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Does clinically measured ankle plantar flexor muscle strength or weakness correlate with gait velocity, ankle kinematics and kinetics during walking for healthy individuals?
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
Session PS05 Foot and Ankle
Session PS05 Foot and Ankle
Preferred foot strategy for sprint initiation in children
Does clinically measured ankle plantar flexor muscle strength or weakness correlate with gait velocity, ankle kinematics and kinetics during walking for healthy individuals?
N. Tottori 1,∗ , T. Kurihara 2 , M. Otsuka 2 , G. Cesar 3 , T. Isaka 2 1
Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan 2 College of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan 3 Department of Athletics, University of Nebraska – Lincoln, Lincoln, Nebraska, United States Research question: Sprinters set their preferred feet on starting blocks. Are there any strategies for children, who have not acquired mature sprint skill in accelerated run, to choose their preferred foot at sprint initiation? Introduction: Laterality and/or limb preference is determined by preferential use of unilateral limb in voluntary movements [1]. Although no significant difference was found in kinematics between preferred and non-preferred foot during gait initiation in adults [2], children seem to choose their motoric behavior dependent on their limb preference. If so, attaining high horizontal velocity of whole-body center of mass from 0 m/s (i.e., sprint initiation) could be affected by limb preference. The purpose of this study was to detect the preferred foot strategy on sprint initiation in children. Materials and methods: Thirty-three children participated (20 boys and 13 girls, age 12.8 ± 1.0 yrs). Lower limb preference was assessed in previous studies [3] (right = 21, left = 7). Four trials of 5-m sprint were performed. Sprint time was measured with a phototube sensor. Forces and resultant impulses from each foot were calculated with force platforms. At start position, participants were instructed to put one foot on the front platform and the other foot on the rear platform. No other instructions were given during the 1st and 2nd trials. The tester observed their preferential foot placing on the platform and the initial swinging leg. Then, for the 3rd and 4th trials, participants were instructed to replace their front and rear feet on starting position contrary to the 1st and 2nd trials, and the initial swing leg was observed. Front-rear (FR) strategy was defined as participants always using their front or rear legs as the initial swing leg, while right-left (RL) strategy was defined as participants using their preferred limb as the initial swing leg. Results: In the 1st and 2nd trials, 13 out of 33 participants put their right foot on the front and 20 participants set left on the front. Swing initiation from front leg was seen in 20 participants, while the rear leg initiation in 9. There was no significant correlation between limb preference, preferential foot placing, and initiating the swing. For the 3rd and 4th trials, 20 participants changed their initial swinging leg to the opposite side, suggesting FR strategy; while, 2 participants started with the same foot, suggesting RL strategy. The others had no constant strategy of initial swing leg. Sprint times of 3rd and 4th trials were significantly slower than the 1st and 2nd trials (p < 0.01). No significant differences in the maximum ground reaction force and impulse were found between trials (0.173 = p = 0.991). Discussion: The sprint initiation in children is determined by the front-rear strategy rather than the preferred foot strategy. References
S25
N.E. Akalan 1,∗ , A. Apti 2 , S. Kuchimov 3 , Y. Temelli 4 , A.R. Ozdinc¸ler 1 , M.M. Oren 5 1
Istanbul University, Faculty of Health Science, Istanbul, Turkey 2 Istanbul University Institute of Health Science, Istanbul, Turkey 3 Bogazici Univeristy, Institute of Biomedical Engineering, Istanbul, Turkey 4 Istanbul University, Faculty of Medicine, Istanbul, Turkey 5 Istanbul University, Istanbul Faculty of Medicine, Department of Public Health, Istanbul, Turkey Research question: Does clinical muscle strength and weakness assessments have relation with ankle kinetics and gait velocity for healthy participants? Introduction: Plantar flexor (PF) muscle weakness is common and considered as the primary factor for functional limitation [1]. It is crucial to accurately assess the muscle strength to improve function. Aim of the study is to investigate the relation between clinically measured PF muscle strength and ankle peak PF power generation (APFPG), peak ankle moment (PAM), peak PF velocity (PFV) and mean gait velocity (MGV) for healthy participants. Materials and methods: 18 able bodies (age: 23.88 ± 3.55 y.o.) participated in to study. To create temporary weakness, nondominant sides of PF muscles were stretched (135 s, 13 rep.) under the pain threshold (Fig. 1a and b) [2]. Before and after the stretching, PF muscle strengths were measured by HHD in knee extension (Fig. 1c) [3] and gait parameters were obtained by 3D gait analysis at self-selected speed. Partial correlation coefficients were used to calculate the strengths of the relationships between stretches and differences (?, the subtractions of the interested values) for both normalised (N/kg) and non-normalized HHD scores (N) and paired t-test was used for comparison. Results: For differences (? PF) after the stretching; normalised (23%) and non-normalized (34.08%) PF muscle strength significantly reduced (p < 0.001). In normalised HHD condition; there was no correlation between HHD scores and MGV for pre and ? conditions (r: −0.04; p: 0.9; r: −0.07, p: 0.83 resp.). HHD and PF moment have moderately correlated in pre-stretch (r: 0.45, p: 0.14) and strongly correlated in ? conditions (r: 0.63, p: 0.04). APFPG and HHD scores have moderately correlated with both pre and ? conditions.
