1
|
Abstract
Progressive training of horses focusses on the muscular development and flexibility to both the right and the left. However anecdotal evidence suggests that horses are not symmetrically structured through the thoracic region and this may have effects on saddle fitting and performance. The aim of this research was to determine if asymmetry exists in the thoracic musculoskeletal structure of ridden horses by analysing retrospective data of saddle fits (n=490) obtained from a saddle fitting company. A flexible wither tracer tool was used to obtain tracings of wither shape. Each tracing yielded four repeatable points (two on the left; two on the right) measured from the midline at the highest and lowest points of the withers. Descriptive assessments of shoulder, wither, and back shape, and demographic information on both horse and rider were recorded. A Wilcoxon signed-rank test compared the means of the wither shape measurements. A GLIMMIX procedure identified relationships between the wither measurements, descriptive assessments, and horse and rider demographics. The means of measurements from the wither tracer tool showed almost 60% of horses having larger measurements on the left side (P<0.0001). There was no effect of horse breed, age, sex, height or level of training on wither measurements (P>0.05). Rider age, gender, height, weight and level of training did not affect wither measurements (P>0.05). These results show that horses are asymmetric in their thoracic structure with a majority of horses larger on their left side than the right. This asymmetry may be due to genetics, environment or training and should be considered when fitting a saddle to the horse.
Collapse
Affiliation(s)
- K. Merkies
- Department of Animal Biosciences, University of Guelph, 50 Stone Rd E, Guelph, Ontario, N1G 2W1, Canada
- Campbell Centre for the Study of Animal Welfare, University of Guelph, 50 Stone Rd E, Guelph, Ontario, N1G 2W1, Canada
| | - J. Alebrand
- Department of Animal Biosciences, University of Guelph, 50 Stone Rd E, Guelph, Ontario, N1G 2W1, Canada
| | - B. Harwood
- Department of Animal Biosciences, University of Guelph, 50 Stone Rd E, Guelph, Ontario, N1G 2W1, Canada
| | - K. LaBarge
- Department of Animal Biosciences, University of Guelph, 50 Stone Rd E, Guelph, Ontario, N1G 2W1, Canada
| | - L. Scott
- Department of Animal Biosciences, University of Guelph, 50 Stone Rd E, Guelph, Ontario, N1G 2W1, Canada
| |
Collapse
|
2
|
Harwood B, Scherer J, Brown RE, Cornett KMD, Kenno KA, Jakobi JM. Neuromuscular responses of the plantar flexors to whole-body vibration. Scand J Med Sci Sports 2016; 27:1569-1575. [PMID: 28033657 DOI: 10.1111/sms.12803] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2016] [Indexed: 01/21/2023]
Abstract
Enhanced physical performance following whole-body vibration (WBV) has been attributed to increased muscle activity; however, few studies have measured the mechanisms underlying these changes. The objective of this study was to measure the responsiveness of the Ia pathway as well as contractile properties in 16 young adults (24±2 years, eight men, eight women) following repeated bouts of acute WBV (45 Hz, 2 mm). Hoffman reflexes (H-reflex), compound muscle action potentials (M-wave), and twitch contractile properties were measured prior to and immediately following five 1-minute WBV exposures, and at 3, 5, 10, and 20 minute post-WBV. M-wave and H-reflex amplitudes decreased by 8% (P<.001) and by 46% (P<.05), respectively, whereas peak twitch torque decreased by 9% (P<.01) and rate of twitch torque development slowed 8% (P<.05). Percent voluntary activation and maximal plantar flexor torque were unchanged as a consequence of WBV (P>.05). In response to acute WBV, the root mean square of the soleus electromyography signal (EMGRMS ) increased by 8%, while the EMGRMS of the lateral gastrocnemius increased by 3% (P<.05). These data indicate that the responsiveness of the Ia pathway is diminished and contractile function is impaired immediately following WBV, and that the neural mechanisms underlying improved performance following WBV lie in alternative hypotheses possibly involving spindle disfacilitation or Golgi afferent modulation.
