Single Leg Support Time Research Articles

Gait and sEMG characteristics of lower limbs in children with unilateral spastic cerebral palsy during walking

BackgroundChildren with unilateral spastic cerebral palsy (USCP) have muscle hypertonia, balance, and coordination defects that affect gross motor skills, especially walking. Understanding the gait characteristics and lower limb muscle activation patterns of USCP children can provide an objective and quantitative basis for patient assessment and treatment plan formulation. ObjectiveThis study compared the gait and lower limb muscle activation characteristics of children with USCP and with typical development (TD) during walking. MethodsWe recorded gait and sEMG data of 20 children with USCP, and 20 with typical development. sEMG signals were acquired from the bilateral tibialis anterior (TA) and lateral gastrocnemius muscles (LG) during walking. The root mean square (RMS) value, integrated electromyographic (iEMG) value and co-contraction ratio (CR) were used to evaluate muscle activity. Student's t Test and non-parametric rank sum Test were used to compare the differences between the data groups (significance level of 0.05). ResultsThe stance time, step length, speed, single leg support time ratio, ground impact, pre-swing angle, and muscle strength of the affected side were significantly decreased compared to those of the unaffected side in children with USCP (P < 0.05), while the swing phase, muscle tonus of LG were significantly prolonged (P < 0.05). Compared with TD children, children with USCP exhibited reduced bilateral walking ability, particularly noticeable in their smaller pre-swing angle(P < 0.05), diminished muscle strength of the TA and LG, as well as LG spasms(P < 0.05). SignificanceChildren with USCP have decreased ambulatory gait stability. Step length, pull acceleration, pre-swing angle, and CR can be used as sensitive indicators for gait assessment. Strengthening the TA muscle and reducing ankle spasm may help improve gait and postural stability in children with USCP.

Association Between Temporal Asymmetry and Muscle Synergy During Walking With Rhythmic Auditory Cueing in Survivors of Stroke Living With Impairments

ObjectiveTo examine the relationship between temporal asymmetry and complexity of muscle synergy during walking using rhythmic auditory cueing (RAC) and the factors related to changes in muscle synergy during walking with RAC in survivors of stroke. DesignCross-sectional study. SettingWards at 2 medical corporation hospitals. ParticipantsForty survivors of stroke (N=40; mean age, 70.4±10.3 years; time since stroke, 72.2±32.3 days) who could walk without physical assistance. InterventionsNot applicable. Main Outcome MeasuresThe participants were assessed in a random block design under 2 conditions: comfortable walking speed (CWS) and walking with RAC. Single-leg support time, kinematics, and electromyograms were measured. Factors related to the complexity of muscle synergy (variance accounted for by 1 synergy [VAF1]) between the walking conditions were examined using hierarchical multiple regression analysis. ResultsIn the RAC condition, lower limb flexion and knee flexion angles, single-leg support time on the paretic side, and the symmetry index of single-leg support time were increased compared with those in the CWS condition. VAF1 was decreased in the RAC condition (73.9±0.15) compared with that in the CWS condition (76.9±0.13, P=.002). Hierarchical multiple regression analysis revealed that the change in VAF1 was explained by change in single-leg support time (R2=0.43, P=.002). ConclusionsThe RAC condition demonstrated a more complex representation of muscle synergy than the CWS condition; the change in single-leg support time on the paretic side related to the changes in muscle synergy more than changes in lower limb angle. These findings can help in the walking-training concept to improve muscle synergy deficits in survivors of stroke.

Quantitative gait analysis after total hip arthroplasty through a minimally invasive direct anterior approach: A case control study