[1] Sadeghi H, et al. Gait Posture 2000;12:34–45. [2] Dessery Y, et al. Gait Posture 2011;33:550–5. [3] Chapman JP, et al. Neuropsychologia 1987;25:579–84.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.050
Fig. 1. Stretching and measuring procedures.
S26
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
For non-normalized HHD scores, correlation strengths reduce for all the kinetic parameters. Discussion: Isometric nature of the HHD scores for PF muscles does not reflect their performance in gait for healthy individuals. The clinically measured muscle weakness and/or strength have very weak correlation with gait velocity. Only peak APFM is strongly correlated with normalised HHD. Because of the greater levels of APFPG are required for higher-level mobilities, and the calf muscles are the primers for APFPG, clinically measured both muscle strength and weakness have only moderate strength to establish the treatment protocol and to predict the walking performance in healthy individuals. In clinic, HHD scores should also be normalized with weight. References
(median 18%, IRQ 21) (between-group difference 18%, p = .028). The PtIC and magnitude of roll-back were highly correlated (rho = 0.9, p < 0.01). Discussion: Preliminary results suggest that a PtIC of less than 15% foot length is consistent with a present first rocker. The rollback measure is a useful adjunct to this measure, as any roll-back is indicative of a disrupted first rocker. However it cannot be used in isolation, as one child with a rigid plantarflexed foot exhibited an abnormal PtIC without roll-back. The magnitude and duration of roll-back may provide more sensitive information about the foot contact pattern, and this is currently being investigated. Data collection is continuing, with the aim of enabling a broader use of pedobarography in assessing the outcome of non-operative interventions targeting foot placement.
[1] Williams G, et al. J Head Trauma Rehabil 2013:28. [2] Fowles, et al. J Appl Physiol 2000:89. [3] LF VV, et al. J Phys Rehabil Med 2013:49.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.052
http://dx.doi.org/10.1016/j.gaitpost.2015.06.051
Session PS05 Foot and Ankle Session PS05 Foot and Ankle Prediction of first rocker using pedobarography A. Mudge 1,∗ , E. Wojciechowski 1 , J. Burns 2 1 Paediatric Gait Analysis Service of New South Wales, Sydney, Australia 2 Paediatric Gait Analysis Service of New South Wales, The University of Sydney (Faculty of Health Sciences), Sydney, Australia
Research question: Can pedobarography be used to measure heel-to-toe foot loading pattern? Introduction: Pedobarography is often used to measure treatment outcomes in children with cerebral palsy (CP) who have foot deformities. However, while changes in pressure distribution are able to be quantified using pedobarography, describing changes in the heel-to-toe foot loading pattern is more challenging. This is because the abnormal loading pattern seen in many children with CP is reflected by a centre-of-pressure (COP) trajectory that moves posteriorly after the point of initial contact (“roll-back”) before moving anteriorly. We have previously quantified the point of initial contact (PtIC) and the magnitude of roll-back to measure improvements in the gait of a child with CP when using functional electrical stimulation (9th Australasian Biomechanics Conference, University of Wollongong, November 30, 2014). The aim of this study was to validate these measures as an evaluation of heel-to-toe foot loading pattern. Materials and methods: Data from 7 children with hemiplegic CP who had undergone 3D gait analysis and pedobarography were reviewed. Pedobarography data were analysed for three walks for each side and results averaged. The PtIC for each walk was extracted and the magnitude of roll-back was calculated by subtracting the PtIC from the most posterior position of the COP trajectory. Both measures were expressed as a percentage of foot length. Measures from limbs with a present first rocker according to kinetic data were compared with limbs with an absent first rocker. A dorsiflexion moment (>0.05 Nm/kg) in the first five per cent of the gait cycle was used to indicate the presence of the first rocker. Results: The PtIC occurred significantly earlier in limbs with a present first rocker (median 9%, IRQ 4) than in those where the first rocker was absent (median 55%, IRQ 24) (between-group difference 45%, p = .018). Roll-back was absent or negligible when the first rocker was present (median 0%, IRQ 0.15) but was significantly greater in those trials where the first rocker was absent
The impact of obesity on plantar pressure and balance ability in children D. Patikas 1,∗ , E. Bilili 1 , E. Simantira 1 , A. Xenofondos 2,4 , D. Metaxiotis 3,4 1
