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Foot loading patterns in children after Ponseti clubfoot treatment
Abstracts / Clinical Biomechanics 23 (2008) 662–720
tered from m. tibialis ant. (TA), m. peronaeus (P), vastus medialis of the gastrocnemius (MG) and from the m. glutaeus medius (GM). Pedar signal was used for trigger signal in EMG. All tests have been performed with normal running shoes (NRS) and USC (Masai Barefoot Technology, MBT). Before the tests, subjects had to undergo a special training protocol to get used to the USC.
Results Significant differences have been found between NRS and USC. In summary with the USC the beginning of contact in the forefoot and the end of contact in the heel occured earlier. The contact time was longer in the forefoot and heel. Peak pressure and pressure integral have been increased in the midfoot and decreased in the forefoot. Speed and slope had a significant influence of the absolute values, but not on the differences between NRS and USC. EMG data have been normalized, rectified, smoothed and averaged over 15 steps for each condition. For calculation, we used peak voltage (PV), averaged rectified voltage (ARV) and time bevor peak (TBP). Only for the MG, significant differences had been found. Especially between walking (6 and 8 km/h) and running (10 and 14 km/h) PV and MV increased, whereas TBP decreased about 50% during running. PV decreased during running with decreasing slope. This pattern has been found with the USC as well as with NRS. Conclusion Walking and running downhill are different movement patterns concerning the load on passive structures. Therefore different muscles have to change their activity. In the muscles that had been examined, we only found changes in activity patterns with the MG, where speed had more influence than slope. Using an USC leads to a shift of maximum pressure but no difference could be found in EMG activity in the muscles that had been examined. Speed and slope showed changes in pressure distribution with increasing pressure especially in the heel region with increasing speed and slope. Walking and running with an USC leads to a shift of pressure from forefoot and heel to midfoot compared with NRS. In EMG activity only MG showed different patterns according to speed and slope, but not between USC and NRS. This could be interpreted as an attempt to control knee joint stability. We conclude that compared to NRS walking and running downhill with an USC is less stressful for the peak pressure area with the same activity pattern of the muscles.
665
Nigg, B.M., 2004. Effect of an Unstable Shoe Construction on Lower Extremity Gait Characteristics. University of Calgary. Romkes, J., Rudman, C., Brunner, R., 2006. Changes in gait and EMG when walking with the masai barefoot technique. Clinical Biomechanics 21, 75–81. doi:10.1016/j.clinbiomech.2008.03.005
Foot loading patterns in children after Ponseti clubfoot treatment Kerstin Bosch a, Stephanie Bo¨hm b, Marc F. Sinclair b, Dieter Rosenbaum a a
Movement Analysis Laboratory, Orthopaedic Department, University Hospital Muenster, Germany b Children’s Hospital Altona, Orthopaedic Department, Hamburg, Germany
Introduction The conservative Ponseti treatment for congenital clubfoot is already known since 1963 but it did not gain attention until 1995 (Ponseti, 2005). With a weekly modified cast treatment starting from birth – often combined with Achilles tenotomy – and a subsequent bracing period the treated foot is expected to become strong, flexible, pain free and to allow a normal life (Ponseti, 2005). The aim of the present study is to evaluate if there are differences in foot loading characteristics in clubfeet after Ponseti treatment in comparison to normal foot loading characteristics in childhood. Methods and materials Dynamic foot pressure measurement was analysed in 20 children (average age 3 years) with congenital clubfoot after 33 months of Ponseti treatment and in a healthy control group (20 children; average age 3 years). The children walked barefoot with self-selected speed over the emed ST 4 platform (Novel). As dynamic parameters, the peak
References Minetti, A.E. et al., 2002. Energy cost of walking and running at extreme uphill and downhill slopes. Journal of Applied Physiology 93, 1039– 1046.
Fig. 1. Pressure patterns of a child with a treated clubfoot on the right and non-affected foot on the left.
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Abstracts / Clinical Biomechanics 23 (2008) 662–720
MF CA FTI PP
Ponseti treatment. The comparison within the clubfoot sample showed a more dynamic roll-over process for the healthy foot, which could be demonstrated by the PP differences. Long-term results will be further evaluated. Acknowledgements Thanks are due to the children and their families.
Fig. 2. Significant results of the clubfeet in comparison to normal feet.
