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Upper body gait kinematics in children with hemplegic cerebral palsy
S4
Abstracts / Gait & Posture 39S (2014) S1–S141
Fig. 1. Walking speed and walking efficiency under 5 different conditions.
004 Gait responses to modifying the spring stiffness of a dorsiflexion stopped ankle-foot orthosis in a polio survivor with plantar flexor weakness H.E. Ploeger 1,∗ , M.A. Brehm 1,2 , J. Harlaar 2 , Y.L. Kerkum 2 , S.A. Bus 1 , F. Nollet 1 1 Department of Rehabilitation Medicine, Academic Medical Center, University of Amsterdam, The Netherlands 2 Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
Introduction and aim: In patients with post polio syndrome (PPS), gait is frequently hampered by excessive and/or abrupt ankle dorsiflexion, caused by weakness of the plantar flexors. This can lead to instability and fatigue due to a reduced walking efficiency [1]. To provide stability and increase walking efficiency, patients with plantar flexor weakness can be prescribed with a spring-like dorsiflexion stopped ankle-foot orthosis (DS-AFO). In patients with stroke and MS presenting spastic leg paresis, it has been shown that walking with such an AFO can optimize walking efficiency by choosing the correct ankle stiffness [2]. A similar principal might also apply to patients with flaccid paresis. The aim of this study was to evaluate the effect of different degrees of DS-AFO ankle stiffness on walking efficiency and gait biomechanics in patients with PPS and plantar flexor weakness. Patients/materials and methods: One male patient with PPS and mild plantar flexor weakness participated (age: 67 years, MRC score plantar flexors: 4+ , gait pattern: excessive ankle range of motion combined with persistent knee flexion during stance). For this patient a custom made foot part with calf casing was fabricated, in which five interchangeable carbon leaf springs with a different degree of stiffness (k) could be placed (range: k1 : 0.8 Nm/deg to k5 : 7.3 Nm/deg, as measured with the BRUCE device [3]). The patient was first assessed for gait biomechanics (Vicon MX, AMTI force plates) at comfortable speed while walking with the DS-AFO (5 springs, tested in random order). Each measurement started after the patient indicated to be customized to the new spring. After each condition, satisfaction was rated with a visual analogue scale. Subsequently, walking efficiency was assessed (Cosmed) during a 6-min walk test for the most satisfying DS-AFO spring, the stiffest and the most compliant spring. Gait biomechanics and walking efficiency were also assessed for the patients’ own DS-AFO and for walking with shoes alone. Results: The patient rated DS-AFO-k3 (2.5 Nm/deg) as most satisfying: ‘It supported, but did not constrain too much’. Walking with this DS-AFO resulted in the highest comfortable gait speed (10% higher compared to shoes alone) and it increased walking efficiency with 2.5% compared to walking with shoes alone and to walking with his own DS-AFO (Fig. 1). However, most efficient gait was seen with the stiffest spring (k5 = 7.3 Nm/deg): +4.1% compared to walk-
ing with shoes alone. Regarding gait biomechanics, ankle range of motion (range: k1 : 33◦ to k5 : 19◦ ) and ankle power during push-off (range: k1 : 2.1 W/kg to k5 : 1.2 W/kg) reduced with increasing stiffness. Only the three stiffest springs resulted in a decreased knee flexion during terminal stance (all about −4.8◦ ), compared to the two most compliant springs. Discussion and conclusions: The results of this case study indicate that for this patient with PPS and plantar flexor weakness optimizing DS-AFO ankle stiffness was useful for improving gait with respect to walking efficiency. Walking with the stiffest DSAFO (k5 = 7.3) resulted in the most efficient gait, and, although the improvements were small, gait efficiency and reduction of knee flexion seemed to be related. However, the most efficient DS-AFO was not considered the most satisfying DS-AFO. Since plantar flexor weakness from the measured patient was only mild, a high stiffness may not be optimal. This is the first result from an ongoing project; we expect that a broader range in plantar flexor weakness will yield more precise relations on how DS-AFO mechanics and patient characteristics interact towards gait performance. Ultimately, this will serve DS-AFO stiffness selection in patients with PPS. References [1] Brehm MA, et al. Arch Phys Med Rehabil 2006;87:136–40. [2] Bregman DJ, et al. Thesis; 2011, ISBN 978-90-6464-486-3. p. 105–24. [3] Bregman DJ, et al. Gait Posture 2009;30:144–9.
