Swallowing problems, and the often-associated sequelae including pneumonia, malnutrition, and dehydration are common, potentially life-threatening conditions suffered by many elderly individuals. The combination of cognitive, physical, and sensory impairments commonly seen in individuals with dementia and following stroke often results in eating needs going unmet, leading to increased morbidity and premature mortality. The functional limitations of many of these individuals frequently result in decreased mealtime independence and necessitate extensive or total assistance (i.e., dependence) with consuming food and liquids. Despite the implication of increased safety associated with feeding assistance, the influence and potential risk of absent pre-oral cues are unclear, especially in an already taxed system. This study investigated the cooperative relationships between the sequential sensorimotor acts involved in eating and swallowing, focusing on the anticipatory stage, under various sensory-loss conditions. Kinematic data from the lips, jaw, and hand were obtained from 24 healthy younger adults (ages 18-30) and 24 healthy older adults (ages 70-85) under four different conditions: typical self-feeding, typical assisted feeding (i.e., loss of proprioceptive cues), sensory loss self-feeding (i.e., loss of visual cues and degradation of auditory cues), and sensory loss assisted feeding (i.e., loss/degradation of auditory, proprioceptive, and visual cues). During typical self-feeding, all participants began the mouth opening gesture shortly after the onset of hand movement toward the mouth and prior to the onset of oral sensation. However, differences in the timing of anticipatory onset and offset lip movements were observed between older and younger adults and also on the basis of the presence/absence of feeding dependency and sensory loss. Older adults initiated lowering movement earlier than younger adults given the availability of proprioceptive and/or visual cues. In addition to demonstrating earlier lip lowering, during both self-feeding conditions older adults more consistently attended to the timing between lip lowering onset and hand movement onset as compared to both the younger adults and other relative timing pairs. Given the absence of proprioceptive cues (i.e., during assisted feeding), the onset of anticipatory lip movement was delayed. Sensory loss (i.e., loss of visual cues, reduction in auditory cues) alone did not negatively impact the onset of lip movement for either group as compared to typical self-feeding. Conversely, the presence of sensory loss more negatively impacted the offset of lip movement as compared to the absence of proprioception (e.g., the offset of lip movement was later given only visual/auditory loss as compared to assisted feeding). The presence of both feeding dependence and sensory loss had the greatest negative impact on the timing of both the onset and offset of anticipatory lip movement. These findings suggest that deglutition should be considered as beginning prior to the onset of oral sensation and highlight the necessity of better understanding the role that pre-oral, or anticipatory, sensorimotor information may play in the overall eating and deglutitory process. As older adults consistently demonstrated a "compensatory advantage" via earlier and less variable movement onset given the availability of proprioceptive and/or visual cues, continued investigation into these age-related differences is important. This study provides a first step in clarifying the relationship between these pre-oral cues and anticipatory oral posturing during eating and swallowing, allowing for a better understanding of the potential for increased risk assisted feeding recommendations may elicit. However, the differences observed between older and younger adults, particularly under conditions of sensory loss, may be further exacerbated in a taxed system, potentially increasing risk for various patient populations.