Collapse
Affiliation(s)
- B Harwood
- Health and Exercise Science, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - J Scherer
- Human Kinetics, University of Windsor, Windsor, ON, Canada
| | - R E Brown
- Health and Exercise Science, York University, North York, ON, Canada
| | - K M D Cornett
- Health and Exercise Science, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - K A Kenno
- Human Kinetics, University of Windsor, Windsor, ON, Canada
| | - J M Jakobi
- Health and Exercise Science, University of British Columbia Okanagan, Kelowna, BC, Canada
| |
Collapse
|
3
|
Simpson CL, Arefin S, Smart RR, Harwood B, Jakobi JM. Duration of fascicle shortening is affected by muscle architecture and sex. Eur J Appl Physiol 2016; 116:2237-2245. [PMID: 27654877 DOI: 10.1007/s00421-016-3476-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 09/11/2016] [Indexed: 11/27/2022]
Abstract
PURPOSE The purpose of this study was to examine muscle fascicle properties of the gastrocnemius medialis (GM) during contraction and stretch between males and females. During contraction muscle fascicles shorten and pennation angles increase to generate force. Due to the elastic nature of the attached tendon, the fascicles continue to shorten when maximal force is achieved in order to sustain isometric force and this duration of fascicle shortening (DFS) can be observed with ultrasonography. Linear and curved muscle fascicles both display these kinetics; however, it is currently unknown if static stretch prior to a maximal voluntary contraction (MVC) alters the DFS and whether the effect differs between males and females. METHODS Subjects performed an isometric MVC of the plantar flexors before and after a 2-min maximal dorsi-flexion stretch. Plantar flexor force was measured and ultrasound videography used to record GM and Achilles tendon architecture. RESULTS Males were stronger than females (p = 0.004). The DFS was longer for females compared to males (p = 0.001) and the addition of a static stretch increased the DFS for curved (p = 0.002), but not linear, fascicles. Curved fascicles were longer (p = 0.05) with larger pennation angles (p = 0.04) for both males and females when compared to linear fascicles. Tendon excursion was greater (p = 0.05) post-stretch during contraction when compared to pre-stretch. CONCLUSIONS This study provides evidence that regardless of sex, curved muscle fascicles behave differently than linear fascicles and should be considered separately when muscle architecture is examined.
Collapse
Affiliation(s)
- C L Simpson
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - S Arefin
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - R R Smart
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - B Harwood
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - Jennifer M Jakobi
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, V1V 1V7, Canada.
| |
Collapse
|
4
|
Perry R, Murphy M, Rankin K, Cowett A, Haider S, Harwood B. “One problem became another”: a mixed-methods study of identification of and care for patients seeking abortion after sexual assault. Contraception 2014. [DOI: 10.1016/j.contraception.2014.05.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
5
|
Harwood B, Cornett KMD, Edwards DL, Brown RE, Jakobi JM. The effect of tendon vibration on motor unit activity, intermuscular coherence and force steadiness in the elbow flexors of males and females. Acta Physiol (Oxf) 2014; 211:597-608. [PMID: 24888350 DOI: 10.1111/apha.12319] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 12/31/2013] [Accepted: 05/23/2014] [Indexed: 12/01/2022]
Abstract
BACKGROUND Compartmentalized responses in motor unit (MU) activity of the short head (SH) and long head (LH) of the biceps brachii are observed following forearm position change. Differential muscle spindle afferent distribution has been proposed as a potential mechanism underlying this behaviour. Tendon vibration is an effective, non-invasive method of increasing muscle spindle afferent activity of a target muscle group offering a paradigm in which this hypothesis may be investigated further. AIM To determine the effect of tendon vibration on MU recruitment and discharge rates of the SH and LH, muscle activity of the elbow flexors and triceps brachii, intermuscular coherence among the SH, LH, brachioradialis and triceps brachii and force steadiness in young males and females during isometric elbow flexion. METHODS Intramuscular electromyography (EMG) of the SH and LH, and surface EMG of the elbow flexors were recorded pre- and post-vibration during low-force isometric contractions. Motor unit recruitment thresholds, MU discharge rates and MU discharge variability; surface EMG amplitude, intermuscular coherence and force steadiness were determined pre- and post-vibration. RESULTS Differential changes in all MU properties, EMG amplitude and intermuscular coherence were observed among elbow flexors. Although MU properties exhibited differential changes, they accounted for little variance in isometric force steadiness. However, intermuscular EMG coherence among all muscles investigated was reduced post-vibration. CONCLUSION Uncoupling of common oscillatory input as a result of differential muscle spindle afferent inputs to elbow flexors may be responsible for the reduction in force steadiness following tendon vibration and a forearm position change.