http://dx.doi.org/10.1016/j.gaitpost.2014.04.008 005 Upper body gait kinematics in children with hemplegic cerebral palsy Jacqueline Romkes ∗ , Reinald Brunner, Katrin Schweizer Laboratory for Movement Analysis, University Children’s Hospital Basle, University of Basle, Basle, Switzerland Introduction and aim: A typical gait deviation in children with hemiplegic cerebral palsy (hemi-CP) is toe-walking on the affected side. A common treatment for this gait abnormality is to provide the patient with a hinged ankle foot orthosis (AFO) on the affected leg. Although the upper body of the hemiplegic side is also affected, gait studies on the trunk and arms are scarce [1,2]. The first aim of this study was to investigate the upper body gait kinematics in children with hemi-CP. The second aim was to evaluate how the change from initial toe-contact (barefoot) to a heel-toe gait pattern (shoes and AFO) influences the upper body gait kinematics in children with hemi-CP. Patients/materials and methods: 23 children with hemi-CP and 17 healthy children were included in this retrospective study. All children walked barefoot and the patients also with their shoes and AFO. Inclusion criteria for the patients were initial toe contact during barefoot gait and a heel-toe gait with the AFO. Full-body 3D gait data were collected by a Vicon 460 motion capture system using the Plug in Gait Model [3]. Kinematic movement curves of the pelvis, thorax, shoulder, and elbow were of interest. The 95% confidence intervals (CI) for specific parameters (range of motion (RoM), mean angle, minimum, maximum) were calculated. A parameter of which the CIs within the patients or compared to the control group did not overlap was defined as a clinical relevant difference with 95% probability. Results: ELBOW flexion: The motion curves for the affected side of the patients were shifted towards flexion (Fig. 1). SHOULDER flexion: Maximum and RoM were increased on the unaffected
Abstracts / Gait & Posture 39S (2014) S1–S141
S5
Fig. 1. Results for elbow flexion. An asterisk (*) indicates no overlap with the controls and the unaffected leg.
side compared to the affected side with an AFO, no differences to controls. THORAX tilt: greater RoM for the patients compared to controls. THORAX obliquity: greater RoM on the patients’ affected side compared to controls. THORAX rotation: more internal rotation on the unaffected side and more external rotation on the affected side within patients, with the unaffected side greater than the controls. PELVIC tilt: increased RoM for the patients compared to controls. PELVIC obliquity: within patients, the unaffected side was higher than the affected side. However, both sides were not clinically different from the controls. PELVIC rotation: the affected side of the patients is rotated more externally and the non-affected side more internally for both barefoot and with an AFO. Discussion and conclusions: This study investigated the upper body motion during gait in children with hemi-CP. It also pointed out the clinical relevant differences when compared to a control group. Our results for the shoulder and elbow motion agree with the results from Riad et al. [1]. Although an AFO corrected the pathological toe-walking to a heel-toe gait in the patients, the influences on the upper body kinematics were small. This may be explained by the fact that all children with hemi-CP were experienced users of AFOs. The results contribute to a better understanding of gait deviations in the upper body due to the biomechanics of toe-walking in children with hemi-CP.
References [1] Riad, et al. Gait Posture 2011;33(1):48–53. [2] Meyns, et al. Res Dev Disabil 2011;32(5):1957–64. [3] Romkes, et al. J Pediatr Orthop B 2007;16:175–80.
