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Songbirds, which rely heavily upon acoustic communication, employ a variety of strategies to reduce the degree to which their songs are masked by other sounds within the environment. One such strategy is to make active adjustments to song timing to avoid temporally overlapping other environmental sounds. While playback studies in many different songbird species have demonstrated that territorial males avoid overlapping conspecific songs in that context, there is comparatively little known about how such behavior varies across contexts. For example, there is relatively little information on avoidance of overlapping in naturalistic interactions (e.g., countersinging) among conspecific singers; likewise, few studies have assessed the degree to which males avoid overlapping heterospecific songs. Songbird researchers have also explored possible communicative functions of song overlapping, most notably the idea that overlapping conveys information related to aggression. The objectives of the present study were to compare song overlapping across contexts and to assess the relationship between song overlapping and physical responses to conspecific playback in the Hermit Thrush (Catharus guttatus). Degree of song overlapping in response to conspecific (n = 29) and heterospecific playback (n = 31), as well as during naturally occurring countersinging (n-21 pairs), was compared to chance levels. Avoidance of overlapping occurred in all 3 contexts, although to a lesser degree in response to heterospecific playback. Comparison of physical responses to song overlapping during conspecific playback revealed no association, aligning with recent studies in other species indicating that song overlapping is not an aggressive signal. Instead, the avoidance of song overlapping appears to be an important tool for decreasing the risk of acoustic interference posed by both conspecific and heterospecific songs. Received 27 February 2023. Accepted 28 December 2023. Key words: acoustic interference, aggression, countersinging, heterospecific, playback. Las aves canoras, que dependen fuertemente de la comunicacion acustica, emplean una variedad de estrategias para reducir el grado en que sus canciones son enmascaradas por otros sonidos ambientales. Una de las estrategias que usan es hacer ajustes activos al ritmo de su canto para evitar traslape temporal con otros sonidos ambientales. Mientras estudios con cantos pregrabados en muchas especies de aves canoras han demostrado que machos territoriales evitan traslapes de cantos conespecificos en ese contexto, se conoce compa-rativamente poco acerca de como ese comportamiento varia en diferentes contextos. Por ejemplo, existe relativamente poca informacion en como evitan el traslapes en interacciones en la naturaleza (por ejemplo contra-cantos) entre cantantes conespecificos; igualmente, pocos estudios han evaluado el grado en que machos evitan cantos heteroespecificos que se traslapan. Investigadores de aves canoras tambien han explorado posibles funciones comunicativas del traslape de cantos, notablemente la idea de que cantos que se traslapan brindan informacion relacionada a agresion. Los objetivos del presente estudio fueron comparar sobrelapamiento de cantos en diferentes contextos y evaluar la relacion entre el sobrelapamiento del canto y las respuestas fisicas a los cantos pregrabados de un conespecifico en zorzal Catharus guttatus. El grado de sobrelapamiento de canto en respuesta a los cantos pregrabados de un conespecifico (n=29), a los cantos pregrabados de un heteroespecifico (n=31) y contra-cantos que ocurrian naruralmente (n=21 pares), comparados con el azar. Evitar el traslape ocurrio en los tres contextos, aunque en menor grado en el caso de cantos pregrabados de heteroespecificos. La comparacion de respuestas fisicas al traslape de cantos durante los cantos pregrabados de conespecificos no mostraron asociacion, lo que concuerda con estudios recientes en otras especies que indican que el traslape de canto no es una serial agresiva. En vez de eso, evitar el traslape de canto parece ser una herramienta importante para disminuir el riesgo de interferencia acustica que presentan tanto cantos conespecificos como heteroespecificos. Palabras clave: interferencia acustica, agresion, contra-cantos, heteroespecifico, reproduccion de grabaciones., Songbirds rely on acoustic communication to convey important information related to identity, aggression, and mating (Catchpole and Slater 2008). While this mode of communication has advantages over other forms, including [...]

