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Intramuscular EMG placement for two segments of gluteus minimus and three segments of gluteus medius with unique orientation and function
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Abstracts / Journal of Science and Medicine in Sport 14S (2011) e1–e119
formed pre and at 2, 5, 10 and 14 days following the exercise intervention. Measures included DOMS severity using a visual analogue scale (VAS) and pressure pain threshold (PPT) testing using an algometer. Physical performance capacity was measured by range of motion (ROM) assessment of the hip and knee, a vertical jump test and isokinetic peak torque test of the knee extensors. The control group performed 3 sets of 10 repetitions at 30% 1RM on a leg extension machine. The DOMS experimental group performed 8 sets of repetitions to failure at 80%1RM using a leg extension machine, followed by 3 sets of squats to failure using a Smith machine. Analysis was by repeated measures analysis of variance (ANOVA). Where significant interactions were found, paired t-tests were utilised to isolate individual intervention and time differences (p < 0.05). Results and conclusions: No significant muscle soreness or changes in performance over the testing period were reported by the control group. The DOMS group exercise protocol induced muscle soreness and tenderness which peaked at 48 hours with full soreness recovery within 5 days, thus DOMS was successfully induced. For the DOMS group, the exercise significantly decreased pressure pain threshold, ranges of motion and peak knee extension torque. Not all performance measures had fully returned to pre-intervention levels after 14 days. The time course of performance affects associated with a bout of DOMS differed from the time course of its overt symptoms. There were trends in measured variables for the DOMS group, when compared to the control group, that suggest a bout of DOMS could be used to elicit a supercompensation effect which may transfer to improved physical performance. Further research is needed to incontrovertibly prove that a bout of DOMS results in improved physical performance. doi:10.1016/j.jsams.2011.11.189 188 What child, family and environmental factors correlate with children’s movement skill proficiency? L. Barnett 1 , T. Hinkley 2 , K. Hesketh 3 , A. Okely 2 , J. Salmon 3,∗ 1 Health and Social Development, Deakin University, Australia 2 Wollongong University, Australia 3 Centre for Physical Activity and Nutrition Research, Deakin University, Australia
Purpose: Review evidence suggests fundamental motor skill is associated with physical activity. And yet there is little information on what factors influence movement skill. Methods: In 2009 Australian preschool-aged children were recruited as part of a cohort study (Healthy Active Preschool Years – HAPPY). Parent proxy-report of child (child sex, requests to be active, parent perception of child skill level, participation in structured and unstructured activ-
ity), parent (confidence of own skill to support child’s activity, parent-child physical activity interaction, parent physical activity) and environmental factors (play space visits, equipment at home) was collected. Physical activity (Actigraph GT1M accelerometer) and movement skill (Test of Gross Motor Development-2) were also assessed. After age adjustment, survey variables and physical activity (counts per minute and time in moderate-to-vigorous physical activity) were checked for association with raw object control (e.g. catching, throwing) and locomotor (e.g. jumping) scores. Variables with associations of p < .20 with either skill type were entered into two standard multiple regression models with locomotor and object control scores as respective outcome variables. Results: Movement skills were assessed for 76 (42 female, 34 male) children aged 3–6 years; 71 had complete parent proxy report and 53 had valid physical activity data. Child age, structured swimming participation, physical activity (cpm) and equipment explained 39% of locomotor skill variance; but equipment did not reach significance. Child age and sex, not participating in structured dance, moderate to vigorous physical activity (%), parent confidence of own skill and equipment explained 34% of object control variance; but child sex and parent confidence of own skill did not reach significance. Conclusion: Movement skill correlates differ somewhat according to skill type and are context specific. Whilst there is some evidence of correlates being multidimensional, child level correlates appear more important. doi:10.1016/j.jsams.2011.11.190 189 Intramuscular EMG placement for two segments of gluteus minimus and three segments of gluteus medius with unique orientation and function Semciw 1,2,∗ , T. Pizzari 1,2 , R. Green 2,3 1 Department of Physiotherapy, La Trobe University, Australia 2 Musculoskeletal Research Centre, La Trobe University, Australia 3 Department of Human Biosciences, La Trobe University, Australia
Introduction: Anatomical research suggests that gluteus minimus has two intramuscular segments (anterior and posterior) and gluteus medius has three (anterior, middle and posterior), each with unique functional roles based on independent fascicular orientation. Hip abductor muscle dysfunction may therefore potentially be explained by altered activation patterns of segments within these muscles. Previous intramuscular electromyography (EMG) research aimed at defining the roles of these segments fails to compare multiple segments within a muscle and only the posterior gluteus medius electrode location has been verified. The aim of this