Aristotle University of Thessaloniki, Serres, Greece Aristotle University of Thessaloniki, ELEPAP, Thessaloniki, Greece 3 Papageorgiou General Hospital, ELEPAP, Thessaloniki, Greece 4 Gait Analysis Laboratory, ELEPAP, Thessaloniki, Greece 2
Research question: To examine the differences in plantar pressure and balance ability between children with normal and increased body fat. We tested the effect of visual feedback and base of support during standing balance tasks using instrumented pedobarography. Introduction: Overweight and obese children often experience problems in gait and posture. Pedobarography has been implemented to examine the effect of excessive body weight on foot morphology and biomechanics [1]. However, it is not yet clear to what extent mechanisms that contribute to the ability to balance (proprioception, vision, vestibular system) are influenced by differences in body composition in children. This study was designed to examine the effect of excessive weight on the biomechanical and morphological parameters of children’s feet during static balance tasks. Materials and methods: Thirty-six children (13 girls) were divided depending on their body fat percentage, as estimated by the Jackson & Pollock [2] equation adjusted for age and sex. The overweight-obese (OG) and the control group (CG) were 11.0 ± 2.6 and 10.1 ± 2.7 years old, had 21.2 ± 8.0% and 11.6 ± 6.3% body fat, and 25.5 ± 4.0 and 17.6 ± 1.6 kg/m2 BMI, respectively. Static balance was assessed on one or two feet, with eyes open or closed, while standing on a foot scanner (EPS, COMEX, Athens, Greece) as still as possible. The star excursion balance and functional reach test were assessed as field tests. Level of significance a was set at 0.05. Results: OG had significantly lower medial arch index and larger contact surface than the CG indicating a pes planus. The difference was more prominent when standing on both feet. Variability of the center of pressure on the anterior–posterior and mediolateral axis did not demonstrate any significant differences between the two groups in any of the examined conditions (open/closed eyes vs. standing on left/right/both feet). The star excursion balance tests
Session PS05 Foot and Ankle
Session PS05 Foot and Ankle
Preferred foot strategy for sprint initiation in children
Does clinically measured ankle plantar flexor muscle strength or weakness correlate with gait velocity, ankle kinematics and kinetics during walking for healthy individuals?
N. Tottori 1,∗ , T. Kurihara 2 , M. Otsuka 2 , G. Cesar 3 , T. Isaka 2 1
Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan 2 College of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan 3 Department of Athletics, University of Nebraska – Lincoln, Lincoln, Nebraska, United States Research question: Sprinters set their preferred feet on starting blocks. Are there any strategies for children, who have not acquired mature sprint skill in accelerated run, to choose their preferred foot at sprint initiation? Introduction: Laterality and/or limb preference is determined by preferential use of unilateral limb in voluntary movements [1]. Although no significant difference was found in kinematics between preferred and non-preferred foot during gait initiation in adults [2], children seem to choose their motoric behavior dependent on their limb preference. If so, attaining high horizontal velocity of whole-body center of mass from 0 m/s (i.e., sprint initiation) could be affected by limb preference. The purpose of this study was to detect the preferred foot strategy on sprint initiation in children. Materials and methods: Thirty-three children participated (20 boys and 13 girls, age 12.8 ± 1.0 yrs). Lower limb preference was assessed in previous studies [3] (right = 21, left = 7). Four trials of 5-m sprint were performed. Sprint time was measured with a phototube sensor. Forces and resultant impulses from each foot were calculated with force platforms. At start position, participants were instructed to put one foot on the front platform and the other foot on the rear platform. No other instructions were given during the 1st and 2nd trials. The tester observed their preferential foot placing on the platform and the initial swinging leg. Then, for the 3rd and 4th trials, participants were instructed to replace their front and rear feet on starting position contrary to the 1st and 2nd trials, and the initial swing leg was observed. Front-rear (FR) strategy was defined as participants always using their front or rear legs as the initial swing leg, while right-left (RL) strategy was defined as participants using their preferred limb as the initial swing leg. Results: In the 1st and 2nd trials, 13 out of 33 participants put their right foot on the front and 20 participants set left on the front. Swing initiation from front leg was seen in 20 participants, while the rear leg initiation in 9. There was no significant correlation between limb preference, preferential foot placing, and initiating the swing. For the 3rd and 4th trials, 20 participants changed their initial swinging leg to the opposite side, suggesting FR strategy; while, 2 participants started with the same foot, suggesting RL strategy. The others had no constant strategy of initial swing leg. Sprint times of 3rd and 4th trials were significantly slower than the 1st and 2nd trials (p < 0.01). No significant differences in the maximum ground reaction force and impulse were found between trials (0.173 = p = 0.991). Discussion: The sprint initiation in children is determined by the front-rear strategy rather than the preferred foot strategy. References