Background: Both autografts and allografts are used to reconstruct the anterior cruciate ligament (ACL) after injury; however, it is unclear whether graft source affects lower extremity functional test performance or failure rate in an active military population. Objective: To compare lower extremity functional test performance and graft failure rates between ACL grafts [allograft, hamstring, bone-patellar tendon-bone (BTB)]. Study Design: Cross-sectional. Level of Evidence: Level 2. Methods: Ninety-eight cadets entering a US Service Academy with a history of unilateral ACL reconstruction (ACLR) agreed to participate. Before basic training, participants completed 4 lower extremity functional tests. Active injury surveillance was conducted within the study cohort to identify all subsequent graft failures. Results: Cadets with hamstring autografts outperformed the BTB and allograft groups on the Lower Quarter Y-Balance Test-Posteromedial direction and single-leg hop test, respectively. No differences were detected by graft type for the other functional tests. The incidence of subsequent ipsilateral graft failures in patients with autograft was 8.11%. No failures were observed in the allograft group during the follow-up period. After controlling for sex, joint hypermobility, and time since injury and surgery, the risk of graft failure was 9.8 times higher for patients with a hamstring autograft than with a BTB (P = 0.045). Conclusion: After ACLR, graft type appears to influence some single-limb measures of lower extremity function and the risk of subsequent failure. Hamstring autografts demonstrated better functional performance but increased risk of graft failure. Clinical Relevance: Surgeons need to weigh the pros and cons of all graft options in relation to the patient's lifestyle. Regardless of graft type, individuals with an ACLR may require additional rehabilitation to regain neuromuscular control during dynamic single-limb tasks and mitigate graft failure. [ABSTRACT FROM AUTHOR]

To better understand the use of birdsong in territorial defence, vocal responses to conspecific song playback were assessed in Hermit Thrush Catharus guttatus males. Subjects avoided both overlapping and frequency matching the playback songs. In addition, during playback, males performed abridged versions of their songs that lacked introductory notes. Overlapping and matching avoidance, as well as the use of abridged songs, may reflect subjects' efforts to maximize signal efficiency and avoid acoustic interference, even while actively engaged in territorial defence. Future work will explore that possibility, especially with respect to the use and function of abridged songs. [ABSTRACT FROM AUTHOR]

Introduction: Baseline symptom, balance, and neurocognitive scores have become an integral piece of the concussion management process. Factors such as sleep, learning disorders, fitness level, and sex have been linked to differences in performance on baseline assessments; however, it is unclear how tobacco use may affect these scores. The objective of this study was to compare baseline concussion assessment scores between service academy cadets who use and do not use tobacco.Methods: Cadets completed a standard battery of concussion baseline assessments per standard of care and were classified into two groups: tobacco users (n = 1,232) and nonusers (n = 5,922). Dependent variables included scores on the Balance Error Scoring System, Standardized Assessment of Concussion, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Brief Symptom Inventory-18, and Brief Sensation Seeking Scale (BSSS). Separate Mann-Whitney U-tests were used to compare all baseline assessment scores between groups with an adjusted P-value < 0.004.Results: Cadets that used tobacco performed significantly worse on the impulse control (P < 0.001) section of the ImPACT, reported greater ImPACT symptom severity scores (P < 0.001), and were more likely to take risks as measured by the BSSS (P < 0.001). No differences were detected for Balance Error Scoring System, Standardized Assessment of Concussion, Brief Symptom Inventory-18, and Sport Concussion Assessment Tool-3 symptom scores, verbal memory, visual memory, visual-motor speed, or reaction time on the ImPACT (P > 0.004).Conclusions: Tobacco users performed significantly worse than tobacco nonusers on the impulse control section of the ImPACT, reported greater symptom severity scores on the ImPACT, and were more likely to take risks as measured by the BSSS. Despite statistical significance, these results should be interpreted with caution, as the overall effect sizes were very small. Future research should examine the influence of tobacco use on recovery post-concussion. [ABSTRACT FROM AUTHOR]

Objectives: The Balance Error Scoring System (BESS) is commonly used to measure postural stability; however, it has demonstrated inconsistent reliability values when administered by humans. The Tekscan MobileMat™ was developed to automate the assessment of BESS errors and eliminate rater subjectivity. The objective of this study was to report reference values for the BESS, as measured by the MobileMat™, and examine the effect of sex, concussion history, and competitive sport level on BESS performance. Methods: Four hundred and forty participants performed the BESS on the MobileMat™. Participants were asked to maintain each stance with their eyes closed for 20 s. The MobileMat™ was used to quantify the number of errors. Results: Concussion history (p = 0.279-0.979) and competitive sport level (p = 0.422-0.979) did not affect BESS performance. Males performed significantly better than females for the single-limb foam stance (p = 0.032). No sex differences were detected for the other BESS stances or BESS total score (p = 0.067-0.744). Conclusions: Previously reported reference values in collegiate athletes and adolescents were slightly higher thus highlighting the value in establishing population norms and in developing new technologies to objectively quantify BESS performance. Furthermore, sex, concussion history, and competitive sport level do not appear to influence BESS performance as measured by the MobileMat™. [ABSTRACT FROM AUTHOR]