Abstracts / Journal of Science and Medicine in Sport 14S (2011) e1–e119
case study was first to verify electrode placement guidelines for the proposed segments of gluteus minimus and gluteus medius according to unique fascicular arrangement, and second to assess these locations in vivo. Methodology: Anatomical research and cadaver observations aided the development of electrode placement locations with reference to major surface landmarks. To verify the locations developed, the gluteal region of one male cadaver was marked for fine wire electrode insertions. Five spinal needles were used to insert electrodes into the marked regions of gluteus minimus (anterior and posterior) and gluteus medius (anterior, middle and posterior). Following insertion, the gluteal region was carefully dissected and the location of the electrodes confirmed. The orientation of fascicles surrounding these electrodes was described. The same electrode placement procedure was repeated in vivo and electrodes were inserted with the additional aid of real-time ultrasound. Segmental EMG characteristics were then compared during a functional task. Results: The electrodes were successfully inserted into the described segments of gluteus minimus and gluteus medius in the cadaver, and the fascicle orientation surrounding these electrodes was consistent with segments described in past anatomical research. Unique segmental EMG characteristics in vivo were successfully illustrated during pilot testing and results will be presented at the conference. Conclusion: The electrode placement guidelines developed were verified according to fascicle orientation and unique EMG characteristics displayed in each segment. Further studies investigating the role of these muscle segments in health and dysfunction are currently underway in our laboratory. doi:10.1016/j.jsams.2011.11.191 190 Assessing various body composition measurements as an appropriate tool for estimating body fat in Division I female collegiate athletes P. Cross, A. Shim ∗ , A. Verhulst, A. Trost, R. Schmidt, R. Lynde, P. Hauer The University of South Dakota, USA Purpose: The purpose of the study was to determine if various cost affordable body composition measurements are adequate for measuring body composition in female college athletes when compared to the BOD POD. Methods: Thirty-two Division I track and field and basketball female athletes participated in the study. Within one hour, all subjects underwent body composition assessments via waist-to-hip ratio (WHR), body mass index (BMI), BOD POD, skinfold measurements, and bioelectrical impedance analysis (BIA). Results: No significant differences were found between basketball and track athletes and data was normalized. Per
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Pearson correlations, moderate correlations existed between body fat percentages obtained by BOD POD and BMI (r = .531) and between BOD POD and skinfold (r = .689). Low correlations existed between WHR and percentage body fat estimated by BOD POD (r = .403), as well as between body fat percentages estimated by BOD POD and BIA (r = .447). Conclusions: Results indicate that the skinfold technique had the highest correlation when compared to the BOD POD. Skinfold measurements may be used as a quick, affordable, and reliable technique when performed by an expert assessor. doi:10.1016/j.jsams.2011.11.192 191 A time-motion analysis of field training in elite soccer during the competitive season B. Scott, D. Taaffe ∗ University of Newcastle, United Kingdom Time-motion analysis of match performance in elite soccer has been studied extensively in recent years. To date, however, no published research has been conducted to analyse the movement characteristics of complete field training sessions in elite soccer. Purpose: The current study aimed to quantify the movement characteristics of field training for elite soccer during the competitive season. Methods: 15 professional soccer players (age 24.9; range 18-36 years; mass 77.6ÝñÝ7.5Ýkg) encompassing a range of field playing positions were monitored across 23 field training sessions (nÝ=Ý94) during the 2010-2011 Australian A-League season. Players completed training sessions whilst wearing a Minimaxx GPS device (Firmware v6.59; Catapult Innovations, Scoresby, Australia) recording at 5ÝHz. The GPS unit was positioned in a pocket located between the scapulae, in an undergarment worn by the player. SessionRPE was recorded using a Category Ratio-10 scale 30Ýmin post session to quantify training intensity and internal training load (TL). Results: Session duration ranged from 38.2 to 117.1Ýmin. Total distance (TD) travelled was 4474.3ÝñÝ1335.6Ým, with meterage measuring 61.9ÝñÝ8.9Ýmúmin-1. Players covered 3907.6ÝñÝ1129.0Ým in low-intensity running (LIR; <14.4ÝkmÝh(1 ). Time spent in LIR was 70.3ÝñÝ16.7Ýmin, equating to 97.4ÝñÝ1.0% of the total training duration. Distance covered and time spent in high-intensity running (HIR; >14.4ÝkmÝh(1 ) were 561.9ÝñÝ268.2 m and 1.9ÝñÝ0.9Ýmin, with very high-intensity running (VHIR; >25.2ÝkmÝh(1 ) contributing 143.0ÝñÝ107.1Ým and 0.4ÝñÝ0.3Ýmin. Session-RPE recordings ranged from 1 to 8 (meanÝ=Ý4.2ÝñÝ1.6), and session-RPE internal TL was 320.4ÝñÝ168.9. Conclusions: It is evident that in-season field training sessions for elite soccer involved extensive periods of LIR and