Collapse
Affiliation(s)
- B. Harwood
- Health and Exercise Science; University of British Columbia Okanagan; Kelowna BC Canada
- Department of Physiology; University of Arizona; Tucson AZ USA
| | - K. M. D. Cornett
- Health and Exercise Science; University of British Columbia Okanagan; Kelowna BC Canada
| | - D. L. Edwards
- Human Kinetics; University of Windsor; Windsor ON Canada
| | - R. E. Brown
- Health and Exercise Science; University of British Columbia Okanagan; Kelowna BC Canada
| | - J. M. Jakobi
- Department of Physiology; University of Arizona; Tucson AZ USA
| |
Collapse
|
6
|
Harwood B, Rice CL. Short interspike intervals and double discharges of anconeus motor unit action potentials for the production of dynamic elbow extensions. J Neurophysiol 2014; 111:2039-46. [PMID: 24554783 DOI: 10.1152/jn.00412.2013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Incidence of double discharges (DDs; >100 Hz) and short interspike intervals (ISIs; >50 to <100 Hz) is reported to vary widely among different muscles and tasks, with a higher incidence in motor unit (MU) trains of fast muscles and for the production of fast contractions in humans. However, it is unclear whether human muscles with a large composition of slower motor units exhibit DDs or short ISIs when activated with maximal synaptic drive, such as those required for maximal velocity dynamic contractions. Thus the purpose of this study was to determine the effect of increasing peak contraction velocity on the incidence of DDs and short ISIs in the anconeus muscle. Seventeen anconeus MUs in 10 young males were recorded across dynamic elbow extensions ranging from low submaximal velocities (16% of maximal velocity) up to maximal velocities. A low incidence of DDs (4%) and short ISIs (29%) was observed among the 583 MU trains recorded. Despite the low incidence in individual MU trains, a majority (71% and 94%, respectively) of MUs exhibited at least one DD or short ISI. The number of short ISIs shared no variance with MU recruitment threshold (R(2) = 0.02), but their distribution was skewed toward higher peak velocities (G = -1.26) and a main effect of peak elbow extension velocity was observed (P < 0.05). Although a greater number of short ISIs was observed with increasing velocity, the low incidence of DDs and short ISIs in the anconeus muscle is likely related to the function of the anconeus as a stabilizer rather than voluntary elbow extensor torque and velocity production.
Collapse
Affiliation(s)
- B Harwood
- Canadian Centre for Activity and Aging, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada; and
| | - C L Rice
- Canadian Centre for Activity and Aging, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada; and Department of Anatomy and Cell Biology, The University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
7
|
Harwood B, Dalton BH, Power GA, Rice CL. Motor unit properties from three synergistic muscles during ramp isometric elbow extensions. Exp Brain Res 2013; 231:501-10. [PMID: 24081681 DOI: 10.1007/s00221-013-3714-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 09/16/2013] [Indexed: 11/24/2022]
Abstract
Many tasks require synergistic activation of muscles that possess different architectural, mechanical, and neural control properties. However, investigations of the motor unit (MU) mechanisms which modulate force are mostly restricted to individual muscles and low forces. To explore the pattern of MU recruitment and discharge behavior among three elbow extensors (lateral and long heads of the triceps brachii, and anconeus) during ramp isometric contractions, recruitment thresholds of 77 MUs in five young men were determined and corresponding MU discharge rates were tracked in 1-s epochs over forces ranging from 0 to 75 % of maximal voluntary isometric force (MVC). Across all forces, MUs in the lateral head discharged at higher rates than those in the anconeus (p < 0.001, Δ = 0.23). When all MUs were considered, recruitment thresholds in the long head of the triceps brachii were higher than the lateral head (p < 0.05, Δ = 0.70) with a trend (p = 0.08, Δ = 0.48) for higher recruitment thresholds in the long head compared with the anconeus. Together, these data indicate a potential mechanical disadvantage of the long head of the triceps brachii at 0° shoulder flexion. However, among low-threshold MUs (<10 % MVC), recruitment thresholds were lower in the anconeus than in both heads of the triceps brachii consistent with the expected twitch contractile and fiber type differences among these muscles. These findings illustrate the importance of considering synergistic relations among muscles used for a coordinated task, and the sensitivity of synergies to muscle architectural, mechanical, and possibly specific synaptic input factors.