References pressure (PP), maximum force (MF), impulse (FTI) and contact area (CA) were evaluated. CA, MF and FTI were normalized to bodyweight or foot size. The foot was divided into 10 regions of interest. The clubfoot sample was compared with the healthy control groups and furthermore in 12 children with unilateral clubfoot the healthy and affected feet were intra-individually compared. For statistical analyses the Mann–Whitney U-test was used for unpaired and the Wilcoxon Test for paired comparison (P < 0.05) (see Figs. 1 and 2). Results and discussion The comparison between clubfeet and controls showed significantly lower values for the clubfoot sample for normalized MF, CA and FTI in almost every region except for the midfoot where significantly higher values could be observed. The larger midfoot contact area also caused higher values of MF and FTI in this area. The reason for the higher CA values of the midfoot is not easily understood and has to be discussed with clinical information. Furthermore, the absolute PP values showed no significant differences regarding the midfoot region and the lateral metatarsals. The absence of significant differences in the midfoot demonstrates the development towards normal foot loading characteristics under that region. The heel regions had a lower PP in clubfeet than in controls, thus confirming earlier findings (Cooper et al., 1995). The lower values can be attributed to the delayed development of muscular activity especially of the gastrocnemius in clubfeet. The intra-individual comparison within the clubfoot sample showed significantly higher PP values for the nonaffected side. This applied for the total foot as well as for the hallux, the medial heel and the lateral toes. The higher PP values indicate a more dynamic roll-over process for the non-affected side.
Cooper, S. et al., 1995. JBJS 77-A (10), 1477–1489. Ponseti, I., 2005. Ponseti Management. Clubfoot. doi:10.1016/j.clinbiomech.2008.03.006
Effective orthotic therapy for the painful cavus foot: A randomized controlled trial Joshua Burns a, Jack Crosbie b, Adrienne Hunt b, Robert Ouvrier a a
Institute for Neuromuscular Research, Children’s Hospital at Westmead, NSW, Australia b School of Physiotherapy, University of Sydney, NSW, Australia
Introduction Pes cavus is a multi-planar foot deformity characterized by an excessively high medial longitudinal arch. It commonly features a varus position of the calcaneus, plantar flexed first metatarsal, adducted forefoot and clawing of the digits (Fig. 1). Foot pain affects 60% of individuals with a cavus foot type, which is thought to result from abnormal plantar pressure distribution (Burns et al., 2005). Preliminary field work suggests that custom foot orthoses may be a worthwhile treatment option for patients with painful pes cavus, by way of reducing and redistributing plantar pressure (Burns, 2004).
Conclusion In spite of an overall good clinical outcome, the present results revealed significant differences of foot loading patterns between controls and clubfeet after 33 months of
Fig. 1. Typical cavus foot type.
tered from m. tibialis ant. (TA), m. peronaeus (P), vastus medialis of the gastrocnemius (MG) and from the m. glutaeus medius (GM). Pedar signal was used for trigger signal in EMG. All tests have been performed with normal running shoes (NRS) and USC (Masai Barefoot Technology, MBT). Before the tests, subjects had to undergo a special training protocol to get used to the USC.
Results Significant differences have been found between NRS and USC. In summary with the USC the beginning of contact in the forefoot and the end of contact in the heel occured earlier. The contact time was longer in the forefoot and heel. Peak pressure and pressure integral have been increased in the midfoot and decreased in the forefoot. Speed and slope had a significant influence of the absolute values, but not on the differences between NRS and USC. EMG data have been normalized, rectified, smoothed and averaged over 15 steps for each condition. For calculation, we used peak voltage (PV), averaged rectified voltage (ARV) and time bevor peak (TBP). Only for the MG, significant differences had been found. Especially between walking (6 and 8 km/h) and running (10 and 14 km/h) PV and MV increased, whereas TBP decreased about 50% during running. PV decreased during running with decreasing slope. This pattern has been found with the USC as well as with NRS. Conclusion Walking and running downhill are different movement patterns concerning the load on passive structures. Therefore different muscles have to change their activity. In the muscles that had been examined, we only found changes in activity patterns with the MG, where speed had more influence than slope. Using an USC leads to a shift of maximum pressure but no difference could be found in EMG activity in the muscles that had been examined. Speed and slope showed changes in pressure distribution with increasing pressure especially in the heel region with increasing speed and slope. Walking and running with an USC leads to a shift of pressure from forefoot and heel to midfoot compared with NRS. In EMG activity only MG showed different patterns according to speed and slope, but not between USC and NRS. This could be interpreted as an attempt to control knee joint stability. We conclude that compared to NRS walking and running downhill with an USC is less stressful for the peak pressure area with the same activity pattern of the muscles.