Abstracts / Journal of Science and Medicine in Sport 14S (2011) e1–e119
formed pre and at 2, 5, 10 and 14 days following the exercise intervention. Measures included DOMS severity using a visual analogue scale (VAS) and pressure pain threshold (PPT) testing using an algometer. Physical performance capacity was measured by range of motion (ROM) assessment of the hip and knee, a vertical jump test and isokinetic peak torque test of the knee extensors. The control group performed 3 sets of 10 repetitions at 30% 1RM on a leg extension machine. The DOMS experimental group performed 8 sets of repetitions to failure at 80%1RM using a leg extension machine, followed by 3 sets of squats to failure using a Smith machine. Analysis was by repeated measures analysis of variance (ANOVA). Where significant interactions were found, paired t-tests were utilised to isolate individual intervention and time differences (p < 0.05). Results and conclusions: No significant muscle soreness or changes in performance over the testing period were reported by the control group. The DOMS group exercise protocol induced muscle soreness and tenderness which peaked at 48 hours with full soreness recovery within 5 days, thus DOMS was successfully induced. For the DOMS group, the exercise significantly decreased pressure pain threshold, ranges of motion and peak knee extension torque. Not all performance measures had fully returned to pre-intervention levels after 14 days. The time course of performance affects associated with a bout of DOMS differed from the time course of its overt symptoms. There were trends in measured variables for the DOMS group, when compared to the control group, that suggest a bout of DOMS could be used to elicit a supercompensation effect which may transfer to improved physical performance. Further research is needed to incontrovertibly prove that a bout of DOMS results in improved physical performance. doi:10.1016/j.jsams.2011.11.189 188 What child, family and environmental factors correlate with children’s movement skill proficiency? L. Barnett 1 , T. Hinkley 2 , K. Hesketh 3 , A. Okely 2 , J. Salmon 3,∗ 1 Health and Social Development, Deakin University, Australia 2 Wollongong University, Australia 3 Centre for Physical Activity and Nutrition Research, Deakin University, Australia
Purpose: Review evidence suggests fundamental motor skill is associated with physical activity. And yet there is little information on what factors influence movement skill. Methods: In 2009 Australian preschool-aged children were recruited as part of a cohort study (Healthy Active Preschool Years – HAPPY). Parent proxy-report of child (child sex, requests to be active, parent perception of child skill level, participation in structured and unstructured activ-
ity), parent (confidence of own skill to support child’s activity, parent-child physical activity interaction, parent physical activity) and environmental factors (play space visits, equipment at home) was collected. Physical activity (Actigraph GT1M accelerometer) and movement skill (Test of Gross Motor Development-2) were also assessed. After age adjustment, survey variables and physical activity (counts per minute and time in moderate-to-vigorous physical activity) were checked for association with raw object control (e.g. catching, throwing) and locomotor (e.g. jumping) scores. Variables with associations of p < .20 with either skill type were entered into two standard multiple regression models with locomotor and object control scores as respective outcome variables. Results: Movement skills were assessed for 76 (42 female, 34 male) children aged 3–6 years; 71 had complete parent proxy report and 53 had valid physical activity data. Child age, structured swimming participation, physical activity (cpm) and equipment explained 39% of locomotor skill variance; but equipment did not reach significance. Child age and sex, not participating in structured dance, moderate to vigorous physical activity (%), parent confidence of own skill and equipment explained 34% of object control variance; but child sex and parent confidence of own skill did not reach significance. Conclusion: Movement skill correlates differ somewhat according to skill type and are context specific. Whilst there is some evidence of correlates being multidimensional, child level correlates appear more important. doi:10.1016/j.jsams.2011.11.190 189 Intramuscular EMG placement for two segments of gluteus minimus and three segments of gluteus medius with unique orientation and function Semciw 1,2,∗ , T. Pizzari 1,2 , R. Green 2,3 1 Department of Physiotherapy, La Trobe University, Australia 2 Musculoskeletal Research Centre, La Trobe University, Australia 3 Department of Human Biosciences, La Trobe University, Australia
Introduction: Anatomical research suggests that gluteus minimus has two intramuscular segments (anterior and posterior) and gluteus medius has three (anterior, middle and posterior), each with unique functional roles based on independent fascicular orientation. Hip abductor muscle dysfunction may therefore potentially be explained by altered activation patterns of segments within these muscles. Previous intramuscular electromyography (EMG) research aimed at defining the roles of these segments fails to compare multiple segments within a muscle and only the posterior gluteus medius electrode location has been verified. The aim of this
