Lower Extremity Muscle Tendon Interaction Around Knee During Gait Among Adolescent Children with Cerebral Palsy with Varying Crouch Angle.

Background: Optimal management and surgical planning of severe bony deformities and muscle tendon unit contractures demands comprehensive evaluation of all structures including the dynamic muscle tendon length of all muscles around the joint during gait. Objectives: Present study aimed to explore dynamic muscle-tendon length for all muscles around the knee joint along with pelvis, hip, and ankle joint kinematics among adolescent children with varying crouch angle. Methods: Muscle-tendon length of 29 adolescent children with cerebral palsy with varying crouch angles was computed using a full-body musculo-skeletal model and expressed as a percentage of muscle-tendon length during walking compared to resting condition. Results: Children with knee flexion angle greater than 25° demonstrated lower anterior pelvic tilt and 11% greater muscle-tendon length of semimembranosus and biceps femoris during stance phase of gait compared to children with knee flexion angle less than 25° and typically developing children (p < 0.01). Conclusions: The findings of present study reported that routine bedside clinical evaluation in adolescent children with knee flexion angle greater than 25° revealed moderate shortening of hamstring muscle in supine position. Whereas instrumented objective evaluation of gait demonstrated lengthened hamstring muscle and reduced hip extension and relatively lower anterior pelvic tilt. Therefore, it may be valuable to add objective assessment of dynamic muscle-tendon length to kinematics of all lower-extremity joint motion during gait, in order to understand the muscle-joint interactions; particularly in children with severe crouch and plan specific, tailor-made surgical and non-surgical interventions.

Crouch Gait in Cerebral Palsy: Current Concepts Review.

Background and Objective: Crouch gait is the most common pathological gait pattern in cerebral palsy and is commonly seen in patients with spastic diplegia. It is characterized by excessive knee flexion throughout the stance phase of gait cycle. The aim of this review is to discuss the current literature about CG for a more comprehensive understanding. Methods: A literature review about various aspects of crouch gait in cerebral palsy was undertaken. This included its etiology and pathophysiology, biomechanics in crouch gait, natural history of untreated crouch gait, clinical and radiological evaluation and different modalities of available treatment. Results: The etiology is multifactorial and the pathophysiology is poorly understood. This makes its management challenging, thereby leading to a variety of available treatment modalities. Inadvertent lengthening of muscle-tendon units is an important cause and can be avoided. A meticulous clinical and radiological evaluation of patients, supplemented by observational and instrumented gait analysis is mandatory in choosing correct treatment modality and improving the treatment outcome. Younger children can be managed satisfactorily by various non-operative methods and spasticity reduction measures. However, crouch gait in cerebral palsy has a progressive natural history and surgical interventions are needed frequently. The current literature supports combination of various soft tissue and bony procedures as a part of single event multilevel surgery. Growth modulation in the form of anterior distal femur hemiepiphysiodesis for correction of fixed flexion deformity of knee has shown encouraging results and can be an alternative in younger children with sufficient growth remaining. Conclusions: In spite of extensive research in this field, the current understanding about crouch gait has many knowledge gaps. Further studies about the etiopathogenesis and biomechanics of crouch using instrumented gait analysis are suggested. Similarly, future research should focus on the long term outcomes of different treatment modalities through comparative trials.

Influence of Crouch Angle on Postural Stability in Quiet Stance and Functional Tasks Among Children with Cerebral Palsy.

The aim of this study is to investigate postural stability and function (functional tasks) in younger (<12 yr) and older (>12 yr) children with lesser (<25°) and greater crouch (>25°) during stance. Postural stability and functional tasks were assessed in 53 ambulatory children with spastic cerebral palsy (CP). Younger and older children with greater crouch angle demonstrated higher displacement of center of pressure compared to children with lesser crouch angle during gait (p < .01). All (younger and older) children with severe crouch angle demonstrated strong association of postural control with stair climb (r = 0.732; p < .05) and timed-up-and-go test (r = 0.84; p < .01). Greater crouch angle demonstrates a moderate association with postural stability (r = 0.528; p < .01) in quiet stance and a strong association with functional tasks in children with CP (r = 0.7-0.84; p < .05).

Gross motor function profile of children with cerebral palsy in a low-resource setting: A call for reflection on the model of care.