IntroductionTotal Hip Arthroplasty (THA) leads to excellent clinical and functional results. The Minimally Invasive Anterior Approach (MIAA) theoretically allows rapid recovery and a reduction in the need for rehabilitation, but alterations in muscle and static balance have previously been demonstrated. Kinetic, kinematic and muscular alterations have been shown to persist up to 1year postoperatively but data beyond 1year postoperatively is lacking. Thus, the objective of this study was to compare the data from Quantitative Gait Analysis (QGA) coupled with electromyography (EMG), of patients one year postoperatively with THA through MIAA, compared to an asymptomatic control group. HypothesisWe hypothesized that QGA and EMG parameters would not normalize beyond one year postoperatively. Patients and MethodsTwenty-seven patients were recruited, including 15 subjects (64.6±6.6years) operated on by MIAA, who at 15.9±3.1months postoperatively, along with 12 asymptomatic control subjects (68.9±9.7years), who underwent QGA and maximal isometric muscle strength tests, coupled with EMG on the gluteus medius and maximus, Tensor Fascia Lata (TFL) and Sartorius muscles. The spatiotemporal parameters of walking (step length, walking speed, cadence, single leg support time), kinetics (vertical ground reaction forces, hip moments in the 3 planes) and kinematics (coxofemoral and pelvic amplitudes) were analyzed. ResultsThe walking speed was lower on the non-operated side of the experimental subjects (0.96ms−1 compared to 1.13ms−1 for asymptomatic [p=0.018]), as was the step length on the operated side (0.53m compared to 0.60m for asymptomatic [p=0.042]). Maximal isometric muscle strength was lower in subjects operated on for the gluteus maximus and medius (p=0.004), compared to asymptomatic subjects. Moments were lower in the subjects operated on in extension (0.72Nm on the operated side, 0.75Nm on the non-operated side compared to 1.06Nm for asymptomatic [p=0.007 and p=0.024]) and lateral rotation (0.09Nm on the operated side, 0.05Nm on the non-operated side compared to 0.16Nm for asymptomatic subjects [p=0.009 and p=0.0005]). Hip adduction amplitudes were lower on the operated side compared to asymptomatic subjects (3.93° versus 9.14° for asymptomatic [p=0.005]). Pelvic amplitudes in the frontal plane were lower amongst operated subjects (0.44° against 1.97° for asymptomatic [p=0.041]). Pelvic amplitudes in the sagittal plane were higher in the operated subjects (15.74° on the operated side, 15.43° on the non-operated side compared to 9.65° for asymptomatic [p=0.041 and p=0.032]). DiscussionOur initial hypothesis was validated, since walking deficits persisted beyond one year postoperatively after THA through MIAA. A decrease in maximal isometric muscle strength of the gluteus medius and gluteus maximus was observed, as well as an alteration of kinetic and kinematic parameters in the sagittal and frontal planes. The results were in agreement with the literature and reflected the establishment of compensatory mechanisms to overcome alterations in joint strength and range more than one year postoperatively. These results would allow rehabilitation programs to be more specific and would justify a study on the other approaches for THA. Level of evidenceIII; non-randomized control trial.

Biomechanical analysis of gait patterns in children with intellectual disabilities

Children with intellectual disabilities (ID) typically master walking skills much later than typically developing (TD) children and have poor postural control ability. This study aimed to explore the gait ability and characteristics of children with ID and whether there is any difference in walking ability between them and TD children. In this study, integrating kinematic-biomechanic-dynamic measurement methods and corresponding analysis methods (video analysis, three-dimensional force analysis and electromyography test analysis) were used to characterise and compare the gait patterns between ID children and TD children. ID children's step length/leg length ratio was lower than TD children. The left-leg single-leg support time and step length of ID children were shorter than TD children. While walking, ID children touched the ground with the whole foot pad and could not powerfully thrust against the ground with their toes. Their left legs had obvious disadvantages compared with their right legs. ID children's lower limb muscle strength was lower than TD children, and their thigh muscles had an obvious compensation function. Correcting ID children's gait should be an important teaching goal for physical education institutors and teachers. Muscle-strength and flexibility training can help ID children reinforce core strength and better coordinate lower limbs.

Motor Impairment and Its Influence in Gait Velocity and Asymmetry in Community Ambulating Hemiplegic Individuals

ObjectivesTo determine the most important motor impairments that are predictors of gait velocity and spatiotemporal symmetrical ratio in patients with stroke. DesignCross-sectional, descriptive analysis study. SettingHuman performance laboratory of the University of Santo Tomas. ParticipantsIndividuals with chronic stroke (N=55; 34 men, 21 women) who are community dwellers. InterventionsNot applicable. Main Outcome MeasuresThe gait velocity and spatiotemporal symmetrical ratio (step length; step, stance, swing, single-leg support, and double-leg support stance times) was determined using Vicon motion capture. We also calculated motor impairment of the leg and foot using Brunnstrom’s stages of motor recovery, evaluated muscle strength using the scoring system described by Collin and Wade, and assessed spasticity using by the modified Ashworth Scale. ResultsRegression analysis showed that plantarflexor strength is a predictor of gait velocity and all temporospatial symmetry ratio. Knee flexor and extensor strength are predictors in single-leg support time and double-leg support time symmetry ratio, respectively. On the other hand, hip adductor and quadriceps spasticity are predictors of swing time and step length symmetry ratio. ConclusionDifferent motor impairments are predictors of stroke gait abnormality. Interventions should be focused on these motor impairments to allow for optimal gait rehabilitation results.