S25
N.E. Akalan 1,∗ , A. Apti 2 , S. Kuchimov 3 , Y. Temelli 4 , A.R. Ozdinc¸ler 1 , M.M. Oren 5 1
Istanbul University, Faculty of Health Science, Istanbul, Turkey 2 Istanbul University Institute of Health Science, Istanbul, Turkey 3 Bogazici Univeristy, Institute of Biomedical Engineering, Istanbul, Turkey 4 Istanbul University, Faculty of Medicine, Istanbul, Turkey 5 Istanbul University, Istanbul Faculty of Medicine, Department of Public Health, Istanbul, Turkey Research question: Does clinical muscle strength and weakness assessments have relation with ankle kinetics and gait velocity for healthy participants? Introduction: Plantar flexor (PF) muscle weakness is common and considered as the primary factor for functional limitation [1]. It is crucial to accurately assess the muscle strength to improve function. Aim of the study is to investigate the relation between clinically measured PF muscle strength and ankle peak PF power generation (APFPG), peak ankle moment (PAM), peak PF velocity (PFV) and mean gait velocity (MGV) for healthy participants. Materials and methods: 18 able bodies (age: 23.88 ± 3.55 y.o.) participated in to study. To create temporary weakness, nondominant sides of PF muscles were stretched (135 s, 13 rep.) under the pain threshold (Fig. 1a and b) [2]. Before and after the stretching, PF muscle strengths were measured by HHD in knee extension (Fig. 1c) [3] and gait parameters were obtained by 3D gait analysis at self-selected speed. Partial correlation coefficients were used to calculate the strengths of the relationships between stretches and differences (?, the subtractions of the interested values) for both normalised (N/kg) and non-normalized HHD scores (N) and paired t-test was used for comparison. Results: For differences (? PF) after the stretching; normalised (23%) and non-normalized (34.08%) PF muscle strength significantly reduced (p < 0.001). In normalised HHD condition; there was no correlation between HHD scores and MGV for pre and ? conditions (r: −0.04; p: 0.9; r: −0.07, p: 0.83 resp.). HHD and PF moment have moderately correlated in pre-stretch (r: 0.45, p: 0.14) and strongly correlated in ? conditions (r: 0.63, p: 0.04). APFPG and HHD scores have moderately correlated with both pre and ? conditions.
[1] Sadeghi H, et al. Gait Posture 2000;12:34–45. [2] Dessery Y, et al. Gait Posture 2011;33:550–5. [3] Chapman JP, et al. Neuropsychologia 1987;25:579–84.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.050
Fig. 1. Stretching and measuring procedures.
S26
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
For non-normalized HHD scores, correlation strengths reduce for all the kinetic parameters. Discussion: Isometric nature of the HHD scores for PF muscles does not reflect their performance in gait for healthy individuals. The clinically measured muscle weakness and/or strength have very weak correlation with gait velocity. Only peak APFM is strongly correlated with normalised HHD. Because of the greater levels of APFPG are required for higher-level mobilities, and the calf muscles are the primers for APFPG, clinically measured both muscle strength and weakness have only moderate strength to establish the treatment protocol and to predict the walking performance in healthy individuals. In clinic, HHD scores should also be normalized with weight. References
(median 18%, IRQ 21) (between-group difference 18%, p = .028). The PtIC and magnitude of roll-back were highly correlated (rho = 0.9, p < 0.01). Discussion: Preliminary results suggest that a PtIC of less than 15% foot length is consistent with a present first rocker. The rollback measure is a useful adjunct to this measure, as any roll-back is indicative of a disrupted first rocker. However it cannot be used in isolation, as one child with a rigid plantarflexed foot exhibited an abnormal PtIC without roll-back. The magnitude and duration of roll-back may provide more sensitive information about the foot contact pattern, and this is currently being investigated. Data collection is continuing, with the aim of enabling a broader use of pedobarography in assessing the outcome of non-operative interventions targeting foot placement.