Collapse
Affiliation(s)
- B Harwood
- Department of Physiology, University of Arizona, Tucson, AZ, 85721, USA,
| | | | | | | |
Collapse
|
8
|
Harwood B, Choi I, Rice CL. Reduced motor unit discharge rates of maximal velocity dynamic contractions in response to a submaximal dynamic fatigue protocol. J Appl Physiol (1985) 2012; 113:1821-30. [PMID: 23085960 DOI: 10.1152/japplphysiol.00879.2012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Fatigability is highly task dependent wherein motor unit (MU) discharge rates and recruitment thresholds are affected differently depending on whether contractions are performed at maximal or submaximal intensities. Although much is described for isometric tasks, the behavior of MU properties during the production of maximal velocity dynamic contractions following submaximal fatiguing contractions is unknown. In seven young men, we evaluated changes in MU recruitment thresholds and MU discharge rates of the anconeus muscle during both submaximal and maximal dynamic elbow extensions following a submaximal dynamic fatiguing protocol of moderate intensity to velocity task failure. Velocity and power of the maximal dynamic contractions declined ∼45 and ∼55%, respectively, but these variables were unchanged for the submaximal target velocity contractions. Discharge rates of the 12 MUs at task failure were unchanged for submaximal dynamic contractions, but were decreased ∼20% for maximal dynamic and ballistic isometric contractions at task failure. MU recruitment thresholds of submaximal dynamic contractions decreased 52% at task failure, but were similar throughout the fatiguing protocol for maximal contractions. These findings support the concept of a common neural mechanism responsible for the relative declines in MU discharge rate associated with submaximal fatigability in both isometric and dynamic contractions.
Collapse
Affiliation(s)
- B Harwood
- School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
| | | | | |
Collapse
|
9
|
Harwood B, Rice CL. Changes in motor unit recruitment thresholds of the human anconeus muscle during torque development preceding shortening elbow extensions. J Neurophysiol 2012; 107:2876-84. [PMID: 22378176 DOI: 10.1152/jn.00902.2011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Rate of torque development and the subsequent movement velocity are modulated by motor unit (MU) properties, primarily MU discharge rate and MU recruitment threshold (MURT). In isometric conditions, MURTs have been shown to decrease with increased rates of torque development. It is unclear whether this relationship is similar in the production of dynamic shortening contractions. Using fast joint velocities to drive the system, we aimed to determine how anconeus MURTs recorded during the torque production phase preceding movement were affected in relation to the resultant peak elbow extension velocity. Recruitment thresholds of 17 MUs from 9 young men were tracked throughout non-isokinetic dynamic elbow extensions with velocities ranging from 64°/s to 500°/s at a constant resistance of 25% of maximal voluntary isometric contraction and during isometric elbow extensions (0°/s). Relative MURTs decreased ∼50% from the slowest (<25% of maximal velocity) to the fastest (>75% of maximal velocity) resultant velocity ranges (P < 0.05). Although a significant (P < 0.001) but weak (r = -0.27, R(2) = 0.08) relationship was observed between MURT and resultant peak elbow extension velocity for the group, only 7 of the 17 MUs displayed significant moderate (r = -0.40, R(2) = 0.17) to strong (r = -0.85, R(2) = 0.73) negative MURT-velocity relationships. These data indicate variable responses of MURTs with increasing resultant peak velocity, which may be related to the intrinsic properties of individual MUs.