http://dx.doi.org/10.1016/j.gaitpost.2014.04.009 006 Stumble recovery kinematics for KAFO users Edward D. Lemaire 1,2,∗ , Whitney Montgomery 3 1
The Ottawa Hospital Research Institute, Canada University of Ottawa, Faculty of Medicine, Canada 3 University of Ottawa, School of Human Kinetics, Canada
Ottawalk-speed (OWS) knee joint [1], for the purpose of examining stumble recovery with this KAFO. Patients/materials and methods: Three male KAFO users with mild knee extensor weakness, from traumatic femoral nerve injury were recruited (51–59 years) and fit with a custom OWS KAFO. After setting the OWS angular velocity threshold, training and adequate accommodation time was provided (Fig. 1). A custom designed stumble event was created for “The Park” CAREN-Extended application. This “split-speed perturbation” speeds up one treadmill belt and slows down the other belt, creating a stumble that resulted in a flexed knee landing when tested on able-bodied individuals. OWS participants completed several accommodation trials to adjust to the virtual environment. Accommodation trials did not exceed 80 m. OWS testing consisted of five 100 m walking trials in “The Park”, in self-paced mode. All trials began and ended with a level platform condition and contained three of uphill, downhill, rolling hills or uneven simulated surface conditions. Participants were informed that stumble perturbations would be randomly applied. The operator adjusted the treadmill perturbation length (s) to accommodate individual walking speeds. Kinematic data were collected at 120 Hz using a 12 camera Vicon system. Five stumble trials were collected. 6 DoF marker set data were transferred to Visual3D for post processing. Results: The split-speed perturbation produced a stumble but did not cause knee collapse. Instead, a straight-legged response was observed. Though the stumble produced 1–2 deg more knee flexion at foot strike during recovery, compared to level walking, the knee was quickly extended and remained straight in stance. Except for one trial, maximum knee flexion in early stance was equal to recovery foot strike angles. All participants used at least one handrail for support before, following, or during the perturbation. No stumbles occurred for the other conditions. Discussion and conclusions: OWS-KAFO users with mild knee extensor weakness used a straight-legged response for recovery following a perturbation that produced bent-knee landing in ablebodied participants. Removing handrails may result in a different recovery strategy.
2
Introduction and aim: Recovering from a stumble is an essential skill for safe and confident ambulation. For people with knee extensor weakness, walking with a knee ankle foot orthosis (KAFO) can provide sufficient control and support. However, new orthoses can allow free knee motion during walking but provide knee flexion resistance during knee collapse. This study used the CARENExtended VR environment to create a stumble for people using the
Reference [1] Lemaire ED, Goudreau L, Yakimovich T, Kofman J. Angular-velocity control approach for stance-control orthoses. IEEE Trans Neural Syst Rehabil Eng 2009;17(October (5)):497–503.
http://dx.doi.org/10.1016/j.gaitpost.2014.04.010
Abstracts / Gait & Posture 39S (2014) S1–S141
Fig. 1. Walking speed and walking efficiency under 5 different conditions.
004 Gait responses to modifying the spring stiffness of a dorsiflexion stopped ankle-foot orthosis in a polio survivor with plantar flexor weakness H.E. Ploeger 1,∗ , M.A. Brehm 1,2 , J. Harlaar 2 , Y.L. Kerkum 2 , S.A. Bus 1 , F. Nollet 1 1 Department of Rehabilitation Medicine, Academic Medical Center, University of Amsterdam, The Netherlands 2 Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
Introduction and aim: In patients with post polio syndrome (PPS), gait is frequently hampered by excessive and/or abrupt ankle dorsiflexion, caused by weakness of the plantar flexors. This can lead to instability and fatigue due to a reduced walking efficiency [1]. To provide stability and increase walking efficiency, patients with plantar flexor weakness can be prescribed with a spring-like dorsiflexion stopped ankle-foot orthosis (DS-AFO). In patients with stroke and MS presenting spastic leg paresis, it has been shown that walking with such an AFO can optimize walking efficiency by choosing the correct ankle stiffness [2]. A similar principal might also apply to patients with flaccid paresis. The aim of this study was to evaluate the effect of different degrees of DS-AFO ankle stiffness on walking efficiency and gait biomechanics in patients with PPS and plantar flexor weakness. Patients/materials and methods: One male patient with PPS and mild plantar flexor weakness participated (age: 67 years, MRC score plantar flexors: 4+ , gait pattern: excessive ankle range of motion combined with persistent knee flexion during stance). For this patient a