Relationship between walking ability of patients with stroke and effect of body weight-supported treadmill training.

[Purpose] Reports on the amount of unloading maximizing walking ability in patients with stroke are limited. The effect of body weight-supported treadmill training (BWSTT) in patients with stroke has not been clarified. We aimed to investigate the effects of unloading rate during BWSTT on the gait of patients with stroke and the relationship between BWSTT and walking ability on flat ground. [Participants and Methods] We performed BWSTT in 17 patients at three unloading rates: 0%, 20%, and 40%. Then, we examined the walking speed and rate, number of steps, single-leg support time ratio, and root mean square before and after unloading. Furthermore, we examined the relationship between walking ability on flat ground and immediate effects of BWSTT at each unloading rate. [Results] We observed no significant improvement under all conditions. However, walking ability improved at unloading rates of 20% and 40%, with poor temporal symmetry while walking on flat ground. [Conclusion] Our results revealed that BWSTT has diverse effects depending on the unloading rate and the ability to walk on flat ground. In particular, it tends to be highly effective for those who have poor sway and symmetry, which may serve as an index for prescribing BWSTT.

Improving spatiotemporal gait parameters in spastic diplegic children using treadmill gait training

BackgroundEven though several physiotherapy techniques help to improve the spatiotemporal gait parameters of diplegic children, the efficacy of treadmill gait training together with conventional treatment techniques on spatiotemporal parameter improvement needs more investigation. ObjectiveThis study's main purpose is to investigate the effect of treadmill gait training as an adjunct to conventional physiotherapy treatment on the spatiotemporal gait parameters of diplegic children. MethodsTwenty diplegic children were distributed randomly into two equal groups (a control group of ten children who received a traditional treatment and an experimental group of ten children who received the traditional treatment together with treadmill gait training). Gait data were collected using a Vicon three-dimensional motion analysis system during regular walking. ResultsWalking speed, cadence, step length, stride length, and single limb support were enhanced in both groups (p < 0.05). Cadence and walking speed increased by 6.5 steps/min and 0.2 m/sec respectively in the experimental group, compared to the control group. Also, step length, stride length and single limb support time increased by 0.13 m, 0.27 m, and 0.07 s respectively in the experimental group, compared to the control group. ConclusionThe use of treadmill gait training together with conventional physical therapy treatment enhances the walking performance of diplegic children by improving several spatiotemporal gait parameters. Furthermore, walking balance is improved by increasing the single-leg support time.

Effect of Horizontal Whole-Body Vibration Training on Trunk and Lower-Extremity Muscle Tone and Activation, Balance, and Gait in a Child with Cerebral Palsy

Patient: Male, 10Final Diagnosis: Cerebral palsySymptoms: Movement disorderMedication: —Clinical Procedure: —Specialty: RehabilitationObjective:Unusual or unexpected effect of treatmentBackground:The aim of the present study was to investigate the effect of horizontal whole-body vibration (WBV) training on trunk and lower-extremity muscle tone and activation, balance, and gait in a child with spastic diplegia cerebral palsy.Case Report:A 10-year-old male with spastic diplegia cerebral palsy received horizontal WBV training followed by conventional physiotherapy (50 min per day, 12 days per month), but only conventional physiotherapy during follow-up. Muscle tone was assessed using the Modified Ashworth Scale (MAS) and muscle activation with surface electromyography. Balance was assessed using the Timed Up and Go test (TUG) and Pediatric Balance Scale (PBS), and gait parameters were assessed using the GAITRite system. Assessment was performed at 3 points: pre-intervention, post-intervention, and follow-up. Following the intervention, MAS decreased in both the hip extensor and right ankle plantar flexor. Muscle activation increased post-intervention in the bilateral erector spinae (ES), rectus abdominis (RA), rectus femoris (RF), and right tibialis anterior (TA) during standing, and in the left RA, bilateral RF, gastrocnemius (GCM), and left TA during squatting. At follow-up, activation increased in the right ES, left RA, and RF during standing. At post-intervention and follow-up, improvement was observed in PBS score, gait velocity, right step length, and right stride length, with decreased single-leg support time, and double support and toe deviation angle.Conclusions:Horizontal WBV training can safely and effectively maintain and improve physical performance and can be considered for inclusion in rehabilitation programs.