The very short-term resistance training (VST) model, utilizing only 2-3 training sessions, has been used to examine early phase skeletal muscle, neural, and performance adaptations. The VST model has previously been used to examine these early phase adaptations in bilateral and unilateral, isometric, isokinetic, and dynamic muscle actions in the limbs of the upper- and lower-body. The bilateral deficit (BLD) is a phenomenon in which the sum of the forces produced unilaterally is greater than the force produced bilaterally during maximal contraction of the limbs. The appearance of a bilateral deficit has been be related to various factors; including training status and mode of training (bilateral versus reciprocal muscle actions). No previous study, however, has examined the effects of VST on the BLD. The VST model has potential implications for examining acute changes in strength and neuromuscular responses of the trained muscles. These adaptations, however, may be specific to unilateral or bilateral training. Therefore, the purposes of this study were to: 1) examine one repetition maximum (1RM) strength and neuromuscular responses (EMG AMP, EMG MPF, MMG AMP, MMG MPF) during the measurement of bilateral and unilateral leg extension exercise before and after dynamic constant external resistance (DCER) VST; 2) examine the magnitude of the BLD; 3) examine the effect of bilateral versus unilateral training on the BLD; and 4) use the neuromuscular responses measured bilaterally and unilaterally to infer about the motor unit activation strategies that may underlie the BLD and changes in 1RM strength. Twenty-four (14 males, 10 females) subjects (mean ± SD age: 23.0 ± 3.2 yr; height: 174.7 ± 8.5 cm; body mass: 75.4 ± 14.1 kg) with no resistance training experience within the last three months were randomly assigned to either the bilateral (BL) training group or the unilateral (UL) training group. The subjects completed a total of seven visits, consisting of a familiarization, pre-test visit, three training visits, and one post-test visit. The pre-test visit was used to record the subject’s electromyographic (EMG) and mechanomyographic (MMG) responses from the right and left vastus lateralis (VL) during bilateral and unilateral seated maximum isometric voluntary contractions (MVIC) and 1RM. Visits four through six were the training sessions, with each subject preforming 5 sets of 6 repetitions utilizing 65% of the 1RM for resistance where the BL group trained both limbs (right and left) at the same time and the UL group trained both limbs separately. Visit seven was the post-test and the same testing procedures as the pre-test visit were followed. Statistical analyses consisted of four-way and three-way mixed model ANOVAs, with follow up three-, two- and one-way repeated measures and/or mixed model ANOVAs, Bonferroni corrected paired, and independent samples t-tests when appropriate. An alpha level of P ≤ 0.05 was considered statistically significant for all ANOVAs. The BL group demonstrated a significant increase (p = 0.006; 6.8%) in BL1RM pre- to post-test, but no change in unilateral summed (US1RM = right + left limb; p = 0.726) 1RM strength. The UL group demonstrated an 8.7% increase in BL strength collapsed across testing mode (BL1RM and US1RM) (p = 0.0001) and UL strength (p = 0.0001) collapsed across limb (UL left + UL right/2) from pre- to post-test. The BL group had a significant (p = 0.001) increase in the BI (indicating a decrease in the BLD) from pre- to post-test, but there was no significant change for the UL group. The BL group demonstrated a significant (p = 0.029) decrease in the EMG mean power frequency (MPF) measurement pre- to post-test, however the UL group showed no change. The unilateral movement, collapsed across limbs (unilateral left and unilateral right) also showed a significant (p = 0.022) decrease in the MMG MPF measurement pre- to post-test, whereas the BL movement showed no change. These findings indicated that BL and UL DCER training increased strength after 3 training sessions. The bilateral DCER training resulted in bilateral, but not unilateral strength increases and unilateral DCER training resulting in both bilateral and unilateral strength increases. However, bilateral training was the only mode of training that significantly decreased the BLD.

Musculoskeletal Injuries are the most common cause of severe long-term pain and physical disability. Push-Ups and Pull-Ups are effective dynamic exercises that mimic high level function activities, such as those used in the military. The model developed allows for researchers to analyze the forces and moments associated with the shoulder, elbow and wrist, to further assess function in military personnel, athletes and the active population. The model also follows the guidelines set forth by the International Society of Biomechanics (ISB).

Since the introduction of the American Academy of Pediatrics Back to Sleep Campaign infants have not met the recommendation to “incorporate supervised, awake “prone play” in their infant’s daily routine to support motor development and minimize the risk of plagiocephaly”. Interventions are needed to increase infants’ tolerance for prone position and prone playtime to reduce the risk of plagiocephaly and motor delays. Associative learning is the ability to understand causal relationship between events. Operant conditioning is a form of associative learning that occurs by associating a behavior with positive or negative consequences. Operant conditions has been utilized to encourage behaviors such as kicking, reaching and sucking in infants by associating these behaviors with positive reinforcement. This dissertation is a compilation of three papers that each represent a study used to investigate a potential play based interventions to encourage prone motor skills in infants. The first paper describes a series of experiment used to develop the Prone Play Activity Center (PPAC) and experimental protocols used in the other studies. The purpose of the second study was to determine the feasibility of a clinical trial comparing usual care (low tech) to a high-tech intervention based on the principles of operant conditioning to increase tolerance for prone and improve prone motor skills. Ten infants participated in the study where parents of infants in the high tech intervention group (n=5) used the PPAC for 3 weeks to practice prone play. Findings from this study suggested the proposed intervention is feasible with some modifications for a future large-scale clinical trial. The purpose of the third study evaluated the ability of 3-6 months old infants to demonstrate AL in prone and remember the association learned a day later. Findings from this study suggested that a majority of infants demonstrated AL in prone with poor retention of the association, 24 hours later. Taken together these 3 papers provide preliminary evidence that a clinical trial of an intervention is feasible and that associative learning could be used to reinforce specific prone motor behaviors in the majority of infants.