PURPOSE: The current study aimed to explore Gross Motor Function Measure (GMFM) profiles among children with cerebral palsy (CP) at various Gross Motor Function Classification System (GMFCS) levels in a low-resource setting. METHODS: Ambulatory capacity of children with CP was classified using GMFCS levels. Functional ability of all participants was measured using GMFM-88. Seventy-one ambulatory children with CP (61% males), were studied after signed informed consent was obtained from parents and assent from children older than 12 years. RESULTS: Children with CP in a low-resource setting had 12-44% lower GMFM scores in dimensions of standing, walking, running, and jumping with reference to children from high-resource settings with similar ambulatory capacity reported previously. The most affected components across various GMFCS levels were 'sitting on a large and small bench from floor,' 'arm-free squatting,' 'half-kneeling,' 'kneel-walking,' and 'single-limb hop'. CONCLUSION: Knowledge of GMFM profiles can guide clinicians and policymakers in low-resource settings for strategic rehabilitation planning and extend the focus of rehabilitation from restoration of body structure and function to the wider domain of social participation in leisure, sport, work, and the community at large. Additionally, providing tailored rehabilitation based on a profile of motor function can ensure an economically, environmentally, and socially sustainable future.

Validation of wearable inertial sensor-based gait analysis system for measurement of spatiotemporal parameters and lower extremity joint kinematics in sagittal plane.

Wearable inertial sensor-based motion analysis systems are promising alternatives to standard camera-based motion capture systems for the measurement of gait parameters and joint kinematics. These wearable sensors, unlike camera-based gold standard systems, find usefulness in outdoor natural environment along with confined indoor laboratory-based environment due to miniature size and wireless data transmission. This study reports validation of our developed (i-Sens) wearable motion analysis system against standard motion capture system. Gait analysis was performed at self-selected speed on non-disabled volunteers in indoor (n = 15) and outdoor (n = 8) environments. Two i-Sens units were placed at the level of knee and hip along with passive markers (for indoor study only) for simultaneous 3D motion capture using a motion capture system. Mean absolute percentage error (MAPE) was computed for spatiotemporal parameters from the i-Sens system versus the motion capture system as a true reference. Mean and standard deviation of kinematic data for a gait cycle were plotted for both systems against normative data. Joint kinematics data were analyzed to compute the root mean squared error (RMSE) and Pearson's correlation coefficient. Kinematic plots indicate a high degree of accuracy of the i-Sens system with the reference system. Excellent positive correlation was observed between the two systems in terms of hip and knee joint angles (Indoor: hip 3.98° ± 1.03°, knee 6.48° ± 1.91°, Outdoor: hip 3.94° ± 0.78°, knee 5.82° ± 0.99°) with low RMSE. Reliability characteristics (defined using standard statistical thresholds of MAPE) of stride length, cadence, walking speed in both outdoor and indoor environment were well within the "Good" category. The i-Sens system has emerged as a potentially cost-effective, valid, accurate, and reliable alternative to expensive, standard motion capture systems for gait analysis. Further clinical trials using the i-Sens system are warranted on participants across different age groups.

Lower extremity joint loading during Bounce rope skip in comparison to run and walk.

BACKGROUND: Bounce rope-skip holds immense scope as an aerobic exercise in space and time constrained urban setting with additional constraints placed by pandemic situations such as Covid 19, wherein adherence to commonly performed weight-bearing, aerobic activities like walking and running is a challenge. Limited knowledge informing biomechanical demands and misconceptions about knee joint loading, confines safe application of bounce rope-skip in health promotion. Thus, present study aimed to explore kinematics and lower-extremity joint loading during rope-skipping compared to walking and running. METHODS: Following ethical approval, 3D motion analysis of bounce rope-skip, walk and run was captured from 22 healthy female participants aged 18-25yr using 12-camera Vicon system and 2AMTI force plates. Three trials for bounce rope-skip were recorded with five skip-jumps on force-plates at a cadence of 105 skips/min. Mid-skip, mid-gait and mid-run data were averaged to compute kinetic and kinematic variables for hip, knee and ankle during loading/initial contact, take-off/push-off and flight/mid-swing phases of rope-skip, walk and run. RESULT: Average time of one rope-skip cycle was 1.2sec; mean foot contact time was 0.55sec and flight time was 0.65sec. In one bounce rope-skip cycle, hip motion ranged between 13.4o-35.3oflexion; knee between 13.6 o-67.9° flexion and ankle between 34.5odorsiflexion to-13.40plantarflexion. Vertical ground reaction force (vGRF) during rope-skip (landing-phase) was lower compared to run; however, it was higher than walk (p < 0.001). In coronal plane, peak hip and knee adductor moment during rope-skip were lower compared to run and higher than walk (p < 0.001). CONCLUSION: Bounce rope-skip generated low lower extremity joint loading compared to run; supporting its prescription as a hip and knee joint-protective aerobic weight-bearing exercise for health promotion in young adults.