Combined Visual Feedback with Pelvic Assistance Force Improves Step Length during treadmill walking in Individuals with Post-Stroke Hemiparesis.

Altered spatiotemporal gait characteristics are common impairments after stroke. Visual feedback has been used to improve spatiotemporal gait characteristics. In addition, pelvic assistance force applied in the mediolateral direction to the paretic side can improve walking pattern. Potentially, combined visual feedback and pelvic assistance force can have better rehabilitation outcomes on walking patterns. The purpose of this study was compare the effects of combined visual feedback with pelvic assistance force and visual feedback only during treadmill walking in individuals with post-stroke hemiparesis. Fifteen subjects with hemiparesis due to chronic (>6 months) stroke participated. A computer monitor placed in front of the treadmill was used to provide visual feedback on subjects' weight bearing on the paretic leg. A customized cabledriven robotic system was used to apply pelvic assistance force. The magnitude of pelvic assistance force was 9% of body weight. The session consisted of 5 sections: 1-min baseline, 7-min treadmill training (visual feedback only or combined visual feedback and pelvic assistance force), 1-min post-training (no visual feedback or pelvic assistance force), 1-min standing break, and 5-min treadmill training. The order of the visual feedback only and combined visual feedback and pelvic assistance force sessions was randomized across subjects. Spatiotemporal gait variables within the session, including stance time, single leg support time and step length, were computed. Combined visual feedback with pelvic assistance force resulted in a better improvement in step length of the paretic leg when compared to visual feedback only (p=0.03). Walking patterns after stroke could potentially be improved by applying visual feedback regrading paretic leg weight bearing and pelvic assistance force. Future study is needed to confirm the effectiveness of visual feedback for treadmill training after stroke.

Assessing gait changes in firefighters after firefighting activities and while carrying asymmetric loads

One of the most common causes of injuries among firefighters is slips, trips, and falls on the fireground. Acute fatigue from firefighting activities and/or carrying asymmetric loads might impact gait characteristics increasing slip, trip, and fall risk. The purpose of this study was to examine the effects of fatigue from simulated firefighting activities and carrying asymmetric loads (fire hose over one shoulder) on firefighters’ gait behavior. Both firefighting activities and asymmetric hoseload carriage led to shorter step lengths, stride lengths, single leg support time, and longer double leg support time, suggesting firefighters adopted cautious gait strategies. Simulated firefighting activities performed in either a live-fire training tower or laboratory-based environmental chamber using a firefighting activity simulator resulted in nearly identical effects on gait kinematics. This result suggests that gait assessment in a laboratory-based environmental chamber can be used as effective simulations in place of specialized burn facilities.

Dose-Associated Changes in Gait Parameters in Response to Exercise Programs after Total Knee Arthroplasty: Secondary Analysis of Two Randomized Studies.

BackgroundRehabilitation plays an important role to improve the outcomes of total knee arthroplasty (TKA). Evidence about the appropriate dose of exercise to recover gait dysfunction after TKA is limited. We posed the research question: In patients during the post-acute stage after TKA, is increased dose of exercise associated with larger improvements in gait parameters such as step length and single support time?MethodsThis was a secondary analysis from two randomized studies on exercise after TKA to investigate dose-dependence of gait parameters in response to exercise. Participants were 50 years or older who underwent unilateral TKA at least two months prior. They participated in 2 months of supervised exercises followed by 4 months of a home exercise program. The primary outcome was change in gait parameters from baseline to 6 months. Participants were divided in three groups according to the dose of exercise: group 1 (light-to-moderate intensity exercise), group 2 (high intensity + functional exercise), and group 3 (high intensity + functional + balance exercise). Jonckheere-Terpstra test was used to test if the magnitude of changes in gait parameters increased from group 1 to group 3 in an ordered fashion.ResultsIncreased dose of exercise was associated with progressive increases in step length in the operated-limb (p=0.008) and decreases in step length in the non-operated limb (p=0.011). Increased dose of exercise was associated with ordinal decreases in loading response time (p=0.049) and increases in single-leg support time (p=0.021) on the operated- limb, but not on the non-operated-limb. Increased dose of exercise was associated with decreases in unloading time on the non-operated-limb (p=0.011) but not on the operated-limb (p=0.400).ConclusionsSignificant dose-response of exercise on gait parameters support the promotion of more intensive exercise programs that combine functional and balance training programs after TKA.

