Effects of smartphone screen viewing duration and body position on head and neck posture in elementary school children.

BACKGROUND: Electronic media have become integral parts of modern life, in which prolonged screen viewing time (SVT) by children is nearly unavoidable. Prolonged use of smartphones could lead to musculoskeletal problems. OBJECTIVES: To investigate the effect of SVT on head and neck posture during and after using smartphones for various periods of time in either standing or sitting postures. METHODS: This observational study included 34 male children aged 5-12 years who were assigned to one of two groups based on average smartphone use duration per day: group A comprised 18 children averaging > 4 hours per day (h/day) of smartphone use, and group B comprised 16 children with < 4 h/day of smartphone use. The children's postures were photographed in standing and sitting positions while using a smartphone and 30 min after ceasing smartphone use. The head flexion, neck flexion, gaze, and craniocervical angles were measured using the software program Kinovea. RESULTS: Significant increases were found in head flexion, neck flexion, and gaze angles. Furthermore, both groups saw a significant decrease in craniocervical angle when sitting compared to when standing, both during and 30 min after smartphone use. The head flexion, neck flexion, and gaze angles of group A were significantly higher than those of group B, and the craniocervical angle of group A was significantly lower than that of group B in both postures (p< 0.05). CONCLUSION: SVT is associated with increased neck and head flexion posture in children, especially in a sitting position.

Virtual reality as a pain distractor during physical rehabilitation in pediatric burns.

The purpose of this study was to determine the immediate effect of adding Virtual reality (VR) to conventional burn rehabilitation program on pain and range of motion (ROM) in children with burn injuries during rehabilitation sessions after burn. METHODS: Twenty-two pediatric children (13 boys & 9 girls) with burn injuries and inpatient hospitalization participated in this study. Their age ranged from 9 to 16 years old with 2nd degree deep partial thickness burn of TBSA (10%-25%). They were randomly classified into study and control groups of equal numbers; control group receive passive ROM and stretch exercises, and study group receive the same treatment of the control group in addition to VR training. children in the study group wear the Oculus Rift DK2 as a means for VR and they allowed to choose the favorite video they would like to view before starting the study. The children feel like they are actually in a game. The pain was measured using VAS and the maximum range-of-motion of the joints using electronic digital goniometer before and immediately after the rehabilitation session. RESULTS: There was a significant decrease in pain intensity and increase of ROM after application of VR in the study group and a significant difference between groups after treatment for pain and ROM p < 0.05. CONCLUSION: Based on the current findings adding VR to the rehabilitation program of pediatric burn victims had an immediate effect on decreasing pain and increase ROM.

Ankle and foot mechanics in individuals with chronic ankle instability during shod walking and barefoot walking: A cross-sectional study.

PURPOSE: This study evaluated the angular kinematic and moment of the ankle and foot during shod walking and barefoot walking in individuals with unilateral chronic ankle instability (CAI). METHODS: Recreational soccer players with unilateral CAI were recruited for this cross sectional study conducted between January and August 2019. A total of 40 participants were screened for eligibility but only 31 met the inclusion criteria based on the methods of Delahunt et al and Gribble et al. Except for 3 participants not attending the evaluation session, 28 participants were finally included. A three dimensional motion analysis system made up of ProReflex motion capture unit and an AMTIb Kistler force plate, embedded in the middle of nine meter walkway, were used to assess the ankle and foot angles and moment during shod walking and barefoot walking conditions. A Statistical Package for Social Sciences (version 20.0) was used to analyze data. RESULTS: During shod walking, the ankle joint plantar-flexion range of motion (ROM) at 10% of the gait cycle (GC) and dorsiflexion ROM at 30% of the GC were significantly higher than those during barefoot walking for both feet (p = 0.001, 0.001, 0.027, and 0.036 respectively). The inversion ROM during shod walking was significantly higher than that during barefoot walking for both feet at 10% and 30% of the GC (p = 0.001. 0.001, 0.001, and 0.042 respectively). At 10% of the GC, the eversion moment was significantly higher between barefoot and shod walking for both feet (both p = 0.001). At 30% of the GC, there was no significant difference between shod and barefoot walking plantar-flexion moment of both feet (p = 0.975 and 0.763 respectively), and the eversion moment of both feet (p = 0.116 and 0.101 respectively). CONCLUSION: At the early stance, shod walking increases the ankle plantar-flexion and foot inversion ROM, and decreases the eversion moment for both feet in subjects with unilateral CAI. Therefore, the foot wearing condition should be considered during evaluation of ankle and foot kinematics and kinetics.