665
Nigg, B.M., 2004. Effect of an Unstable Shoe Construction on Lower Extremity Gait Characteristics. University of Calgary. Romkes, J., Rudman, C., Brunner, R., 2006. Changes in gait and EMG when walking with the masai barefoot technique. Clinical Biomechanics 21, 75–81. doi:10.1016/j.clinbiomech.2008.03.005
Foot loading patterns in children after Ponseti clubfoot treatment Kerstin Bosch a, Stephanie Bo¨hm b, Marc F. Sinclair b, Dieter Rosenbaum a a
Movement Analysis Laboratory, Orthopaedic Department, University Hospital Muenster, Germany b Children’s Hospital Altona, Orthopaedic Department, Hamburg, Germany
Introduction The conservative Ponseti treatment for congenital clubfoot is already known since 1963 but it did not gain attention until 1995 (Ponseti, 2005). With a weekly modified cast treatment starting from birth – often combined with Achilles tenotomy – and a subsequent bracing period the treated foot is expected to become strong, flexible, pain free and to allow a normal life (Ponseti, 2005). The aim of the present study is to evaluate if there are differences in foot loading characteristics in clubfeet after Ponseti treatment in comparison to normal foot loading characteristics in childhood. Methods and materials Dynamic foot pressure measurement was analysed in 20 children (average age 3 years) with congenital clubfoot after 33 months of Ponseti treatment and in a healthy control group (20 children; average age 3 years). The children walked barefoot with self-selected speed over the emed ST 4 platform (Novel). As dynamic parameters, the peak
References Minetti, A.E. et al., 2002. Energy cost of walking and running at extreme uphill and downhill slopes. Journal of Applied Physiology 93, 1039– 1046.
Fig. 1. Pressure patterns of a child with a treated clubfoot on the right and non-affected foot on the left.
666
Abstracts / Clinical Biomechanics 23 (2008) 662–720
MF CA FTI PP
Ponseti treatment. The comparison within the clubfoot sample showed a more dynamic roll-over process for the healthy foot, which could be demonstrated by the PP differences. Long-term results will be further evaluated. Acknowledgements Thanks are due to the children and their families.
Fig. 2. Significant results of the clubfeet in comparison to normal feet.
References pressure (PP), maximum force (MF), impulse (FTI) and contact area (CA) were evaluated. CA, MF and FTI were normalized to bodyweight or foot size. The foot was divided into 10 regions of interest. The clubfoot sample was compared with the healthy control groups and furthermore in 12 children with unilateral clubfoot the healthy and affected feet were intra-individually compared. For statistical analyses the Mann–Whitney U-test was used for unpaired and the Wilcoxon Test for paired comparison (P < 0.05) (see Figs. 1 and 2). Results and discussion The comparison between clubfeet and controls showed significantly lower values for the clubfoot sample for normalized MF, CA and FTI in almost every region except for the midfoot where significantly higher values could be observed. The larger midfoot contact area also caused higher values of MF and FTI in this area. The reason for the higher CA values of the midfoot is not easily understood and has to be discussed with clinical information. Furthermore, the absolute PP values showed no significant differences regarding the midfoot region and the lateral metatarsals. The absence of significant differences in the midfoot demonstrates the development towards normal foot loading characteristics under that region. The heel regions had a lower PP in clubfeet than in controls, thus confirming earlier findings (Cooper et al., 1995). The lower values can be attributed to the delayed development of muscular activity especially of the gastrocnemius in clubfeet. The intra-individual comparison within the clubfoot sample showed significantly higher PP values for the nonaffected side. This applied for the total foot as well as for the hallux, the medial heel and the lateral toes. The higher PP values indicate a more dynamic roll-over process for the non-affected side.
Cooper, S. et al., 1995. JBJS 77-A (10), 1477–1489. Ponseti, I., 2005. Ponseti Management. Clubfoot. doi:10.1016/j.clinbiomech.2008.03.006
Effective orthotic therapy for the painful cavus foot: A randomized controlled trial Joshua Burns a, Jack Crosbie b, Adrienne Hunt b, Robert Ouvrier a a
Institute for Neuromuscular Research, Children’s Hospital at Westmead, NSW, Australia b School of Physiotherapy, University of Sydney, NSW, Australia
Introduction Pes cavus is a multi-planar foot deformity characterized by an excessively high medial longitudinal arch. It commonly features a varus position of the calcaneus, plantar flexed first metatarsal, adducted forefoot and clawing of the digits (Fig. 1). Foot pain affects 60% of individuals with a cavus foot type, which is thought to result from abnormal plantar pressure distribution (Burns et al., 2005). Preliminary field work suggests that custom foot orthoses may be a worthwhile treatment option for patients with painful pes cavus, by way of reducing and redistributing plantar pressure (Burns, 2004).
Conclusion In spite of an overall good clinical outcome, the present results revealed significant differences of foot loading patterns between controls and clubfeet after 33 months of
Fig. 1. Typical cavus foot type.