Collapse
Affiliation(s)
- B Harwood
- Canadian Centre for Activity and Aging, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
| | | |
Collapse
|
10
|
Perry R, Harwood B, Cowett A, Yu M, Pappo E. Unintended pregnancy and other barriers to HPV vaccination completion. Contraception 2011. [DOI: 10.1016/j.contraception.2011.05.074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
11
|
Harwood B, Edwards DL, Jakobi JM. Age- and sex-related differences for electromyography gaps during daily activity and a discrete task. Gait Posture 2011; 34:6-12. [PMID: 21531563 DOI: 10.1016/j.gaitpost.2011.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 02/10/2011] [Accepted: 02/19/2011] [Indexed: 02/02/2023]
Abstract
Temporal patterns of quiescent electromyography termed 'gaps' were investigated in young and old men and women for a discrete task and daily activity. Gaps in women (1.3±3.2) and old adults (1.5±3.4) were fewer compared with men (4.7±6.7) and young adults (4.6±6.9) for the discrete task (p<0.001). Gap duration was shorter for women (0.1±0.2s) and old adults (0.1±0.3s) compared with men (0.2±0.3s) and young adults (0.2±0.2s) (p<0.01). For daily activity, gap number was similar with age, but gap duration and percentage of total time occupied by gaps were less in old compared with young adults (50%), and in women compared with men (43%) (p<0.001). Results suggest gap activity is sensitive to type and duration of activity and that old adults and women demonstrate less quiescent electromyography than young adults and men.
Collapse
Affiliation(s)
- B Harwood
- School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
| | | | | |
Collapse
|
12
|
Harwood B, Davidson AW, Rice CL. Motor unit discharge rates of the anconeus muscle during high-velocity elbow extensions. Exp Brain Res 2010; 208:103-13. [PMID: 21107544 DOI: 10.1007/s00221-010-2463-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Accepted: 10/10/2010] [Indexed: 10/18/2022]
Abstract
Motor unit recruitment and motor unit discharge rate (MUDR) have been widely studied in isometric conditions but minimally during velocity-dependent contractions. For isometric contractions, surface electromyography (EMG) activity of the elbow extensors plateaus at near maximal torques (Le Bozec et al. 1980; Le Bozec and Maton 1982). One study (Maton and Bouisset 1975) recorded single motor unit (MU) activity at maximal velocities; however, only the rate of the first interspike interval (ISI) was reported and likely was not representative of the average MUDR of the MU train. The purpose was to calculate average MUDRs of the anconeus during loaded velocity-dependent contractions from zero velocity (isometric) up to maximal velocity (V(max25)) through a large range of motion. A Biodex dynamometer was used to record elbow extension torque, position, and velocity. Single MU potentials were collected from the anconeus with intramuscular EMG, and surface EMG was sampled from the lateral head of the triceps brachii during maximal voluntary isometric contractions (MVCs) and velocity-dependent contractions loaded at 25% MVC over 120° range of motion at five target velocities (0, 25, 50, 75, 100%V(max25)). Elbow extension velocities ranged from 93 to 494°/s and average MUDR ranged from 11.8 Hz at 25%MVC to 39.0 Hz at 100%V(max25.) Overall average MUDRs increased as a function of velocity, although the root mean square of triceps brachii surface EMG plateaued at 50%V(max25). Piecewise regression analysis revealed two distinct linear ranges each described by a unique equation, suggesting that MUDRs of the anconeus enter a secondary range of firing, characterized by a steeper slope as velocity approaches maximum.