custom made foot part with calf casing was fabricated, in which five interchangeable carbon leaf springs with a different degree of stiffness (k) could be placed (range: k1 : 0.8 Nm/deg to k5 : 7.3 Nm/deg, as measured with the BRUCE device [3]). The patient was first assessed for gait biomechanics (Vicon MX, AMTI force plates) at comfortable speed while walking with the DS-AFO (5 springs, tested in random order). Each measurement started after the patient indicated to be customized to the new spring. After each condition, satisfaction was rated with a visual analogue scale. Subsequently, walking efficiency was assessed (Cosmed) during a 6-min walk test for the most satisfying DS-AFO spring, the stiffest and the most compliant spring. Gait biomechanics and walking efficiency were also assessed for the patients’ own DS-AFO and for walking with shoes alone. Results: The patient rated DS-AFO-k3 (2.5 Nm/deg) as most satisfying: ‘It supported, but did not constrain too much’. Walking with this DS-AFO resulted in the highest comfortable gait speed (10% higher compared to shoes alone) and it increased walking efficiency with 2.5% compared to walking with shoes alone and to walking with his own DS-AFO (Fig. 1). However, most efficient gait was seen with the stiffest spring (k5 = 7.3 Nm/deg): +4.1% compared to walk-
ing with shoes alone. Regarding gait biomechanics, ankle range of motion (range: k1 : 33◦ to k5 : 19◦ ) and ankle power during push-off (range: k1 : 2.1 W/kg to k5 : 1.2 W/kg) reduced with increasing stiffness. Only the three stiffest springs resulted in a decreased knee flexion during terminal stance (all about −4.8◦ ), compared to the two most compliant springs. Discussion and conclusions: The results of this case study indicate that for this patient with PPS and plantar flexor weakness optimizing DS-AFO ankle stiffness was useful for improving gait with respect to walking efficiency. Walking with the stiffest DSAFO (k5 = 7.3) resulted in the most efficient gait, and, although the improvements were small, gait efficiency and reduction of knee flexion seemed to be related. However, the most efficient DS-AFO was not considered the most satisfying DS-AFO. Since plantar flexor weakness from the measured patient was only mild, a high stiffness may not be optimal. This is the first result from an ongoing project; we expect that a broader range in plantar flexor weakness will yield more precise relations on how DS-AFO mechanics and patient characteristics interact towards gait performance. Ultimately, this will serve DS-AFO stiffness selection in patients with PPS. References [1] Brehm MA, et al. Arch Phys Med Rehabil 2006;87:136–40. [2] Bregman DJ, et al. Thesis; 2011, ISBN 978-90-6464-486-3. p. 105–24. [3] Bregman DJ, et al. Gait Posture 2009;30:144–9.
http://dx.doi.org/10.1016/j.gaitpost.2014.04.008 005 Upper body gait kinematics in children with hemplegic cerebral palsy Jacqueline Romkes ∗ , Reinald Brunner, Katrin Schweizer Laboratory for Movement Analysis, University Children’s Hospital Basle, University of Basle, Basle, Switzerland Introduction and aim: A typical gait deviation in children with hemiplegic cerebral palsy (hemi-CP) is toe-walking on the affected side. A common treatment for this gait abnormality is to provide the patient with a hinged ankle foot orthosis (AFO) on the affected leg. Although the upper body of the hemiplegic side is also affected, gait studies on the trunk and arms are scarce [1,2]. The first aim of this study was to investigate the upper body gait kinematics in children with hemi-CP. The second aim was to evaluate how the change from initial toe-contact (barefoot) to a heel-toe gait pattern (shoes and AFO) influences the upper body gait kinematics in children with hemi-CP. Patients/materials and methods: 23 children with hemi-CP and 17 healthy children were included in this retrospective study. All children walked barefoot and the patients also with their shoes and AFO. Inclusion criteria for the patients were initial toe contact during barefoot gait and a heel-toe gait with the AFO. Full-body 3D gait data were collected by a Vicon 460 motion capture system using the Plug in Gait Model [3]. Kinematic movement curves of the pelvis, thorax, shoulder, and elbow were of interest. The 95% confidence intervals (CI) for specific parameters (range of motion (RoM), mean angle, minimum, maximum) were calculated. A parameter of which the CIs within the patients or compared to the control group did not overlap was defined as a clinical relevant difference with 95% probability. Results: ELBOW flexion: The motion curves for the affected side of the patients were shifted towards flexion (Fig. 1). SHOULDER flexion: Maximum and RoM were increased on the unaffected
Abstracts / Gait & Posture 39S (2014) S1–S141
S5
Fig. 1. Results for elbow flexion. An asterisk (*) indicates no overlap with the controls and the unaffected leg.
