The Impact of Anterior Cruciate Ligament Reconstructive Surgery on Neuromotor Function

The purpose of this dissertation was to examine the systemic neuromechanical implications in individuals who have had an ACL reconstruction (ACLR) compared to healthy controls. The specific aims addressed were to: 1) examine differences in inter-limb coordination during walking at different speeds, 2) examine differences in trunk, neck and head acceleration during gait, and 3) investigate whether the reaction time responses assessed during stepping are negatively affected by ACLR. The findings of study 1 revealed that maximal coordination stability was achieved when walking at the person’s preferred gait speed. However, individuals with a previous ACLR exhibited reduced coordination stability between the knees, indicative of decreased inter-limb coupling. Further, individuals within the ACLR group who deviated the most from anti-phase coordination during walking also demonstrated lower coordination stability. These findings could contribute to the secondary issues related to ACL damage. Study two examined differences in upper body accelerations during gait, revealing that the ACLR group had a diminished capacity to attenuate gait-related oscillations from the trunk to the head. Further, the vertical acceleration signals for the ACLR individuals were more complex, indicating that they had a reduced ability to optimally accelerations during walking. These results demonstrate the impact of ACL damage is not localized but is more systemic and can negatively impact postural control. The third study assessed how ACLR would impact of general neuromotor function and stepping reaction times. The findings revealed that ACLR individuals had slower reaction times during stepping compared to healthy controls. In contrast to the slowing of reaction time (under postural conditions), there were no changes across any other neuromotor/mechanical measures. This result indicates that the ACLR group had a reduced ability to respond to unexpected stimuli. Overall, the results of this investigation suggest that ACL damage has a wide-spread impact as it not simply localized to the injured knee. The collective results from these studies show changes in movement strategy prioritization in those with an ACLR. These novel findings provide an alternate perspective and may change the ways in which clinicians and healthcare providers assess individuals who have had ACL reconstructive surgery

The Effects of the Traditional Scaling Technique Versus a Modified Scaling Technique on Muscle Activity and Pinch Force Generation: A Pilot Study

Purpose: Dental hygienists perform precision instrumentation tasks repetitively throughout the workday, placing them at increased risk for developing a musculoskeletal disorder. The purpose of this pilot study was to determine differences in muscle activity and pinch force generation between the traditional scaling technique and a modified scaling technique. Methods: A convenience sample of dental hygienists (n=12) acted as their own controls in this counterbalance-designed pilot study. Muscle activity and pinch forces were assessed while participants performed traditional and modified scaling techniques with designated instruments on artificial calculus applied to the lower left quadrant of a typodont, for a period of five minutes. Surface electromyography was used to measure muscle activity; sensors attached to the instrument handle measured pinch forces. Participants were surveyed regarding the instruments used and scaling technique preferences at the conclusion of the session. Parametric and non-parametric tests were used to analyze the data. Descriptive statistics were used to analyze the exit survey. Results: The modified scaling technique required less muscle activity than the traditional technique while scaling, however results were not significant (p \u3e0.05). The traditional scaling technique required greater overall pinch force during scaling (p =.00). Pairwise comparisons revealed significant differences between pinch force generation in the thumb for the two scaling techniques (Z = -2.401, p= 0.016) and in the index finger (Z = -2.223, p= 0.026). The traditional scaling technique generated more pinch force (thumb x = 7.25±4.99, index finger x=2.86±2.14) when compared to the modified scaling technique (thumb x=4.52±2.32, index finger x=1.65±1.28). Participants had a slightly higher preference for the instrument utilized for the modified scaling technique in terms of balance, maneuverability, overall comfort and the associated scaling technique as compared to the instrument utilized for the traditional scaling technique. Conclusion: Use of a modified scaling technique may reduce muscle activity and pinch force generation as compared to the traditional lateral pressure scaling technique during instrumentation. Future research on ergonomic scaling techniques is needed to determine their efficacy and impact on musculoskeletal disorders

Ocean Surfing as a Novel Physiotherapy Environment: A Commentary

Aquatic exercise for both fitness and rehabilitation are presently being offered to individuals of various special populations [1]. Pool programs offer physical activity and educational programming that can be particularly helpful for children with disabilities. The physiologic, psychologic, and social benefits of aquatic exercise are often found to be more pronounced in these children [2]

Chewing Speed Does Not Follow Typical Patterns of Motor Slowing with Age

Aging adults experience gradual structural changes in nerve and muscle tissues that impair their ability to exploit speed as an effective movement strategy. The aim of the study was to examine whether chewing rates demonstrate a level of age-related neuromotor decline similar to other motor tasks. Fifteen young (20-40 years) and fifteen healthy older adults (60+ years) completed a battery of motor tasks including: walking, finger tapping, simple reaction time, postural sway, and chewing. Gait metrics were collected using a 20-foot pressure-sensitive walkway. All walking was performed at a preferred speed. Participants tapped an accelerometer affixed to a table at a preferred rate. Upper extremity reaction time was recorded by depressing a mouse button with an associated timing mechanism, whereas a similar foot pedal interface was used to measure lower extremity reaction time. Postural sway data was collected using a force plate. Surface electromyography of the masseter was used to record fast(2Hz), slow(1Hz), and preferred chewing rates. Fast and slow chewing rates were set using an auditory metronome which was switched off during recording. Age comparisons for each task were performed using general linear modeling, with additional considerations for chewing speed effects and interactions for the chewing task. The results reveal that older adults demonstrate a general slowing of movement with the exception of chewing speed which appears to be preserved with aging. Regardless of age, preferred chewing rates were nearly identical. Preservation of chewing rates compared to other motor tasks may be due to the difference in anatomical innervation between muscles of mastication and the limbs. Masticatory muscles receive bilateral innervation including ipsilateral and contralateral inputs from the motor cortices, whereas limb muscles receive mainly unilateral innervation from the contralateral cortex. The neural redundancy may preserve chewing rates despite age-related degradation of the system.https://digitalcommons.odu.edu/health_sciences/1009/thumbnail.jp