Collapse
Affiliation(s)
- B Harwood
- Canadian Centre for Activity and Aging, Faculty of Health Sciences, School of Kinesiology, The University of Western Ontario, London, ON N6A 3K7, Canada
| | | | | |
Collapse
|
13
|
Boe S, Dalton B, Harwood B, Doherty T, Rice C. Inter-rater reliability of motor unit number estimates and quantitative motor unit analysis in the tibialis anterior muscle. Clin Neurophysiol 2009; 120:947-52. [DOI: 10.1016/j.clinph.2009.02.168] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 01/28/2009] [Accepted: 02/24/2009] [Indexed: 12/13/2022]
|
14
|
Warden M, Cowett A, Harwood B. Patient selection and provision of the intrauterine device: a survey of primary care providers. Contraception 2008. [DOI: 10.1016/j.contraception.2008.04.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
15
|
Cabiya M, Cowett A, Harwood B. Intrauterine device knowledge, attitudes and experience among senior obstetrics and gynecology residents. Contraception 2008. [DOI: 10.1016/j.contraception.2008.04.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
16
|
Whitaker A, Terplan M, Gold M, Johnson L, Creinin M, Harwood B. Effect of a brief educational intervention on the attitudes of young women toward the intrauterine device. Contraception 2008. [DOI: 10.1016/j.contraception.2008.04.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
17
|
Harwood B, Edwards DL, Jakobi JM. Age- and sex-related differences in muscle activation for a discrete functional task. Eur J Appl Physiol 2008; 103:677-86. [DOI: 10.1007/s00421-008-0765-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2008] [Indexed: 10/22/2022]
|
18
|
Abstract
OBJECTIVE This study compares quality of life (QOL) and acceptability of medical versus surgical treatment of early pregnancy failure (EPF). DESIGN A randomised clinical trial of treatment for EPF compared misoprostol vaginally versus vacuum aspiration (VA). SETTING A multisite trial at four US Urban University Hospitals. POPULATION A total of 652 women with an EPF were randomised to treatment. METHODS Participants completed a daily symptom diary and a questionnaire 2 weeks after treatment. MAIN OUTCOME MEASURES The questionnaire assessment included subscales of the Short Form-36 Health Survey Revised for QOL and measures of wellbeing, recovery difficulties, and treatment acceptability. RESULTS The two groups did not differ in mean scores for QOL except bodily pain; medical treatment was associated with higher levels of bodily pain than VA (P < 0.001). Success of treatment was not related to QOL, but acceptability of the procedure was decreased for medical therapy if unsuccessful (P = 0.003). Type of treatment was not associated with differences in recovery, and the two groups reported similar acceptability except for cramping (P = 0.02), bleeding (P < 0.001), and symptom duration (P = 0.03). CONCLUSIONS Despite reporting greater pain and lower acceptability of treatment-related symptoms, QOL and treatment acceptability were similar for medical and surgical treatment of EPF. Acceptability, but not QOL, was influenced by success or failure of medical management.
Collapse
Affiliation(s)
- B Harwood
- Department of Obstetrics and Gynecology, University of Illinois at Chicago College of Medicine, Chicago, IL 60612, USA.