Background: Proper alignment of the scapula during upper extremity motion is important in maintaining shoulder joint function and health. Push-up plus exercise is considered as one of the best exercise to strengthen the muscles that stabilize the scapula. The purpose of the study is to examine the effects of push-up plus variants and elbow position on vertical ground reaction force and electromyographical activity of four shoulder muscles during concentric contraction. Methods: A total of 22 healthy subjects volunteered for the study. Each of the subjects performed both modified and traditional push-up plus. Modified push-up plus was performed with both knees and hands touching the ground while the traditional push-up plus was executed with hands and feet contacting the ground. Electromyography (EMG) of the upper trapezius (UT), lower trapezius (LT), infraspinatus (INFRA), and serratus anterior (SA), and vertical ground reaction forces (vGRF) were collected. Results: The traditional push-up plus exhibited higher EMG activity in all muscles tested (P < .05) and vertical ground reaction force (P < .001) compared to modified push-up plus. The highest difference in EMG activity between the two exercises was observed with the Serratus Anterior muscle (22%). Additionally, the traditional push-up plus presented a higher vGRF compared to the modified push-up plus (P < .001) by 17%. The SA had the greatest EMG activity compared to the other muscles tested during the concentric phase of the traditional push-up plus, and this did not occur during the plus phase of the exercise. Conclusion: The highest activity of the serratus anterior occurred at 55° of elbow extension during the concentric phase of the traditional PUP and not at the plus phase of the exercise. This suggests that when prescribing an exercise to target the serratus anterior, a traditional push-up is adequate and the plus-phase is not necessary. However, for patients that cannot perform a traditional push-up, the modified push-up plus would be a great alternative to strengthen their serratus anterior. [ABSTRACT FROM AUTHOR]

Background: Patellofemoral pain is a common condition without a clear mechanism for its presentation. Recently significant focus has been placed on the hip and its potential role in patellofemoral pain (PFP). The majority of the research has examined hip strength and neuromuscular control. Less attention has been given to hip mobility and its potential role in subjects with PFP. Purpose/Aim: The purpose of this study was to compare passive hip range of motion (ROM) of hip extension and hip internal and external rotation in subjects with PFP and healthy control subjects. The hypothesis was that subjects with PFP would present with less total hip ROM and greater asymmetry than controls. Design: Two groups, case controlled. Setting: Clinical research laboratory Participants: 30 healthy subjects without pain, radicular symptoms or history of surgery in the low back or lower extremity joints and 30 subjects with a diagnosis of PFP. Main Outcome Measures: Passive hip extension, hip internal rotation (IR) and hip external rotation (ER). A digital inclinometer was used for measurements. Results: There was a statistically significant difference ( p<0.001) in hip passive extension between the control group and the PFP group bilaterally. Mean hip extension for the control group was 6.8° bilaterally. For the PFP group, the mean hip extension was -4.0° on the left and -4.3° on the right. This corresponds to a difference of means between groups of 10.8° on the left and 11.1° on the right with a standard error of 2.1° . There was no statistically significant difference (p>0.05) in either hip IR or ER ROM or total rotation between or within groups. Conclusions: The results of this study indicate that a significant difference in hip extension exists in subjects with PFP compared to controls. These findings suggest that passive hip extension is a variable that should be included within the clinical examination of people with PFP. It may be valuable to consider hip mobility restrictions and their potential impact on assessment of strength and planned intervention in subjects with PFP. Level of Evidence: 2b [ABSTRACT FROM AUTHOR]

BACKGROUND: Hip range of motion is an important component in assessing clinical orthopedic conditions of the hip, low back and lower extremities. However it remains unclear as to what constitutes the best tool for clinical measurement. The purpose of this study was to investigate the concurrent validity of passive range of motion (ROM) measurements of hip extension and hip internal and external rotation using a digital inclinometer and goniometer. DESIGN: Criterion Standard. SETTING: Clinical research laboratory. PARTICIPANTS: 30 healthy subjects without pain, radicular symptoms or history of surgery in the low back or hip regions. MAIN OUTCOME MEASURES: Passive hip range of motion for extension, hip internal rotation and hip external rotation. A digital inclinometer and universal goniometer were utilized as the tools for comparisons between measurements. RESULTS: There was a statistically significant difference (p < 0.05) between the goniometer and digital inclinometer in measured hip ROM except for measurements of right hip external rotation (p > 0.05). The mean difference between the goniometer and digital inclinometer in left hip extension, internal rotation and external rotation were 3.5°, 4.5° and 5.0° respectively. The mean difference between the two devices in right hip extension, internal rotation and external rotation were 2.8°, 4.2° and 2.6° respectively. On average, the difference between the goniometer and digital inclinometer in extension was 3.2°, internal rotation was 4.5° and external rotation was 3.8°. The digital inclinometer had greater measurement during EXT and ER. Furthermore, there was no statistically significant difference (p > 0.05) in hip ROM between the left and right side for either goniometric or digital inclinometer measurements. CONCLUSIONS: This results of this study indicate that a significant difference exists between the two devices in all measurements with exception of right hip extension. The differences were noted to be between 3-5 degrees for all planes measured. These findings suggest that caution should be used if these two devices are to be used interchangeably to quantify passive hip range of motion in either clinical practice or when comparing studies that utilize different instruments. LEVEL OF EVIDENCE: 2b. [ABSTRACT FROM AUTHOR]