Backward walking alters vastus medialis oblique/vastus lateralis muscle activity ratio in females with patellofemoral pain syndrome.

OBJECTIVES: This study aims to examine the effect of backward walking (BW) and forward walking (FW) on the myoelectric activity ratio of the vastus medialis oblique (VMO)/vastus lateralis (VL) in females with patellofemoral pain syndrome (PFPS). PATIENTS AND METHODS: Between September 2016 and December 2016, a total of 40 female participants (mean age 20.9±1.9 years; range, 19 to 26 years) were included in the study. The participants were divided into two groups as those with unilateral PFPS (PFPS group, n=20) and healthy controls (Control group, n=20). Surface electromyography (EMG) from VMO and VL muscles were collected during FW and BW at a speed of 3 km/h using the Myomonitor® IV EMG system. RESULTS: There was a significant increase in the EMG activities of the VMO and VL muscles during BW compared to FW in PFPS and healthy groups (p=0.001). During BW, the VMO activity of PFPS was significantly higher than the healthy controls (p=0.013) without any significant difference in the VL activity (p=0.916). During FW, there was no significant difference in the VMO and VL activities between the groups (p=0.348 and p=0.705), respectively. The VMO/VL ratio of the PFPS group during BW was significantly higher than the FW ratio (p=0.001) without any significant difference between BW and FW of the healthy group (p=0.841). During BW, the ratio of the PFPS group was significantly higher than compared to the healthy controls (p=0.016) without any significant difference between the groups during FW (p=0.100). CONCLUSION: Our study results show that BW increases the VMO muscle activation and preserve the ideal VMO/VL ratio in PFPS patients. Therefore, clinicians should consider BW training when developing rehabilitation programs for females with PFPS.

Isokinetic peak torque and flexibility changes of the hamstring muscles after eccentric training: Trained versus untrained subjects.

OBJECTIVE: The aim of this study was to examine the effect of eccentric isotonic training on hamstring flexibility and eccentric and concentric isokinetic peak torque in trained and untrained subjects. METHODS: Sixty healthy subjects (mean age: 21.66 ± 2.64) were divided into three equal groups, each with 20 voluntary participants. Two experimental groups (untrained and trained groups) participated in a hamstring eccentric isotonic strengthening program (five days/week) for a six-week period and one control group that was not involved in the training program. The passive knee extension range of motion and hamstring eccentric and concentric isokinetic peak torque were measured at angular velocities 60° and 120°/s for all groups before and after the training period. RESULTS: Two-way analysis of variance showed that there was a significant increase in the hamstring flexibility of the untrained and trained groups (25.65 ± 6.32°, 26.55 ± 5.99°, respectively), (p < 0.05) without a significant increase in the control group (31.55 ± 5.84°), (p > 0.05). Moreover, there was a significant increase in eccentric isokinetic peak torque of both the untrained and trained groups (127.25 ± 22.60Nm, 139.65 ± 19.15Nm, 125.40 ± 21.61Nm, 130.90 ± 18.71Nm, respectively), (p < 0.05) without a significant increase in the control group (109.15 ± 20.89Nm, 105.70 ± 21.31Nm, respectively), (p > 0.05) at both angular velocities. On the other hand, there was no significant increase in the concentric isokinetic peak torque of the three groups (92.50 ± 20.50Nm, 79.05 ± 18.95Nm, 92.20 ± 21.96Nm, 79.85 ± 18.97Nm, 100.45 ± 25.78Nm, 83.40 ± 23.73Nm, respectively), (p > 0.05) at both angular velocities. The change scores in the hamstring flexibility (06.25 ± 1.86°) and eccentric peak torque of the untrained group (16.60 ± 4.81Nm, 17.45 ± 5.40Nm, respectively) were significantly higher (p < 0.05) than those of the trained group (03.40 ± 1.14°, 9.90 ± 5.14Nm, 9.80 ± 7.57Nm, respectively), and the control group (00.90 ± 2.10°, 0.60 ± 2.93Nm, 1.40 ± 3.53Nm, respectively), at both angular velocities. Meanwhile, the change scores of the concentric peak torques of the three groups (1.15 ± 1.50Nm, -0.15 ± 2.16Nm, 1.35 ± 1.63Nm, 0.20 ± 2.95Nm, 0.60 ± 2.28Nm, -0.30 ± 2.25Nm) were statistically insignificant (p > 0.05). CONCLUSION: After a six-week period of eccentric isotonic training, the hamstring eccentric peak torque and flexibility of trained and untrained groups improved without changes in the concentric peak torque. Moreover, the improvement of untrained subjects was higher than trained subjects. These findings may be helpful in designing the hamstring rehabilitation program.