| | | | | |
Collapse
|
19
|
Harwood B, Leggat M, Krohn M. Factors associated with receiving postpartum sterilization at a private teaching hospital. Contraception 2006. [DOI: 10.1016/j.contraception.2006.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
20
|
Harwood B, Nguyen D. Knowledge and attitudes of pharmacists regarding emergency contraception in an urban health system. Contraception 2006. [DOI: 10.1016/j.contraception.2006.05.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
21
|
|
22
|
Lohr P, Reeves M, Hayes J, Harwood B, Creinin M. Oral mifepristone and buccal misoprostol administered simultaneously for abortion through 63 days gestation. Contraception 2006. [DOI: 10.1016/j.contraception.2006.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
23
|
Harwood B, Meyn L, Ballagh S, Raymond E, Archer D, Creinin M. Cervicovaginal colposcopic lesions associated with nonoxynol-9 spermicide use versus condom use in a low-risk population. Contraception 2006. [DOI: 10.1016/j.contraception.2006.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
24
|
Reeves M, Schreiber C, Harwood B, Creinin M. Acceptability of medical uterine evacuation among women with normal and abnormal first-trimester pregnancies. Contraception 2006. [DOI: 10.1016/j.contraception.2006.05.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
25
|
Tu J, Harwood B. DISINFESTATION OF RECIRCULATING NUTRIENT SOLUTION BY FILTRATION AS A MEANS TO CONTROL PYTHIUM ROOT ROT OF TOMATOES. ACTA ACUST UNITED AC 2005. [DOI: 10.17660/actahortic.2005.695.35] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
26
|
Creinin MD, Harwood B, Guido RS, Fox MC, Zhang J. Endometrial thickness after misoprostol use for early pregnancy failure. Int J Gynaecol Obstet 2005; 86:22-6. [PMID: 15207665 PMCID: PMC1360146 DOI: 10.1016/j.ijgo.2004.02.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2003] [Revised: 02/25/2004] [Accepted: 02/26/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVES To assess if there was any potential relationship between endometrial thickness and final treatment outcome in women successfully treated with misoprostol for a first trimester anembryonic gestation, embryonic demise or fetal demise. METHODS Eighty women were treated with up to two doses of misoprostol 800 microg vaginally for early pregnancy failure. Subjects were scheduled to return 2 (range 1-4), 7 (range 5-9) and 14 (range 12-17) days after treatment. Transvaginal ultrasonography was performed at each follow-up visit. RESULTS The median endometrial thickness at each of the follow-up visits for women who had expelled the gestational sac was 14 mm, 10 mm, and 7 mm, respectively. The endometrial thickness at the first follow-up visit exceeded 15 mm in 20 subjects (36%) and 30 mm in four subjects (7%). Only three women had a suction aspiration for bleeding after documented expulsion. The endometrial thickness for these women was 11, 13, and 14 mm at the first follow-up visit. CONCLUSIONS There is no obvious relationship between increasing endometrial thickness and the need for surgical intervention in women treated with misoprostol for early pregnancy failure.
Collapse
Affiliation(s)
- M D Creinin
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine and Magee Womens Research Institute, Pittsburgh, PA, USA.
| | | | | | | | | |
Collapse
|
27
|
Tu JC, Harwood B. An ultrastructural investigation of the 'microsclerotia' formed in single cells of root cortical cells associated with corky root rot of tomato. Commun Agric Appl Biol Sci 2003; 68:583-7. [PMID: 15151293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
White and Scott (1973) described two forms of microsclerotia associated with corky root rot of tomato, one being formed in single cells of the outer root cortical cells and the other produced in culture from isolation of diseased roots and in degenerated root debris. By assuming that both forms were of fungal origin, they conducted an ultrastructural study using the microsclerotia produced in culture but not those formed in single cells. They demonstrated that the microsclerotia from culture consisted of hardened, interwoven hyphae of the fungus, Pyrenochaeta lycopersici. Since there have been doubts about the nature of the microsclerotia formed in single cells, an ultrastructural study was conducted. The results demonstrated clearly that the 'microsclerotia' formed in single cells of the root cortical cells were not composed of fungal mycelia, indeed these blackened cells or 'microsclerotia' were filled with numerous crystallines. There was no evidence of the presence of fungal hyphae in or around these cells. Both diseased and healthy, and young and old root cortex cells of many cultivars of tomato contained cells filled with crystallines. Therefore, it is clear that the 'microsclerotia' formed in single cells of the outer cortex described by White and Scott are not microsclerotia of the fungus, P. lycopersici.
Collapse
Affiliation(s)
- J C Tu
- Agriculture and Agri-Food Canada, Greenhouse and Processing Crops Research Centre, Harrow, Ontario N0R 1G0, Canada
| | | |
Collapse
|
28
|
Abstract
Contraceptive vaginal rings (CVRs) contain sex steroids that diffuse through a plastic polymer ring at a constant rate and are absorbed directly through the vaginal epithelium into the systemic circulation. This delivery system provides many advantages over oral contraceptives (OCs), including avoidance of the first-pass effect through the liver, constant serum steroid levels, longer duration of use, and greater bioavailability of the hormones. CVRs containing progestin only are designed for continuous use for 3 to 6 months. Those containing progesterone alone are indicated for use in women who are breastfeeding. Large clinical trials of progestin-containing CVRs demonstrated good efficacy and safety of the CVR, with continuation rates similar to that of OCs. CVRs containing a combination of estrogen and progestin are designed to be used for 1 to 12 months in a cyclic manner similar to OCs, with withdrawal bleeding in the fourth week of each cycle. In clinical trials these CVRs have typical use efficacies similar to OCs, with an acceptable pattern of bleeding.