[1] Williams G, et al. J Head Trauma Rehabil 2013:28. [2] Fowles, et al. J Appl Physiol 2000:89. [3] LF VV, et al. J Phys Rehabil Med 2013:49.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.052
http://dx.doi.org/10.1016/j.gaitpost.2015.06.051
Session PS05 Foot and Ankle Session PS05 Foot and Ankle Prediction of first rocker using pedobarography A. Mudge 1,∗ , E. Wojciechowski 1 , J. Burns 2 1 Paediatric Gait Analysis Service of New South Wales, Sydney, Australia 2 Paediatric Gait Analysis Service of New South Wales, The University of Sydney (Faculty of Health Sciences), Sydney, Australia
Research question: Can pedobarography be used to measure heel-to-toe foot loading pattern? Introduction: Pedobarography is often used to measure treatment outcomes in children with cerebral palsy (CP) who have foot deformities. However, while changes in pressure distribution are able to be quantified using pedobarography, describing changes in the heel-to-toe foot loading pattern is more challenging. This is because the abnormal loading pattern seen in many children with CP is reflected by a centre-of-pressure (COP) trajectory that moves posteriorly after the point of initial contact (“roll-back”) before moving anteriorly. We have previously quantified the point of initial contact (PtIC) and the magnitude of roll-back to measure improvements in the gait of a child with CP when using functional electrical stimulation (9th Australasian Biomechanics Conference, University of Wollongong, November 30, 2014). The aim of this study was to validate these measures as an evaluation of heel-to-toe foot loading pattern. Materials and methods: Data from 7 children with hemiplegic CP who had undergone 3D gait analysis and pedobarography were reviewed. Pedobarography data were analysed for three walks for each side and results averaged. The PtIC for each walk was extracted and the magnitude of roll-back was calculated by subtracting the PtIC from the most posterior position of the COP trajectory. Both measures were expressed as a percentage of foot length. Measures from limbs with a present first rocker according to kinetic data were compared with limbs with an absent first rocker. A dorsiflexion moment (>0.05 Nm/kg) in the first five per cent of the gait cycle was used to indicate the presence of the first rocker. Results: The PtIC occurred significantly earlier in limbs with a present first rocker (median 9%, IRQ 4) than in those where the first rocker was absent (median 55%, IRQ 24) (between-group difference 45%, p = .018). Roll-back was absent or negligible when the first rocker was present (median 0%, IRQ 0.15) but was significantly greater in those trials where the first rocker was absent
The impact of obesity on plantar pressure and balance ability in children D. Patikas 1,∗ , E. Bilili 1 , E. Simantira 1 , A. Xenofondos 2,4 , D. Metaxiotis 3,4 1
Aristotle University of Thessaloniki, Serres, Greece Aristotle University of Thessaloniki, ELEPAP, Thessaloniki, Greece 3 Papageorgiou General Hospital, ELEPAP, Thessaloniki, Greece 4 Gait Analysis Laboratory, ELEPAP, Thessaloniki, Greece 2
Research question: To examine the differences in plantar pressure and balance ability between children with normal and increased body fat. We tested the effect of visual feedback and base of support during standing balance tasks using instrumented pedobarography. Introduction: Overweight and obese children often experience problems in gait and posture. Pedobarography has been implemented to examine the effect of excessive body weight on foot morphology and biomechanics [1]. However, it is not yet clear to what extent mechanisms that contribute to the ability to balance (proprioception, vision, vestibular system) are influenced by differences in body composition in children. This study was designed to examine the effect of excessive weight on the biomechanical and morphological parameters of children’s feet during static balance tasks. Materials and methods: Thirty-six children (13 girls) were divided depending on their body fat percentage, as estimated by the Jackson & Pollock [2] equation adjusted for age and sex. The overweight-obese (OG) and the control group (CG) were 11.0 ± 2.6 and 10.1 ± 2.7 years old, had 21.2 ± 8.0% and 11.6 ± 6.3% body fat, and 25.5 ± 4.0 and 17.6 ± 1.6 kg/m2 BMI, respectively. Static balance was assessed on one or two feet, with eyes open or closed, while standing on a foot scanner (EPS, COMEX, Athens, Greece) as still as possible. The star excursion balance and functional reach test were assessed as field tests. Level of significance a was set at 0.05. Results: OG had significantly lower medial arch index and larger contact surface than the CG indicating a pes planus. The difference was more prominent when standing on both feet. Variability of the center of pressure on the anterior–posterior and mediolateral axis did not demonstrate any significant differences between the two groups in any of the examined conditions (open/closed eyes vs. standing on left/right/both feet). The star excursion balance tests