Effect of backpack shoulder straps length on cervical posture and upper trapezius pressure pain threshold.

[Purpose] This study was performed to investigate the effect of the length of backpack shoulder straps on upper trapezius muscle pain threshold and craniovertebral angle. [Subjects and Methods] There were 25 participants, with ages from 15 to 23 years old. Upper trapezius pain threshold and craniovertebral angle were measured for all subjects without the backpack then re-measured after walking on a treadmill for 15 min under 2 conditions: 1) wearing a backpack with short straps; and 2) wearing a backpack with long straps. [Results] there was a significant reduction in upper trapezius pain threshold and craniovertebral angle while carrying a backpack with long shoulder straps, compared to use of a backpack with short shoulder straps or no backpack. [Conclusion] A backpack with short straps is less harmful than a backpack with long straps. This result should be considered in ergonomic design of backpacks to reduce the incidence of various physiological and biomechanical disorders.

THE RELATIONSHIP BETWEEN CORE ENDURANCE AND BACK DYSFUNCTION IN COLLEGIATE MALE ATHLETES WITH AND WITHOUT NONSPECIFIC LOW BACK PAIN.

BACKGROUND: Physical activity and sports can be associated with low back pain. However, little is known about the relationship between core stability and nonspecific low back pain (LBP) among athletes. PURPOSE: The purpose of this study was to investigate the relationship between core endurance and back dysfunction in collegiate male athletes with and without nonspecific LBP. METHODS: Fifty-five male collegiate athletes from a variety of sports were recruited for this study. Their mean age was 21.50 ± (2.54) years, mean weight was 70.96 ± (5.33) kg., and mean height was 174.38 ± (4.37) cm. Thirty athletes with non-specific LBP and twenty five healthy athletes were assessed using McGill's anterior, posterior, and left and right plank core endurance tests (seconds) and for dysfunction using the Micheli functional scale (MFS). Pearson's product moment correlations examined the relationships between core endurance and MFS. RESULTS: There were significant differences regarding the measured core endurance tests between the healthy athletes group and the nonspecific LBP group (p < 0.05). Additionally, good negative (r = -0.794) and moderate negative (r = -0.541) correlations were found between MFS and trunk extensor and flexor endurance tests, respectively in the group with nonspecific LBP. CONCLUSION: The results of this study imply that poor core endurance is likely associated with nonspecific LBP in collegiate athletes. Injury risk reduction and back management programs for the athletic population should include strategies that emphasize endurance of the core muscles especially the trunk extensors and flexors. LEVEL OF EVIDENCE: 2b.

Isokinetic imbalance of hip muscles in soccer players with osteitis pubis.

In this study, we compared the isokinetic torques of hip flexors/extensors and abductors/adductors in soccer players suffering from osteitis pubis (OP), with normal soccer players. Twenty soccer male athletes with OP and 20 normal soccer athletes were included in this study. Peak torque/body weight (PT/BW) was recorded from hip flexor/extensor and abductor/adductor muscles during isokinetic concentric contraction modes at angular velocity of 2.1 rad · s(-1), for both groups. The results showed a significant difference between the normal and OP groups for hip flexors (P < 0.05). The normal group had significant, lower PT/BW value than the OP group for their hip flexors (P < 0.05). The hip flexor/extensor PT ratio of OP affected and non-affected limbs was significantly different from that of normal dominant and non-dominant limbs. There were no significant differences between the normal and OP groups for hip extensor, adductor and abductor muscles (P > 0.05). Regarding the hip adductor/abductor PT ratio, there was no significant difference between the normal and OP groups of athletes (P > 0.05). The OP group displayed increase in hip flexor strength that disturbed the hip flexor/extensor torque ratio of OP. Therefore, increasing the hip extensor strength should be part of rehabilitation programmes of patients with OP.