The influence of dual-task conditions on movement in young adults with and without Down syndrome

This investigation compared spatial and temporal movement parameters of a sample of young adults with Down syndrome (DS) (N=12) and individuals without disabilities (IWD) (N=12) under dual-task conditions. Subjects performed a walking task at a preferred speed in isolation and again while holding a plate and cup, carrying tray and cups, talking on a phone, or buttoning a shirt. Spatial and temporal values were compared using a 2 (group) × 5 (conditions) repeated measures analysis of variance. Analysis of spatial components separately indicated that step length, step width, stride length and stride width revealed significant group and condition interactions (p ≤.01). Temporal components yielded significance in velocity and single-leg support time (p ≤.01). The current results support the notion that along with impairments to qualitative motor skills, individuals with DS are also impaired in higher order executive functioning (EF), as measured by a dual-task paradigm. It was concluded that movements are less efficient and functional in individuals with DS when an additional task is encountered while walking. We theorized that the motor program was sufficient for general locomotion but was not sufficiently developed to allow individuals with DS to modify or alter their movements to changing cognitive conditions that increasingly taxed EF. As gait and balance are trainable in this population, we recommend developing appropriate exercise and motor skill interventions during childhood and adolescents to increase strength, stability, and more "robust" ambulatory motor schema.

Gender differences in decreased ambulation and balance associated with Alzheimer's Disease

This is a preliminary report on the effects of Alzheimer's Disease (AD) on motor function, a less‐studied effect of this debilitating disease. We analyzed gait characteristics using the Gaitrite system (n=10 F, n=7 M) and balance using the BioSway (n=4 F, n=4 M) along with a standard timed Get‐Up‐And‐Go (GG) test (n=10 F, n=9 M). All participants (aged 81.2±6.6 years) were clinically diagnosed with AD. Our results reveal that men performed significantly better than women in the GG (14.71±8.74 s vs. 32.15±18.33 s respectively, p&lt;0.02). There were no gender differences in stride length (left leg vs. right leg p=0.06 and p=0.07 respectively) and single leg support time (left vs. right leg p=0.74 and p=0.55 respectively). Further, there were no gender differences in medial/lateral (p=0.76) or anterior/posterior balance (p=0.96). Our results indicate that men and women exhibit similar declines in ambulatory performance with AD. We are investigating whether gender differences may be attributable to muscle mass, prior levels of activity, and progressive stage of the disease.This work was supported through Willamette University iHSI and Atkinson grants to JH and SS.

New Foot Pressure Activated Sensory Compensation System for Posture-Control Enhancement in Amputees

A computerized foot pressure activated sensory compensation system using subsensory electrical stimulation combined with visual-auditory biofeedback was developed. The proposed system was used for enhancing standing balance and gait performance for amputees. In this pilot study, we hypothesized that the static balance with single limb support and gait performance during treadmill walking could be improved by providing proprioceptive neuromuscular facilitation using subsensory stimulation and visual-auditory biofeedback in amputee, respectively. To test this hypothesis, five unilateral transtibial amputees who consecutively wore prosthetics over two years were recruited. Experimental results show a reduction in all of the postural sway indexes and increase in single-leg support time index during single-leg quiet standing by applying subsensory stimulation. With visual-auditory biofeedback for providing clue for heel contact and toe push-off condition during treadmill ambulation, an improvement in all four dynamic gait performance indexes in amputees was verified. These findings suggest that the proposed system with subsensory electrical stimulation and visual-auditory biofeedback mechanisms may be effective in compensating sensory loss and improving posture control for amputees.

