|Year : 2021 | Volume
| Issue : 2 | Page : 74-80
Sagittal plane gait analysis in children with cerebral palsy spastic diplegia with crouch gait: A retrospective observational study
Sneha Saravanakumar, Anitha Kumaravelan, R Ravindran
Department of Physiotherapy, All India Institute of Physical Medicine and Rehabilitation, Mumbai, Maharashtra, India
|Date of Submission||25-Dec-2020|
|Date of Decision||12-Dec-2021|
|Date of Acceptance||13-Dec-2021|
|Date of Web Publication||15-Feb-2022|
Dr. Sneha Saravanakumar
13-302, Sector 7, C G S Colony, Antophill, Mumbai - 400 037, Maharashtra
Source of Support: None, Conflict of Interest: None
PURPOSE: The purpose of this study was to understand the pathomechanics of crouch gait by analyzing sagittal plane kinematics and kinetics of gait in children with spastic diplegia.
RELEVANCE: This study would be instrumental in planning treatment strategy considering kinematics and kinetics.
PARTICIPANTS: Twenty-six children with cerebral palsy spastic diplegia (Gross motor function classification system [GMFCS] level 2) with crouch had undergone gait analysis during the period January 2015–December 2016, of which 14 children were included in the study after excluding 12 children due to noncompliance of inclusion/exclusion criteria and missing technical data. The mean age of the population was 12.29 ± 1.94 years.
METHODOLOGY: This study being a retrospective study, waiver of consent was obtained from the ethics committee. Sagittal plane kinematic and kinetic data of bilateral hip, knee, and ankle were extracted from the gait laboratory. Mean and standard deviation was calculated for cadence, stance, and swing period percentage of the gait cycle of each limb. Graphical representation of mean was done to describe the phases of the gait cycle. A normative gait cycle graph was used as a reference, and deviations were analyzed.
RESULTS AND CONCLUSION: Ankle, knee, and hip remained in excessive flexion throughout the gait cycle. Excursion at all joints was reduced, especially at the knee joint throughout the gait cycle. Extension moment and abnormal power generation and absorption were observed at all joints throughout the stance phase to prevent collapse and sustain erect posture. Hence, the functional objectives of limb stability in the sagittal plane were fulfilled. This further helped in accomplishing the task of weight acceptance and single stance in the stance phase. In the swing phase, all joints were in excessive flexion, however, the task of limb advancement was accomplished
Keywords: Cerebral palsy, crouch gait, gait analysis, spastic diplegia
|How to cite this article:|
Saravanakumar S, Kumaravelan A, Ravindran R. Sagittal plane gait analysis in children with cerebral palsy spastic diplegia with crouch gait: A retrospective observational study. Physiother - J Indian Assoc Physiother 2021;15:74-80
|How to cite this URL:|
Saravanakumar S, Kumaravelan A, Ravindran R. Sagittal plane gait analysis in children with cerebral palsy spastic diplegia with crouch gait: A retrospective observational study. Physiother - J Indian Assoc Physiother [serial online] 2021 [cited 2022 May 21];15:74-80. Available from: https://www.pjiap.org/text.asp?2021/15/2/74/337724
| Introduction|| |
Cerebral palsy (CP) describes a group of permanent disorders of the development of movement and posture, causing activity limitation that is attributed to nonprogressive disturbances that occurred in the developing fetal or infant brain. This type of injury to the neurologic system commonly results in abnormal motor control with associated delay in the onset of walking and an abnormal gait pattern.
The gait cycle can be subdivided into the stance and swing phases to fulfill the functional objective of weight acceptance, single-limb support, and limb advancement.
Based on Sutherland and David's classification of gait abnormalities in CP, Rodda and Graham proposed a classification for children with spastic CP based on sagittal plane kinematics. Four main groups were identified, i.e., true equinus, jump gait, apparent equinus, and crouch gait. The natural history of gait pattern changes in spastic diplegia and is a transition from toe walking to progressive hip knee flexion and eventually to crouch gait. Crouch gait is characterized by excessive knee flexion in the stance. This has been attributed to an adolescent growth spurt and progressive lever arm dysfunction.
