used for classification purposes in populations of subjects who develop low trunk extension forces...

The ability to jump is important in several different sports, Therefore, an increased knowledge a... more The ability to jump is important in several different sports, Therefore, an increased knowledge about factors limiting vertical jumping ability is of interest for both coaches and athletes. A common experience among coaches is that up to a certain degree almost any type of training program will increase the vertical jumping capacity, However, an increased performance level of the athlete will require more specific and individually adapted training methods. The problem is then to know which type of training is best suited for each individual athlete. The maximal vertical jumping height is influenced by a number of biomechanical and physiological factors. Ultimately, the jumping height is determined by the vertical velocity of the centre of gravity at take-off. This velocity depends on the mass of the subject and the linear impulse which is the result of the upward acceleration of the different body segments involved in the jumping action. The segmental accelerations are, in turn, cau...

Locomotion requires integration of visual, vestibular, and somatosensory information to produce t... more Locomotion requires integration of visual, vestibular, and somatosensory information to produce the appropriate motor output to control movement. The degree to which these sensory inputs are weighted and reorganized in discordant sensory environments varies by individual and may be predictive of the ability to adapt to novel environments. The goals of this project are to: 1) develop a set of predictive measures capable of identifying individual differences in sensorimotor adaptability, and 2) use this information to inform the design of training countermeasures designed to enhance the ability of astronauts to adapt to gravitational transitions improving balance and locomotor performance after a Mars landing and enhancing egress capability after a landing on Earth.

International Journal of Sports Medicine, 2015

The study evaluated the effect of 4 weeks of combined resistance-balance training and resistance ... more The study evaluated the effect of 4 weeks of combined resistance-balance training and resistance training alone in a 90° tilted environment on muscle power. Two groups of healthy young subjects performed leg extensions while in a supine position, either on a firm surface along a linear track or on an unstable surface requiring mediolateral balancing movements. Power and force during squats were measured at isokinetic velocities of 10 and 35 deg/s. Results showed significantly greater gains in peak force (44.1%; F(1,21)=8.876, p=0.026), mean force (58.6%; F(1,21)=16.136, p=0.013), peak power (58.7%; F(1,21)=18.754, p=0.009), and mean power (59.2%; F(1,21)=23.114, p=0.007) at the velocity of 35 deg/s after stable than unstable resistance training. However, there were no significant between-groups differences in pre-post training gains in peak force (10.4%; F(1,21)=1.965, p=0.74), mean force (10.3%; F(1,21)=1.889, p=0.80), peak power (12.9%; F(1,21)=2.980, p=0.49), and mean power (19.1%; F(1,21)=3.454, p=0.36) during squats at the velocity of 10 deg/s. Resistance exercises under stable conditions performed in a 90° tilted environment are more effective in the improvement of high velocity muscle power than their use in combination with balance exercises. Such training may be applicable in pre- and in-flight exercise regimens for astronauts and in functional rehabilitation of bed-ridden patients.

Physiotherapy, 2015

Results: There were no significant differences between groups for muscle recruitment, pain or dis... more Results: There were no significant differences between groups for muscle recruitment, pain or disability at 2month follow-up (P > 0.1). Global improvement at 2-months demonstrated greater treatment effect for MDT compared to motor control exercises with a significant between group difference of 0.78 (P < 0.03 95%CI). Baseline and follow-up scores for MDT were −0.82 (SD 3.0) and 3.5 (SD 1.0); motor control exercises scores were −0.86 (SD 2.4) and 2.7 (SD 1.7). Conclusion(s): Both approaches offer similar effects for muscle recruitment and clinical outcomes in a LBP population classified with a derangement. Change in trunk muscle recruitment appears unrelated to motor control exercises in this group of patients. Between group differences for global improvement scores suggest a greater sense of clinical improvement when treated with MDT for this population; however, it is unclear if the same effect is present in the long-term. Implications: As results for this cohort are similar for muscle recruitment, pain and disability irrespective of whether patients receive MDT or motor control exercises, either approach could be recommended, although greater global improvements suggest MDT may be a preferable choice for the short term.

Journal of vestibular research : equilibrium & orientation

We compared the mediolateral (M/L) responses to perturbations during locomotion of vestibulopathi... more We compared the mediolateral (M/L) responses to perturbations during locomotion of vestibulopathic (VP) subjects to those of controls. Eight subjects with unilateral vestibular loss (100% Reduced Vestibular Response from the caloric test) resulting from surgery for vestibular schwannoma and 11 controls were selected for this study. Despite their known vestibulopathy, all VP subjects scored within the normal range on computerized dynamic posturography Sensory Organization Tests. During gait, subjects were given surface perturbations of the right support-phase foot in two possible directions (forward-right and backward-left) at two possible magnitudes (5 and 10 cm) that were randomly mixed with trials having no perturbations. M/L stability was quantified by estimating the length of the M/L moment arm between the support foot and the trunk, and the M/L accelerations of the sternum and the head. The VP group had greater changes (p < 0.05) in their moment arm responses compared to con...

Physical therapy, 1998

The purpose of this article is to provide an overview of research to develop surface electromyogr... more The purpose of this article is to provide an overview of research to develop surface electromyographic (EMG) measurements for classification of paraspinal muscle impairments in persons with low back pain (LBP). The process of developing laboratory and clinically based protocols is described. Results of studies to evaluate the reliability of these measurements and their relationships with impairments and function are discussed. Research efforts to incorporate EMG spectral measurements, such as the median frequency, into a classification system to identify different types of muscle impairments are documented. Discriminant functions have been calculated based on case-control studies to identify 2 kinds of LBP impairments from constant-force isometric tasks: (1) excessive fatigue due to muscle deconditioning and (2) inhibition of muscle activation secondary to pain or pain-related behaviors. New areas of investigation designed to improve the classification accuracy of such functions usi...