Collapse
Affiliation(s)
- B Harwood
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213-3180, USA
| | | |
Collapse
|
29
|
Affiliation(s)
- B Harwood
- Reproductive Women's and Children's Hospital, LAC+USC Medical Center, Los Angeles, CA, USA
| | | | | | | |
Collapse
|
30
|
Jain JK, Harwood B, Meckstroth KR, Mishell DR. Early pregnancy termination with vaginal misoprostol combined with loperamide and acetaminophen prophylaxis. Contraception 2001; 63:217-21. [PMID: 11376649 DOI: 10.1016/s0010-7824(01)00193-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The objectives of this prospective non-concurrent cohort study were to confirm the efficacy of vaginal misoprostol for early pregnancy termination and to determine whether the incidence of side effects is lower with prophylactic loperamide and acetaminophen. Two-hundred women with an intrauterine pregnancy < or =56 days gestational age seeking medical pregnancy termination in an ambulatory research clinic were enrolled in the study. One-hundred participants (group 1) ingested 4 mg of loperamide and 500 mg of acetaminophen before the vaginal placement of 800 mirog of misoprostol moistened with 2 mL of saline. If abortion had not occurred, the same regimen was repeated every 24 h (maximum three doses). One-hundred participants (group 2) from the same clinic who previously underwent the same misoprostol regimen without prophylactic medication served as a control group for comparison with respect to abortion success and the incidence of side effects. The rate of successful abortion was not statistically significantly different between the two groups (group 1 93%, group 2 89%). The incidence of opiate analgesic use was significantly less in group 1 (4%) compared with group 2 (16%) (OR 0.22, 95% CI 0.06-0.73, p = 0.01). There was a significantly lower incidence of diarrhea in group 1 (23%) compared with group 2 (44%) (OR 0.38, 95% CI 0.20-0.73, p = 0.003). There was no difference in the incidence of fever/chills or the incidence of emesis between the two groups. Vaginal misoprostol is effective for termination of pregnancy < or = 56 days and the incidence of diarrhea and the use of opiate analgesia is significantly reduced with prophylactic loperamide and acetaminophen.
Collapse
Affiliation(s)
- J K Jain
- Women's and Children's Hospital, LAC+USC Medical Center, Department of Obstetrics and Gynecology, Los Angeles, CA 90033, USA.
| | | | | | | |
Collapse
|
31
|
Harwood B, Mishell DR. Use of vaginal misoprostol for abortion. Hum Reprod 2000; 15:2686-8. [PMID: 11098046 DOI: 10.1093/humrep/15.12.2686-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
32
|
Burgess KA, Harwood B, Robinson M, Carney PA. Mammographer participation in a database research study. Radiol Technol 1999; 70:453-60. [PMID: 10427589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Affiliation(s)
- K A Burgess
- Department of Community and Family Medicine, Dartmouth Medical School, Hanover, NH, USA
| | | | | | | |
Collapse
|
33
|
Harwood B. Common products that cause uncommonly severe burn injuries. NFPA J 1996; 90:79-83. [PMID: 10154208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|
34
|
|
35
|
|
36
|
Tanz RD, Kloka A, Harwood B, Rightmier D. Negative chronotropic and antiarrhythmic properties of atropine and other tropane analogues on isolated cat heart preparations. Circ Res 1978; 42:467-73. [PMID: 630662 DOI: 10.1161/01.res.42.4.467] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
37
|
|
38
|
Rightmier D, Harwood B. Letter: Atropine-induced bradycardia. N Engl J Med 1973; 289:1039. [PMID: 4742206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|