side compared to the affected side with an AFO, no differences to controls. THORAX tilt: greater RoM for the patients compared to controls. THORAX obliquity: greater RoM on the patients’ affected side compared to controls. THORAX rotation: more internal rotation on the unaffected side and more external rotation on the affected side within patients, with the unaffected side greater than the controls. PELVIC tilt: increased RoM for the patients compared to controls. PELVIC obliquity: within patients, the unaffected side was higher than the affected side. However, both sides were not clinically different from the controls. PELVIC rotation: the affected side of the patients is rotated more externally and the non-affected side more internally for both barefoot and with an AFO. Discussion and conclusions: This study investigated the upper body motion during gait in children with hemi-CP. It also pointed out the clinical relevant differences when compared to a control group. Our results for the shoulder and elbow motion agree with the results from Riad et al. [1]. Although an AFO corrected the pathological toe-walking to a heel-toe gait in the patients, the influences on the upper body kinematics were small. This may be explained by the fact that all children with hemi-CP were experienced users of AFOs. The results contribute to a better understanding of gait deviations in the upper body due to the biomechanics of toe-walking in children with hemi-CP.
References [1] Riad, et al. Gait Posture 2011;33(1):48–53. [2] Meyns, et al. Res Dev Disabil 2011;32(5):1957–64. [3] Romkes, et al. J Pediatr Orthop B 2007;16:175–80.
http://dx.doi.org/10.1016/j.gaitpost.2014.04.009 006 Stumble recovery kinematics for KAFO users Edward D. Lemaire 1,2,∗ , Whitney Montgomery 3 1
The Ottawa Hospital Research Institute, Canada University of Ottawa, Faculty of Medicine, Canada 3 University of Ottawa, School of Human Kinetics, Canada
Ottawalk-speed (OWS) knee joint [1], for the purpose of examining stumble recovery with this KAFO. Patients/materials and methods: Three male KAFO users with mild knee extensor weakness, from traumatic femoral nerve injury were recruited (51–59 years) and fit with a custom OWS KAFO. After setting the OWS angular velocity threshold, training and adequate accommodation time was provided (Fig. 1). A custom designed stumble event was created for “The Park” CAREN-Extended application. This “split-speed perturbation” speeds up one treadmill belt and slows down the other belt, creating a stumble that resulted in a flexed knee landing when tested on able-bodied individuals. OWS participants completed several accommodation trials to adjust to the virtual environment. Accommodation trials did not exceed 80 m. OWS testing consisted of five 100 m walking trials in “The Park”, in self-paced mode. All trials began and ended with a level platform condition and contained three of uphill, downhill, rolling hills or uneven simulated surface conditions. Participants were informed that stumble perturbations would be randomly applied. The operator adjusted the treadmill perturbation length (s) to accommodate individual walking speeds. Kinematic data were collected at 120 Hz using a 12 camera Vicon system. Five stumble trials were collected. 6 DoF marker set data were transferred to Visual3D for post processing. Results: The split-speed perturbation produced a stumble but did not cause knee collapse. Instead, a straight-legged response was observed. Though the stumble produced 1–2 deg more knee flexion at foot strike during recovery, compared to level walking, the knee was quickly extended and remained straight in stance. Except for one trial, maximum knee flexion in early stance was equal to recovery foot strike angles. All participants used at least one handrail for support before, following, or during the perturbation. No stumbles occurred for the other conditions. Discussion and conclusions: OWS-KAFO users with mild knee extensor weakness used a straight-legged response for recovery following a perturbation that produced bent-knee landing in ablebodied participants. Removing handrails may result in a different recovery strategy.
2
Introduction and aim: Recovering from a stumble is an essential skill for safe and confident ambulation. For people with knee extensor weakness, walking with a knee ankle foot orthosis (KAFO) can provide sufficient control and support. However, new orthoses can allow free knee motion during walking but provide knee flexion resistance during knee collapse. This study used the CARENExtended VR environment to create a stumble for people using the
Reference [1] Lemaire ED, Goudreau L, Yakimovich T, Kofman J. Angular-velocity control approach for stance-control orthoses. IEEE Trans Neural Syst Rehabil Eng 2009;17(October (5)):497–503.
http://dx.doi.org/10.1016/j.gaitpost.2014.04.010