Journal of rehabilitation research and development, 1997

Spectral parameters of the surface electromyographic (EMG) signal from lumbar back muscles assess... more Spectral parameters of the surface electromyographic (EMG) signal from lumbar back muscles assessed during a fatiguing isometric contraction can be used to classify different categories of low back pain (LBP) subjects and control subjects without LBP. In the test protocol currently used at the NeuroMuscular Research Center at Boston University, subjects contract their back muscles at 80% of their maximal voluntary contraction (MVC) force. This fatigue-based protocol has been successfully applied to persons with subacute or chronic LBP; those in acute pain, however, have not been included because of their inability to perform a maximal exertion. In this paper we will examine the force sensitivity of the currently used EMG parameters and also give an overview of some of our efforts to develop new test procedures. Our goal is to develop force-insensitive surface EMG parameters that can be used for classification purposes in populations of subjects who develop low trunk extension forces...

2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2012

Sensory substitution devices can provide body orientation and somatosensory information through v... more Sensory substitution devices can provide body orientation and somatosensory information through vibrotactile feedback. This pilot study compares the effects of two vibrotactile feedback devices during a locomotor task using similar groups of elder subjects.

Journal of Medical Devices, 2009

Interdisciplinary settings have been highlighted for creative user-close development of products ... more Interdisciplinary settings have been highlighted for creative user-close development of products and services. Similarly, user involvement in the actual design process has been presented as a way to make attractive products that will earn market shares. But will an interdisciplinary setting in itself generate the beneficial spin-offs we expect? Will including the end-user on the development team ensure better products that are more successful on the market? A study has been set up to create a work model for Clinical Innovation Teams (CIT) at the Sister Kenny Research Center in Minneapolis, MN, to facilitate the research and development process, and provide guidance to work in a creative and innovative way around rehabilitation technology development. The CITs consist of clinicians, such as nurses, occupational therapists, physical therapists, physicians, engineers and engineering students, and in some cases patients. The CITs combine the interdisciplinary setting and end-user involv...

Azusa Pacific University, Azusa, CA. Astronauts experience sensorimotor disturbances during the i... more Azusa Pacific University, Azusa, CA. Astronauts experience sensorimotor disturbances during the initial exposure to microgravity and during the re-adapation phase following a return to an earth-gravitational environment. These alterations may disrupt the ability to perform mission critical functional tasks requiring ambulation, manual control and gaze stability. Interestingly, astronauts who return from space flight show substantial differences in their abilities to readapt to a gravitational environment. The ability to predict the manner and degree to which individual astronauts would be affected would improve the effectiveness of countermeasure training programs designed to enhance sensorimotor adaptability. For such an approach to succeed, we must develop predictive measures of sensorimotor adaptability that will allow us to foresee, before actual space flight, which crewmembers are likely to experience the greatest challenges to their adaptive capacities. The goals of this project are to identify and characterize this set of predictive measures that include: 1) behavioral tests to assess sensory bias and adaptability quantified using both strategic and plastic-adaptive responses; 2) imaging to determine individual brain morphological and functional features using structural magnetic resonance imaging (MRI), diffusion tensor imaging, resting state functional connectivity MRI, and sensorimotor adaptation task-related functional brain activation; 3) genotype markers for genetic polymorphisms in Catechol-O-Methyl Transferase, Dopamine Receptor D2, Brain-derived neurotrophic factor and genetic polymorphism of alpha2-adrenergic receptor that play a role in the neural pathways underlying sensorimotor adaptation. We anticipate these predictive measures will be significantly correlated with individual differences in sensorimotor adaptability after long-duration space flight and an analog bed rest environment. We will be conducting a retrospective study leveraging data already collected from relevant ongoing/completed bed rest and space flight studies. These data will be combined with predictor metrics that will be collected prospectively - behavioral, brain imaging and genomic measures; from these returning subjects to build models for predicting post-mission (bed rest - non-astronauts or space flight - astronauts) adaptive capability as manifested in their outcome measures. Comparisons of model performance will allow us to better design and implement sensorimotor adaptability training countermeasures that are customized for each crewmember’s sensory biases, adaptive capacity, brain structure and functional capacities, and genetic predispositions against decrements in post-mission adaptive capability. This ability will allow more efficient use of crew time during training and will optimize training prescriptions for astronauts to ensure expected outcomes.

Scandinavian Journal of Medicine & Science in Sports, 2007

The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis ... more The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis and hip Anderson E, Oddsson L, Grundstrom H, Thorstensson A. The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis and hip.

Neuroscience Letters, 1994

Medicine and Science in Sports and Exercise, 2001

Although low back pain (LBP) is a widespread and disabling health problem, there is a lack of evi... more Although low back pain (LBP) is a widespread and disabling health problem, there is a lack of evidence based medicine with respect to its treatment and rehabilitation. A major reason for this is the poor understanding of the underlying mechanisms of the LBP syndromes. In an attempt to fill this gap, the present review article provides an overview of the sensory-motor control aspects of trunk stabilization and postural control of the trunk, and how they may relate to the evolution of LBP. In particular, the anatomy and physiology of the sensory-motor control mechanisms of the trunk muscles that contribute to general and segmental stability of the lumbar spine will be elucidated. Furthermore, a brief overview of current theories of postural control will be provided with respect to spinal stabilization. Finally, a concept of the pathophysiological changes within the sensory-motor control mechanisms of the lumbar spine in the presence of muscle injury and pain will be presented. The impact of pain and muscle injury on the muscular support for the lumbar motion segment will be discussed along with the deficits in neuromuscular control in LBP patients with decreased segmental lumbar stability.