The Additive Effects of Cell Phone Use and Dental Hygiene Practice on Finger Muscle Strength: A Pilot Study

Purpose: The purpose of this study was to determine strength of muscles involved with instrumentation (scaling) by dental hygienists and the additive effects of cellular (mobile) phone usage, as indicated by measurements of muscular force generation. Methods: A convenience sample of licensed dental hygienists currently in clinical practice (n=16) and an equal number of individuals not currently using devices/tools repetitively for work (n=16), agreed to participate in this pilot study. All participants completed a modified cell phone usage questionnaire to determine their use pattern and frequency. Upon completion of the questionnaire, participants\u27 force production in six muscle groups was measured using a hand-held dynamometer. Descriptive statistics were used to analyze the data. Results: A total of 16 licensed dental hygienists (n=16) and 16 participants with no history of using tools/devices repetitively for work (n=16), comprised the experimental and control groups, repectively. The control group generated greater muscle force than the experimental group for the abductor pollicis longus (p=0.045). Significant differences were identified when comparing the low mobile phone users in the experimental group to the control group for the flexor pollicis brevis (p=0.031), abductor pollicis longus (p=0.031), and flexor digitorum (p=0.006), with the control group demonstrating higher muscle force. Years in clinical practice and mobile phone use was shown to have a significant effect on muscular force generation for the flexor pollicis brevis (F=3.645, df=3, p=0.020) and flexor digitorum (F=3.560, df=3, p=0.022); subjects who practiced dental hygiene the longest produced the least amount of muscle force. Conclusion: Results from this pilot study indicate there are no significant additive effects of cell phone use and dental hygiene practice on finger muscles used for instrumentation. However, results indicate that dental hygiene practice demonstrated significant effects on muscular strength as compared to individuals who do not use tools/devices repetitively for work. The small sample size may have impacted results and the study should be repeated with a larger sample

The Effects of Dental Hygiene Instrument Handles on Muscle Activity Production

Purpose The objective of this study was to compare the effects of ten commercially available instrument handle designs’ mass and diameter on forearm muscle activity during a simulated periodontal scaling experience. Methods A convenience sample of 25 registered dental hygienists were recruited for this IRB-approved study. Ten commercially available instruments were categorized into four groups based on their masses and diameters: large diameter/light mass, small diameter/light mass, large diameter/heavy mass, and small diameter/heavy mass. Participants were randomized to four instruments with one from each group. Participants scaled with each instrument in a simulated oral environment while muscle activity was collected using surface electromyography. Muscle activity was compared among the four instrument group types. Results Muscle activity of the flexor digitorum superficialis was not significantly influenced by instrument mass (p=0.60) or diameter (p=0.15). Flexor pollicis longus muscle activity was not significantly influenced by instrument mass (p=0.81); diameter had a significant effect (p=0.001) with smaller diameter instruments producing more muscle activity. For the extensor digitorum communis and extensor carpi radialis brevis, instrument mass did not significantly affect muscle activity (p=0.64, p=0.43), while diameter narrowly failed to reach significance for both muscles (p=0.08, p=0.08); muscle activity for both muscles increased with smaller diameter instruments. Conclusion Results from this study indicate instrument diameter is more influential than mass on muscle activity generation; small diameter instruments increased muscle activity generation when compared to large diameter instruments. Future research in real-world settings is needed to determine the clinical impact of these findings

Development of a Wet Suit for Children with Down’s Syndrome

Individuals with Down syndrome have body types that make it difficult to fit for a standard wet suit. In general, their body composition includes an increase in central body adiposity and an endomorphic somatotypic body type in which the trunk is large while the limbs are shorter. Because of these physical characteristics, the participation by individuals with Down syndrome in aquatics exercise programs in which wet suits are needed can be very limiting. We observed that it was challenging to get these aquatic exercise participants into and out of the wet suits that had a standard wet suit design. This article describes a modified wet suit that is more accommodating for individuals with Down syndrome and allows them to wear the suit with less assistance. Although designed with the Down syndrome individual in mind, this modification may be useful for others with movement restrictions or who have an increase in central body fat

The Ocean as a Unique Therapeutic Environment: Developing a Surfing Program

Educational aquatic programming offers necessary physical activity opportunities to children with disabilities and the benefits of aquatic activities are more pronounced for children with disabilities than for their able-bodied peers. Similar benefits could potentially be derived from surfing in the ocean. This article describes an adapted surfing program that was designed to develop and enhance the children\u27s strength, flexibility, range of motion, coordination, balance, and psychosocial development. Throughout the program, the children and their surf instructors were encouraged to set realistic individual goals. Many positive outcomes were derived from the project, including gains in social development and self-confidence

Benefits of Surfing for Children with Disabilities: A Pilot Study

The purpose of this study was to assess the effectiveness of an eight-week surfing intervention for 16 children with disabilities. The assessment procedure consisted of pre and post physical fitness measures to determine the benefits of this intervention. Our results showed an overall improvement in upper body strength (right: P = 0.024, left: P = 0.022), core strength (P = 0.002) and cardiorespiratory endurance (P = 0.013). This research is the first of its kind, illustrating the feasibility and effectiveness of a surfing intervention on improving the physical fitness of children with disabilities