Abstract: Endogenous opioid peptide systems diminish stress-induced autonomic nervous system, neuroendocrine (hypothalamic-pituitary-adrenal axis) and behavioral responses, attenuating a collection of physiological symptoms basic to emotional and affective states. Neurogenic stressors may incite specific central changes in opioid peptide availability as well as changes in mu and delta-opioid receptor function. The present investigation evaluated the proactive influence of an intracerebroventricular injection of the opioid receptor agonist d-Pen2, d-Pen5-enkephalin (DPDPE) (0 μg, 0.005 μg, 1.0 μg or 2.5 μg) on locomotor behavior of mice following uncontrollable footshock (Shock) or novel shock chamber exposure (No Shock). It was expected that DPDPE administration following Shock on Day 1 would restore locomotor activity up to 1 week and prevent shock-associated behavior of mice encountering a brief session of footshock 18 days later. Exposure to Shock reduced horizontal locomotor and vertical locomotor (rearing) activity of mice while 2.5 μg DPDPE restored behavior. Eighteen days following Shock and DPDPE challenge, mice were exposed to either an abbreviated session of footshock (Mild Stress) or the shock chamber (Cues). Mice in the No Shock and Shock groups administered 2.5 μg DPDPE on Day 1 did not exhibit any locomotor deficits in response to Mild Stress on Day 18. Mice in the Shock group administered 0.005 μg DPDPE on Day 1, did not exhibit exaggerated rearing deficits following ensuing Mild Stressor encounter relative to mice reexposed to Cues on Day 18. Taken together, these data show that (a) footshock differentially affects rearing and locomotor activity, (b) DPDPE administration increases locomotor activity for up to 1 week following footshock and DPDPE administration, (c) reexposure to Mild Stress affects rearing and locomotor performance differently depending on previous stressor history and DPDPE dose, (d) DPDPE affords long-lasting protection to previously non-stressed mice against the deleterious effects of subsequent mild stress on locomotor activity, while a low dose of DPDE is sufficient to prevent shock-induced sensitization of rearing deficits, 18 days following original stressor and drug presentation. Finally, our investigation demonstrates that DPDPE administration alters the behavioral impact of future stressful encounters and emphasizes the importance of investigating opioid mechanisms in chronic stress disorders. [Copyright &y& Elsevier]

Background: Non-specific low back pain is a common condition often without a clear mechanism for its presentation. Recently more attention has been placed on the hip and its potential contributions to non-specific chronic low back pain (NSCLBP). Emphasis in research has mainly been placed on motor control, strength and endurance factors in relation to NSCLBP. Limited focus has been placed on hip mobility and its potential contribution in subjects with NSCLBP., Purpose/aim: The aim of this study was to compare passive ROM in hip extension, hip internal rotation, hip external rotation and total hip rotation in active subjects with NSCLBP to healthy control subjects. The hypothesis was that active subjects with NSCLBP would present with decreased total hip ROM and greater asymmetry when compared to controls., Design: Two group case controlled., Setting: Clinical research laboratory., Participants: 30 healthy subjects without NSCLBP and 30 active subjects with NSCLBP. Subjects categorized as NSCLBP were experiencing pain in the low back area with or without radicular symptoms of greater than three months duration., Main Outcome Measure: Passive hip extension (EXT), hip internal rotation (IR), hip external rotation (ER) and total hip rotation ROM. A digital inclinometer was used for measurements., Results: There was a statistically significant difference (p<0.001) in hip passive extension ROM between the control group and the NSCLBP group bilaterally. Mean hip extension for the control group was 6.88 bilaterally. For the NSCLBP group, the mean hip extension was -4.28 bilaterally. This corresponds to a difference of means between groups of 10.88. There was no statistically significant differences (p>0.05) in hip IR, ER, or total rotation ROM between groups., Conclusions: The results of this study indicate that a significant difference in hip extension exists in active subjects with NSCLBP compared to controls. It may be important to consider hip mobility restrictions and their potential impact on assessment of strength in NSLBP subjects. Future studies may be needed to investigate the relationship between measurements and intervention strategies., Level of Evidence: 2b.