Static Standing Trunk Sway Assessment in Amputees – Effects of Sub-Threshold Stimulation

Sub-threshold electrical stimulation can enhance the sensitivity of the human somatosensory system to improve the balance control capability of elderly was shown in recent rehabilitation articles. The purpose of this study was to evaluate the postural sway of trans-tibial amputees when performing single leg quiet standing on firm surface. Four unilateral trans-tibial amputees who consecutively wore prosthetics over 2 years were recruited in this study. Subjects performed single leg quiet standing trails with sub-threshold electrical stimulation applied at the quadriceps muscle during the trails. Spatial co-ordinates for the determination kinematic data (sway distance) of the center of mass (COM) on second sacral (S2) were collected using an ultrasound-based Zebris CMS-HS system. The single leg quiet standing test is measure considered to assess postural steadiness in a static position by a spatial measurement. The common notion is that a better postural steadiness, i.e. less postural sway, allows for longer time single leg quiet standing. However, there is lack of evidence how postural steadiness during single leg quiet standing changes over time. In this article, we hypothesized that the static balance of single leg quiet standing could be improved for providing proprioceptive neuromuscular facilitation using sub-sensory stimulation in amputees. To test this hypothesis, a computerized sub-threshold low-level electrical stimulation device was developed and proposed for clinical study. Experimental results show that reduction in all of the postural sway indices (constant time sway length, max sway distance and average sway distance) and increase in single leg support time index during single leg quiet standing by applying sub-sensory stimulation. The single leg quiet standing test findings suggest that sub-threshold electrical stimulation rehabilitation strategies may be effective in improving static balance performance for amputees.

Static Standing Trunk Sway Assessment in Amputees – Effects of Sub‐Threshold Stimulation

Sub‐threshold electrical stimulation can enhance the sensitivity of the human somatosensory system to improve the balance control capability of elderly was shown in recent rehabilitation articles. The purpose of this study was to evaluate the postural sway of trans‐tibial amputees when performing single leg quiet standing on firm surface. Four unilateral trans‐tibial amputees who consecutively wore prosthetics over 2 years were recruited in this study. Subjects performed single leg quiet standing trails with sub‐threshold electrical stimulation applied at the quadriceps muscle during the trails. Spatial co‐ordinates for the determination kinematic data (sway distance) of the center of mass (COM) on second sacral (S2) were collected using an ultrasound‐based Zebris CMS‐HS system. The single leg quiet standing test is measure considered to assess postural steadiness in a static position by a spatial measurement. The common notion is that a better postural steadiness, i.e. less postural sway, allows for longer time single leg quiet standing. However, there is lack of evidence how postural steadiness during single leg quiet standing changes over time. In this article, we hypothesized that the static balance of single leg quiet standing could be improved for providing proprioceptive neuromuscular facilitation using sub‐sensory stimulation in amputees. To test this hypothesis, a computerized sub‐threshold low‐level electrical stimulation device was developed and proposed for clinical study. Experimental results show that reduction in all of the postural sway indices (constant time sway length, max sway distance and average sway distance) and increase in single leg support time index during single leg quiet standing by applying sub‐sensory stimulation. The single leg quiet standing test findings suggest that sub‐threshold electrical stimulation rehabilitation strategies may be effective in improving static balance performance for amputees.

WALKING PATTERN ANALYSIS OF PRIMARY SCHOOL CHILDREN DURING LOAD CARRIAGES ON TREADMILL 492

The effect of carrying school bags on children was investigated so as to supply a picture of recommended weight of school bag and prevent vertebral problems. Two dimensional video filming and heart rate measurement were carried out in 10 male students of Primary Six (average 11.6 years) during walking on a treadmill with backpack of 0%, 10%, 15%, and 20% of body weight respectively. The body height and weight of the subjects were 149.95 ± 5.55 cm and 44.45 ± 11.41 kg respectively. The subjects were requested to walk at a speed of 1.1m/s for 15 minutes on a treadmill, at each condition of carrying. Loads were put inside the backpack placed on the mid back of the subject. 0% body weight was used as a control for carrying. Video tapes were then digitized and analyzed on Peak Motion Measurement System. Results showed no statistically significant difference between different load conditions in stride length, stride rate, double leg support time, swing time and center of gravity height as well as in heart rate. It was found there was significant difference in single leg support time among different load condition. The F-ratio was F(3.36)=3.461, P<0.05. One-way Scheffe Test indicated that there was significant difference in single leg support time only at between 0% and 20% body weight load conditions. Significant difference was found in inclination of trunk between 0% and the other three load conditions. The F-ratio was F(3.36)=11.64, p<0.01, showing there were significant differences in inclination of trunk between 0% and the other three load conditions. The study could not provide any support to the recommendation of 10% body weight as the guideline for carrying school bag among children. It was also found that heart rate could not be used as the only physiological testing parameter of carrying school bag on children. It was suggested that longitudinal study and the study with EMG testing should be carried out in order to provide information on the causes of vertebral problems related to the load of school bags.