This research study examined motor control and procedural learning abilities in the oral and manual motor systems of adults who stutter, using people with Parkinson's disease, and age-matched controls as comparison groups. Participants in this study were asked to track a moving target on a computer screen with their jaw and with their dominant hand. Specifically, we compared their tracking accuracy for predictable and unpredictable signals. Procedural learning (defined as increased accuracy over time) was assessed by examining changes in tracking accuracy within a single tracking trial and between consecutive tracking trials of the same predictable condition. There were two main findings in this study related to tracking accuracy and procedural learning in people who stutter (PWS) and age-matched controls (CPWS). First, our analyses revealed that there was no significant difference between PWS and CPWS in the accuracy of tracking of either predictable or unpredictable conditions for either the hand or the jaw, although a trend was observed in which PWS performed more poorly in both for decreased accuracy. Second, both PWS and CPWS showed evidence of procedural learning to the same extent. There were two main findings in this study related to tracking accuracy and procedural learning in people who have Parkinson's disease (PPD) and age-matched controls (CPPD). First, tracking accuracy analyses revealed that PPD performed significantly more poorly than CPPD during jaw tracking of predictable conditions, but they were not significantly different from CPPD in jaw tracking of unpredictable conditions. During hand tracking PPD differed significantly from CPPD in tracking of both predictable and unpredictable conditions for their less accurate performance. Second, there was no significant difference between the two groups in the extent of procedural learning during jaw tracking. However, during hand tracking the PPD group improved less with time than the CPPD, suggesting that the PPD group had reduced procedural learning ability in the manual motor domain. Lastly, age was found to be an important factor determining tracking accuracy in our participants. Younger participants (PWS and CPWS) in the age range of 18-40 years had significantly better accuracy of jaw and hand tracking than the older individuals (PPD and CPPD) in the age range of 57-79 years.

No description available.

An examination of throwing was performed in a controlled environment with the aim of identifying the control and order parameters of throwing as proposed by dynamic pattern theory. A pilot study was conducted to test the possibility that the mass of a ball, the distance thrown and the size of targets were the control parameters. Based upon the results of the pilot study, only the distance was manipulated as an independent variable in the principal study.Three-dimensional motion was recorded using three video cameras in the motion analysis laboratory and later analysed using the Peak motion analysis system (software version 5.0, 1992). Sixteen right handed adult females, aged 18 - 35 years, volunteered to participate in the principal study. Subjects were seated with their trunks secured to the back support of an adjustable chair. Ten different targets (0.6 to 6.91 m) were labelled on the floor in front of the subjects. A large area for each target was defined so that the throwing skill of subjects could be ignored as a factor in the research design. Subjects were asked to throw a 0.5 kg ball to ten different distances using their own styles which allowed them to change the pattern of throwing as the distance thrown increased.All 16 subjects selected either an overarm or an underarm throw or employed both patterns. No subject used other patterns of throwing. At the shortest distance, a greater number of subjects selected an underarm throw. As the distance thrown increased, some subjects switched to the overarm throw. At the distance of 3.36 m, there were eight subjects (50%) using each style of throwing. Alteration of the throwing pattern mainly occurred from the underarm to the overarm throw. The results suggest that the distance thrown may be one of the control parameters in the throwing movement.Furthermore, the presence of both throwing patterns for all distances ++ / thrown suggests the presence of a multiple stable state in throwing motions. Trajectories of movement become more uniform as the distance thrown increased. Variability was greatest when subjects threw to the shortest distance for both patterns. These results imply that as the distance thrown increased the stability of both throwing patterns increased. Moreover, these results also imply a phase transition within each throwing pattern, in addition to the phase shift between the pattern of throwing.No result could directly illustrate the period of the transition. This may be due to the fact that phase transition in a multistable system is the result of an external force which drives the system from one state to another. Alteration of the pattern does not occur as a result of loss of the stability of the previous state. Furthermore, the presence of both throwing patterns for all distances thrown suggests the presence of a multiple stable state in throwing motions. Trajectories of movement become more uniform as the distance thrown increased. Variability was greatest when subjects threw to the shortest distance for both patterns. These results imply that as the distance thrown increased the stability of both throwing patterns increased. Moreover, these results also imply a phase transition within each throwing pattern, in addition to the phase shift between the pattern of throwing. No result could directly illustrate the period of the transition. This may be due to the fact that phase transition in a multistable system is the result of an external force which drives the system from one state to another. Alteration of the pattern does not occur as a result of loss of the stability of the previous state. However, some of the results such as the hysteresis graph presented indirect evidence, which could imply a phase shift between throwing patterns. In addition the higher ++ / degrees of joint angle recruitment in the overarm throw suggest that the stability of the system may be better maintained in the overarm throw than in the underarm throw.Alteration of the sub-styles of throwing within the same throwing pattern seemed to occur in between the shortest and the longest distances thrown. Many of the results supported this concept, for example, data related to the relative timing, the total ROM, the releasing joint angles, the trajectories of the movement, the phase plane plots, the angle-angle plots, and relative phase. However, the presence of sub-styles in the underarm throw was not as obvious as was the case for the overarm throw.In conclusion, the changes in motor behaviour during throwing as the distance thrown increased as examined in the present study can be explained by dynamic pattern theory in some aspects. However, further investigation of the stability of the patterns and energy utilisation necessary for the execution of the underarm and overarm throw are essential to determine the most suitable order parameter and to confirm the proposed control parameter (distance thrown) identified.