Clinical gait analysis aims to identify the deviation in the gait. Children with CP often show subtle changes with intervention, and it is, therefore, important to use instruments with high inter-rater and test–retest reliability. Gait analysis provides detailed information on four main types of data recorded simultaneously: spatiotemporal, kinematics, kinetics, and electromyography data.
Several studies are explaining the kinematics in crouch gait, however, there are very few studies explaining the kinetics in crouch gait. Crouch gait presents with lever arm dysfunction which is related to the length and height of the bone and hence anthropometric measurements of children. Furthermore, large differences were noted in anthropometric measurements in different ethnic groups. As most of the studies are done in American and European populations and there is a scarcity of literature available about gait in the Indian population with CP with crouch gait, hence it is worthwhile knowing the kinetic and kinematic changes in gait in this population which would further help in planning treatment strategies.
Aim and objective of the study
We aimed to observe the sagittal plane kinematics and kinetics at the hip, knee, and ankle in children with CP spastic diplegia with crouch gait.
| Methodology|| |
This study is a retrospective, record-based observational study done in the physiotherapy department of a tertiary health care center. This study was exempted from the institutional ethics committee approval due to its retrospective design. The sample was retrieved from children with CP spastic diplegia who underwent gait analysis in the period from January 2015 to December 2016.
Children with CP spastic diplegia who had undergone gait analysis in the period between January 2015 and December 2016 and children with crouch gait with GMFCS level 2 including both males and females in the age group between 6 and 15 years were included in this study. Children with other types of CP (dyskinetic, ataxia, and hypotonia), children with a history of medical management for spasticity like phenol or botulinum toxin injection, and children with any history of surgery were excluded from this study.
Gait analysis was performed using BTS Smart-D Gait and motion analysis system, Italy (BTS Bioengineering, BTS S.p.A., Italy). Data were acquired using BTS Smart Capture software, and analysis was done using BTS Smart Analyzer software. Davis protocol marker placement procedure was used for all the subjects included in this study.
After the initial screening of the register of the gait and motion analysis laboratory, 26 children with CP spastic diplegia were identified to have undergone gait analysis during the period January 2015 and December 2016. Out of these 26 children, 12 were excluded due to not fitting the inclusion and exclusion criteria (overage – 3, postoperation/injection – 2, and incomplete gait analysis – 7). Hence, 14 children who fulfilled the inclusion and exclusion criteria and whose data were full were included in this retrospective study. The kinematic and kinetic raw data of the included children were extracted from the gait analysis system. In sagittal plane kinematic data, the dorsiflexion/plantar flexion angles of the ankle joint and flexion/extension angles (degrees) of the knee and hip joints of the entire gait cycle were extracted. In kinetic data, the dorsiflexion/plantarflexion moment (Nm/Kg) at the ankle joint and flexion/extension moments of the knee and hip joints and their respective power (W/Kg) generated or absorbed for the entire gait cycle were extracted. The extracted data were tabulated and descriptive statistics were used to describe the observations. The normative data presented in the graphs were from a group of normative adult values obtained from the gait analysis laboratory from an unpublished study done by the third author of this study.
Mean and standard deviation (SD) was used to describe the characteristics of the sample.
| Results|| |
The complete data of 14 children with CP spastic diplegia with crouch gait having a mean age of 12.29 years and SD of 1.94 were included in this study. The sample consisted of 10 male and 4 female children who had undergone gait analysis in the study period.
[Table 1] shows the temporospatial characteristics of the 14 children with CP spastic diplegia with crouch gait. It shows the mean cadence and the stance and swing period percentage for both right and left legs in a complete gait cycle. [Table 2] mentions the maximum and minimum values of ROM in each joint during the entire gait cycle and shows the excursion at each joint in comparison to the normative values. [Table 3] shows the kinetic data, i.e., maximum moment and power at various phases of the gait cycle. Each graph [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9] has three waveforms with three distinct colours. Gray waveform represents the mean of normative data with SD ±1. Green and red color waveform represents the mean of raw data of right and left sides, respectively, in children with spastic diplegia.
|Table 1: Cadence and percentage of stance and swing periods found in the sample of the study|
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|Table 2: Sagittal plane kinematics in the children with cerebral palsy spastic diplegia with crouch gait (n=14)|
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|Table 3: Mean and standard deviation values of the maximum moment and maximum power in various phases of gait cycle|
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|Figure 4: Mean sagittal plane kinetic (moment) values at the ankle joint|
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| Discussion|| |
To understand pathological gait, normal gait is explained in [Table 4], interlinking periods, phases, functional objectives of each phase, and tasks eventually performed.