Exploration of Muscle Activity Using Surface Electromyography While Performing Surya Namaskar.

BACKGROUND: Limited information is available to understand the muscular demands of composite yogasanas such as Surya Namaskar, which is essential to guide prescription of Surya Namaskar in management of commonly prevalent musculoskeletal disorders such as back and knee pain. AIM: Therefore, muscle activation pattern in prime accessible muscles of the trunk and lower extremity, namely lower trapezius, latissimus dorsi, erector spinae, rectus abdominis, gluteus maximus, vastus lateralis, and gastrocnemius, was explored during the traditional 12-pose sequence of Surya Namaskar. METHODOLOGY: Muscle activity of 8 healthy trained yoga practitioners (5 females and 3 males) was recorded using wireless, eight-channel surface electromyography (sEMG) system at a sampling rate of 2000 Hz and bandwidth of 20-450 Hz. Data were processed using EMGworks analysis software, and root mean square values were normalized against muscle activity during maximal voluntary contraction (MVC). RESULTS: The 12-pose sequence of Surya Namaskar activated muscles of the trunk, upper and lower extremities to a varying extent, in each pose. During sustenance, erector spinae demonstrated the highest muscle activation in Hastapadasana (64.7% MVC in Pose 3and 64.3% MVC in Pose 11), lower trapezius during Hastapadasana (41.9% MVC in Pose 3and 39.2% in Pose 11); latissimus dorsi during Bhujangasana (37.4% MVC), Ashtangasana (34.9% MVC), and Parvatasana (34.6% MVC in Pose 8,); gluteus maximus in Ashwa Sanchalanasana (38.5% MVC in Poses 9 and 4); and vastus lateralis in Ashwa Sanchalanasana (34.9% MVC). Rectus abdominis demonstrated low activation throughout Surya Namaskar, presenting the highest activation during Parvatasana (22.8% MVC). All recorded muscles demonstrated greater activation during transition compared to sustenance of pose. CONCLUSION: Surya Namaskar elicited high-to-moderate muscle activation of major postural muscles of the trunk and lower extremity during alternating flexion-extension movements of the spine, supporting its prescription in prevention and management of mechanical low back pain among vulnerable groups of people.

Kinematics of Suryanamaskar Using Three-Dimensional Motion Capture.

BACKGROUND: Suryanamaskar, a composite yogasana consisting of a sequence of 12-consecutive poses, producing a balance between flexion and extension is known to have positive health benefits for obesity and physical fitness management, upper limb muscle endurance, and body flexibility. However, limited information is available on biomechanical demands of Suryanamaskar, i.e., kinematic and kinetic. AIMS: The present study aimed to explore the kinematics of spine, upper, and lower extremity during Suryanamaskar to enhance greater understanding of Suryanamaskar required for safe and precise prescription in the management of musculoskeletal disorders. METHODS: Three-dimensional motion capture of Suryanamaskar was performed on 10 healthy trained yoga practitioners with 12-camera Vicon System (Oxford Metrics Group, UK) at a sampling frequency of 100 Hz using 39 retro-reflective markers. Data were processed using plug-in-gait model. Analog data were filtered at 10Hz. Joint angles of the spine, upper, and lower extremities during 12-subsequent poses were computed within Vicon Nexus. RESULTS: Joint motion was largely symmetrical in all poses except pose 4 and 9. The spine moved through a range of 58° flexion to 44° extension. In the lower quadrant, hip moved from 134° flexion to 15° extension, knee flexed to a maximum of 140°, and 3° hyperextension. Ankle moved in a closed kinematic chain through 40° dorsiflexion to 10° plantarflexion. In the upper quadrant, maximum neck extension was76°, shoulder moved through the overhead extension of 183°-56° flexion, elbow through 22°-116° flexion, and wrist from 85° to 3° wrist extension. CONCLUSIONS: Alternating wide range of transition between flexion and extension during Suryanamaskar holds potential to increase the mobility of almost all body joints, with stretch on anterior and posterior soft tissues and challenge postural balance mechanisms through a varying base of support.