The relationship between feeding development and early speech production has received increasing interest over the past 30 years. If a relationship between the motor control systems for feeding and communication is present, it could have implications for the early identification of communication deficits in children. Theoretical support exists for a relationship between the feeding and speech motor systems based on evolutionary theory (Blanchard, 1963), and anatomical similarities in oral motor function (Morris, 1985, 1990, 1991, 1998). However, the existence of a causal relationship between early feeding and communication development remains uncertain due to a lack of empirical research. A model proposed by Carpendale and Lewis (2004) encompasses the triadic interaction between the environment, maternal factors, and infant factors, which can influence both feeding and communication development. Clinical feeding assessments typically employed by clinicians and researchers are most often carried out with observational checklists. Data reflecting the theoretical foundation, validity, and reliability for these tools are limited. Observation tools assess specific aspects of feeding and oral motor control from a modular perspective, without regard for the infant’s total feeding system. Rogers and Arvedson (2005) highlighted the need for a single standardised assessment tool to assess infant feeding descriptively and objectively. The primary aim of the project was to determine whether the same motor control mechanisms are utilised for oral feeding and communication. The first stage of the study involved the development of a theoretically informed assessment protocols to document systematically the development of feeding skills from birth, the Feeding Assessment Observation (FAO) and the Feeding Assessment Questionnaire (FAQ). / The assessment protocol was piloted on 10 term and 10 preterm infants at 1 to 2 weeks, 4, 8 and 12 months corrected age (CA) for preterm infants and chronological age for term infants. The second stage of the project examined the progression of feeding and communication development in a group of term and preterm infants over a 12 month period. The progression of 8 preterm and 7 term infants was observed at 1-2 weeks, 4, 8 and 12 months CA and chronological age for term infants. The mean gestational age for preterm infants was 30 weeks, 6 days (SD = 6.8 days), and term infants was 39 weeks, 5 days (SD = 9.4 days). Assessment of the infants’ feeding and communication skills, environmental and maternal influences was conducted using the initial questionnaire, Feeding Assessment Observation (FAO), Feeding Assessment Questionnaire (FAQ), Home Screening Questionnaire (HSQ), Receptive Expressive Emergent Language Scale, second edition (REEL-2), and the infant-toddler checklist of the Communication and Symbolic Behavior Scales Developmental Profile (CSBS-DP), to determine the nature and impact of environmental and social factors on feeding and/or communication development. Preliminary reliability testing of the FAO was conducted. Sixty seven percent (10/15) of observation items achieved greater than 90% inter-observer agreement. There was no significant difference in feeding and communication development between term and preterm infants. The negative linear trend for the development of feeding efficiency on liquids for infants was opposed to the positive linear trend for communication development. Infant feeding efficiency on solids showed parallel positive linear developmental trends with communication development. / Comprehensive data were collected on influencing factors from infant, maternal and environmental domains during the initial assessment, and the 4, 8 and 12 month CA developmental reviews. The data revealed significant differences between the term and preterm groups for infant and environmental factors, but no significant differences were found for maternal influences. The study provided some support for the hypothesis of integrative motor control and co-development of feeding and communication. The prediction that infant, maternal, and environmental factors would significantly influence feeding and communication development was not supported. In addition, there was no difference in the impact of influencing factors for the term and preterm groups. The feeding and communication skills of preterm infants developed at corrected age levels, and were not significantly slower than term infants. Furthermore, predicted delays in feeding development were not associated with concomitant delays in communication development for term and preterm infants. Further investigation of the subsequent communication development of infants with definitive feeding difficulties and with a larger sample is suggested.

<p>This thesis work contains a litterature study about electrical motors in general and how PWM-patterns for brushless DC-motors can be made. A suitable method has been implemented as a simulation model in VHDL. A simulation model of a brushless DC-motor which describes the phasecurrents, torque and angular velocity has also been made. The motor model made simulations easier for the complete PWM-system. </p><p>The design was synthesised and tested with a prototypeboard including a SPARTAN II FPGA. In order to test the design, a powerstage and a motor was included. The tests showed that the design was working as expected according to the previous simulations. </p><p>A study about an alternative way to control a brushless DC-motor has also been made. This alternative is best suited when the generated back-EMK for the motor is sinusoidal. A simulation model for a part of a system like this has been made, and it has been synthesised in order to examine if it is possible to implement using a FPGA availible today.</p>

<p>This thesis presents, analyzes and suggests solutions to the dead-lock problem of the sensorless variable speed drive NFO Sinus. Friction, measurement, parameter estimation and quantization effects are believed possible origins of this problem and is hence studied. A short introduction to ¯eld oriented control of the asynchronous AC motor and the NFO Control strategy is also included.</p><p>The report is published at LiTH as ISRN LiTH-ISY-EX--06/3945--SE and at LTH under ISRN LUTFD2/TFRT--5780--SE.</p>