The normal stance period starts with the task of weight acceptance which is the most demanding task in the gait cycle. Three functional patterns are needed: shock absorption, initial limb stability, and the preservation of progression. In this task, two phases are involved initial contact and loading response. At initial contact, floor contact is made with a heel, and the knee is in extension. The main function at initial contact is limb stability.
In loading response, body weight is transferred onto the forward leg using the heel as the rocker. The function of this phase is shock absorption by knee flexion and preservation of progression using a rocker. The weight acceptance task is followed by the single-limb support task. In this task, one limb is responsible for supporting body weight in both sagittal and coronal planes while progression is continued. Mid-stance and terminal stance are involved in accomplishing the task of single-limb support.
In the mid-stance period, the ankle rocker works to get body weight aligned over the forefoot while the opposite leg is off the ground. The knee is the basic determinant of limb stability and has the functional obligation of maintaining extensor stability. Furthermore, the hip remains in extension. This further helps in supporting body weight in the sagittal and coronal planes.
In the terminal stance period, forefoot rocker works and aligns the body weight ahead of the forefoot and hip and knee continue to remain in extension, both these features much necessary for progression to happen. The single-limb support task is followed by the limb advancement task. In the preswing phase, the main action is weight release from the stance limb and weight transfer to the swing limb and exhibits increased ankle plantarflexion, greater knee flexion, and loss of hip extension. It is the last double support phase of the gait cycle and serves the function of limb advancement. In the initial swing, the limb is advanced by hip flexion and knee flexion, and the foot is lifted. In the mid-swing phase, there is an advancement of the limb anterior to the body weight. In the end, in terminal swing, limb advancement is completed as the tibial shank moves ahead of the thigh.
Along with the abovementioned kinematics and functional objectives of different phases, it is equally important to understand the interpretation of moments of force and power for better understanding. Active internal moments are generated by muscular contraction (concentric, eccentric, or isometric). External moments are generally due to gravitational forces. Contraction of flexor muscle generates an internal flexor moment. When a muscle is contracting concentrically, power is generated. If muscle contracts eccentrically, it absorbs power. If muscle contracts isometrically, no power exchange takes place.
In children with CP spastic diplegia, the below discussion is based on the results as mentioned above.
At initial 0%–10% of gait cycle, at initial contact (0% of the gait cycle), ankle remains in dorsiflexion [Figure 1] and [Table 2] and the hip and knee are in excessive flexion [Figure 2] and [Figure 3]. Extensor moment at the ankle, knee, and hip [Figure 4], [Figure 5], [Figure 6] and [Table 3] along with abnormal power absorption at ankle A1 [Figure 7] and knee K1 [Figure 8] and [Table 3] is observed. This extensor moment and absorption of power at all joints suggest that to provide the function of stability and avoid buckling, the eccentric activity of the extensor group of muscles is observed.
In this most demanding task of weight acceptance due to the absence of heel rocker and presence of excessive knee flexion, the other two functions, shock absorption and preservation of progression, may be altered.
Between 10% and 30% of the gait cycle, the second rocker or the ankle rocker [Figure 1] (the forward translation of tibia at the ankle joint) takes place negligibly with an excursion of 5° of dorsiflexion [Table 2]. Knee and hip also remain in excessive flexion. Constant plantar flexor moment is produced [Figure 4] with continuous absorption of power at the ankle [Figure 7]. At the knee extensor moment is observed [Figure 5] along with early and sustained power generation K2 [Figure 8]. At the hip, extensor moment is observed [Figure 6] along with low (<1 W/Kg) power generation H1 [Figure 9].