Abstracts / Journal of Science and Medicine in Sport 14S (2011) e1–e119
case study was first to verify electrode placement guidelines for the proposed segments of gluteus minimus and gluteus medius according to unique fascicular arrangement, and second to assess these locations in vivo. Methodology: Anatomical research and cadaver observations aided the development of electrode placement locations with reference to major surface landmarks. To verify the locations developed, the gluteal region of one male cadaver was marked for fine wire electrode insertions. Five spinal needles were used to insert electrodes into the marked regions of gluteus minimus (anterior and posterior) and gluteus medius (anterior, middle and posterior). Following insertion, the gluteal region was carefully dissected and the location of the electrodes confirmed. The orientation of fascicles surrounding these electrodes was described. The same electrode placement procedure was repeated in vivo and electrodes were inserted with the additional aid of real-time ultrasound. Segmental EMG characteristics were then compared during a functional task. Results: The electrodes were successfully inserted into the described segments of gluteus minimus and gluteus medius in the cadaver, and the fascicle orientation surrounding these electrodes was consistent with segments described in past anatomical research. Unique segmental EMG characteristics in vivo were successfully illustrated during pilot testing and results will be presented at the conference. Conclusion: The electrode placement guidelines developed were verified according to fascicle orientation and unique EMG characteristics displayed in each segment. Further studies investigating the role of these muscle segments in health and dysfunction are currently underway in our laboratory. doi:10.1016/j.jsams.2011.11.191 190 Assessing various body composition measurements as an appropriate tool for estimating body fat in Division I female collegiate athletes P. Cross, A. Shim ∗ , A. Verhulst, A. Trost, R. Schmidt, R. Lynde, P. Hauer The University of South Dakota, USA Purpose: The purpose of the study was to determine if various cost affordable body composition measurements are adequate for measuring body composition in female college athletes when compared to the BOD POD. Methods: Thirty-two Division I track and field and basketball female athletes participated in the study. Within one hour, all subjects underwent body composition assessments via waist-to-hip ratio (WHR), body mass index (BMI), BOD POD, skinfold measurements, and bioelectrical impedance analysis (BIA). Results: No significant differences were found between basketball and track athletes and data was normalized. Per
e93
Pearson correlations, moderate correlations existed between body fat percentages obtained by BOD POD and BMI (r = .531) and between BOD POD and skinfold (r = .689). Low correlations existed between WHR and percentage body fat estimated by BOD POD (r = .403), as well as between body fat percentages estimated by BOD POD and BIA (r = .447). Conclusions: Results indicate that the skinfold technique had the highest correlation when compared to the BOD POD. Skinfold measurements may be used as a quick, affordable, and reliable technique when performed by an expert assessor. doi:10.1016/j.jsams.2011.11.192 191 A time-motion analysis of field training in elite soccer during the competitive season B. Scott, D. Taaffe ∗ University of Newcastle, United Kingdom Time-motion analysis of match performance in elite soccer has been studied extensively in recent years. To date, however, no published research has been conducted to analyse the movement characteristics of complete field training sessions in elite soccer. Purpose: The current study aimed to quantify the movement characteristics of field training for elite soccer during the competitive season. Methods: 15 professional soccer players (age 24.9; range 18-36 years; mass 77.6ÝñÝ7.5Ýkg) encompassing a range of field playing positions were monitored across 23 field training sessions (nÝ=Ý94) during the 2010-2011 Australian A-League season. Players completed training sessions whilst wearing a Minimaxx GPS device (Firmware v6.59; Catapult Innovations, Scoresby, Australia) recording at 5ÝHz. The GPS unit was positioned in a pocket located between the scapulae, in an undergarment worn by the player. SessionRPE was recorded using a Category Ratio-10 scale 30Ýmin post session to quantify training intensity and internal training load (TL). Results: Session duration ranged from 38.2 to 117.1Ýmin. Total distance (TD) travelled was 4474.3ÝñÝ1335.6Ým, with meterage measuring 61.9ÝñÝ8.9Ýmúmin-1. Players covered 3907.6ÝñÝ1129.0Ým in low-intensity running (LIR; <14.4ÝkmÝh(1 ). Time spent in LIR was 70.3ÝñÝ16.7Ýmin, equating to 97.4ÝñÝ1.0% of the total training duration. Distance covered and time spent in high-intensity running (HIR; >14.4ÝkmÝh(1 ) were 561.9ÝñÝ268.2 m and 1.9ÝñÝ0.9Ýmin, with very high-intensity running (VHIR; >25.2ÝkmÝh(1 ) contributing 143.0ÝñÝ107.1Ým and 0.4ÝñÝ0.3Ýmin. Session-RPE recordings ranged from 1 to 8 (meanÝ=Ý4.2ÝñÝ1.6), and session-RPE internal TL was 320.4ÝñÝ168.9. Conclusions: It is evident that in-season field training sessions for elite soccer involved extensive periods of LIR and