The above findings suggest that to prevent the tibia from excessively moving forward, constant plantar flexor moment is produced and plantar flexors continue to act eccentrically. To maintain stability at hip and knee and provide extension, knee and hip extensors work concentrically. However, this power being low is inadequate to provide a complete extension. This is in contrast with the normal gait cycle between10% and 30% ie: the mid-stance period whereby the concentric activity of the gluteus maximus ceases and hip extension is achieved by inertia and gravity. Significant muscle activity at the hip joint takes place here in the frontal plane. In this study, compensations above the hip joint could not be observed as the trunk has not been assessed due to technical limitations.
Between 30% and 60% of the gait cycle [Figure 1], [Figure 2], [Figure 3], it is observed that the ankle, knee, and hip continue to remain in flexion, due to which advancement of the limb over the forefoot, which happens in the normal population, does not happen in this sample.
Furthermore, plantarflexion moment [Table 3] and power generation A2 peak are observed [Figure 7]. At the knee, the extensor moment is seen [Figure 5] with power absorption [Figure 8]. At the hip, the extensor moment is seen along with the continuation of power generation around the hip [Figure 9]. In other words, plantar flexors contract concentrically for push-off and weight transfer. However, this power generated is one-fifth of that of normal push-off power-producing not-so-enough plantarflexion, which further may lead to poor weight transfer. Lin et al. in their study on abnormal kinetic patterns of the knee in gait in spastic diplegia found decreased and practically absent mid-stance trough revealing poor efficiency of weight transmission pattern in vertical ground reaction force. Plantarflexion knee extension couple is incompetent whereby the line of ground reaction force is posterior to the knee. Knee extensors continue to work eccentrically, whereas hip extensors work concentrically to avoid buckling, sustain posture, and provide stability to the superimposed trunk.
Beyond 50% of gait cycle relative extension at the ankle is seen but not beyond 5° [Figure 1], minimal increase in knee flexion [Figure 2] is observed, while hip remains in 10% of flexion [Figure 3]. This may be to achieve the functional objective of weight release and transfer and initiate the task of limb advancement. The stance period ends at right 59% and the left at 65% and the swing phase begins [Table 1].
Excessive hip, knee, and ankle flexion are observed [Figure 3] and [Figure 2] and [Figure 1], respectively] throughout the swing phase. Excursions at all joints were reduced, especially at the knee joint. Hence, preparation for the next stance is incomplete. At the end of the swing, despite abnormal kinematics, the function and task of advancing the limb are achieved.
Electromyographic studies could not be conducted due to technical shortcomings. Trunk parameters have not been assessed due to technical limitations.
| Conclusion|| |
Children with spastic diplegia, GMFCS level 2 presenting with crouch gait, exhibited flexion at all joints in the sagittal plane throughout the gait cycle. To achieve functional stability and prevent collapse, extensor stability in the stance phase was achieved by extensor activity through an extensor group of muscles at all joints throughout the complete gait cycle. Particularly, the knee joint exhibited eccentric activity at all phases of stance providing limb stability. However, reduced joint excursions, poor power generation at all joints, especially at the ankle, and inadequate ankle rockers conveyed poor weight transmission.
Measures to improve excursion at all joints throughout the gait cycle, especially the knee, need to be considered. There is a definite need to improve concentric muscle activity for extensor function at all joints in the stance phase to achieve better extensor stability and weight transmission in this population.
We take this wonderful opportunity to thank Dr. Anil Kumar Gaur, Director- All India Institute of Physical Medicine and Rehabilitation, Mumbai, for giving us this opportunity to conduct this research. We thank Ms. Sandhya Wasnik, Lecturer & HOD(PT), for providing a platform to do this study successfully. We express our deep-felt gratitude to respected Ms. Karen Pavri, Ex-HOD (PT), whose encouragement and support have enlightened us on this subject. We express our deep-felt gratitude to respected Ms. Vimal Telang, Ex-HOD (PT), for her continuous support in this study. Above all, we sincerely thank all the children(patients) who participated in this study, and their parents, without whom this study would have not been possible.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]
[Table 1], [Table 2], [Table 3], [Table 4]