Oliver Ludwig

Changes in Habitual and Active Sagittal Posture in Children and Adolescents with and without Visual Input – Implications for Diagnostic Analysis of Posture

INTRODUCTION Poor posture in children and adolescents has a prevalence of 22-65% and is suggested to be responsible for back pain. To assess posture, photometric imaging of sagittal posture is widely used, but usually only habitual posture positions (resting position with minimal muscle activity) are analysed. AIM The objective of this study was 1) to investigate possible changes in posture-describing parameters in the sagittal plane, when the subjects changed from a habitual passive posture to an actively corrected posture, and 2) to investigate the changes in posture parameters when an actively corrected posture was to be maintained with closed eyes. MATERIALS AND METHODS In a group of 216 male children and adolescents (average 12.4 ± 2.5 years, range 7.0 - 17.6 years), six sagittal posture parameters (body tilt BT, trunk incline TI, posture index PI, horizontal distances between ear, shoulder and hip and the perpendicular to the ankle joint) were determined by means of photometric imaging in an habitual passive posture position, in an actively erect posture with eyes open, and in active stance with eyes closed. The change in these parameters during the transition between the posture positions was analysed statistically (dependent t-Test or Wilcoxon-Test) after Bonferroni correction (p<0.004). RESULTS When moving from a habitual passive to an active posture BT, TI, PI, dEar, dShoulder, and dHip decreased significantly(p< 0.004). When the eyes were closed, only the perpendicular distances (dEar, dShoulder, and dHip) increased significantly. The parameters that describe the alignment of the trunk sections in relation to each other (BT, TI, PI), remained unchanged in both actively regulated posture positions. CONCLUSION Changes in sagittal posture parameters that occur when a habitual passive posture switches into an active posture or when an active posture is to be maintained while the eyes are closed can be used for diagnostic purposes regarding poor posture and posture regulation.

Age-dependency of posture parameters in children and adolescents

[Purpose] Poor posture in children and adolescents is a well-known problem. Therefore, early detection of incorrect posture is important. Photometric posture analysis is a cost-efficient and easy method, but needs reliable reference values. As children’s posture changes as they grow, the assessment needs to be age-specific. This study aimed to investigate the development of both one-dimensional posture parameter (body inclination angle) and complex parameter (posture index) in different age groups (childhood to adolescence). [Subjects and Methods] The participants were 372 symptom-free children and adolescents (140 girls and 232 boys aged 6–17). Images of their habitual posture were obtained in the sagittal plane. High-contrast marker points and marker spheres were placed on anatomical landmarks. Based on the marker points, the body inclination angle (INC) and posture index (PI) were calculated using the Corpus concepts software. [Results] The INC angle significantly increased with age. The PI did not change significantly among the age groups. No significant differences between the corresponding age groups were found for PI and INC for both sexes. [Conclusion] When evaluating posture using the body inclination angle, the age of the subject needs to be considered. Posture assessment with an age-independent parameter may be more suitable.

Change of Muscle Activity as Well as Kinematic and Kinetic Parameters during Headers after Core Muscle Fatigue

In soccer, headers are a tactical measure and influenced by numerous factors. The goal of this study was to identify whether changes in kinematics and muscular activity, especially of the head-stabilizing muscles, occur during headers when the core musculature is fatigued. In two subgroups, muscular activity (12 amateur players, age 23.6 ± 4.2 years) and kinematics and dynamics (29 amateur players, age 23.7 ± 2.8 years) were examined during straight headers on a pendulum header. Data were collected before and after the core muscles were fatigued by an exercise program. Telemetric surface EMG, 3D acceleration sensor, force plate, and video recordings were used. Under fatigue, the activity of M. erector spinae and M. rectus abdominis was significantly reduced in the preparation phase of the header. The activity of M. sternocleidomastoideus was significantly increased during the jump phase, and the hip extension angle during maximum arched body tension was significantly reduced under fatigue. Jumping height, acceleration force impulse, and linear head acceleration were also significantly reduced. We conclude that fatigue of the core muscles affects the motion technique of the header and the activity of the muscle groups stabilizing the head. Therefore, the necessity of specific training in soccer should be emphasized from a medical-preventive point of view.

Intra-individual gait pattern variability in specific situations: implications for forensic gait analysis

In this study, inter- and intra-individual gait pattern differences are examined in various gait situations by means of phase diagrams of the extremity angles (cyclograms). 8 test subjects walked along a walking distance of 6m under different conditions three times each: barefoot, wearing sneakers, wearing combat boots, after muscular fatigue, and wearing a full-face motorcycle helmet restricting vision. The joint angles of foot, knee, and hip were recorded in the sagittal plane. The coupling of movements was represented by time-adjusted cyclograms, and the inter- and intra-individual differences were captured by calculating the similarity between different gait patterns. Gait pattern variability was often greater between the defined test situations than between the individual test subjects. The results have been interpreted considering neurophysiological regulation mechanisms. Footwear, masking, and fatigue were interpreted as disturbance parameters, each being a cause for gait pattern variability and complicating the inference of identity of persons in video recordings.

Differences in the Dominant and Non-Dominant Knee Valgus Angle in Junior Elite and Amateur Soccer Players after Unilateral Landing

More than 70% of all knee injuries in soccer occur in non-contact situations. It is known that increased lower limb dynamic knee valgus is associated with such situations. Little has been found out about differences in knee kinematics of the dominant (kicking) and non-dominant (supporting) leg during a single leg landing. A total of 114 male adolescent soccer players (age 14.6 ± 1.1 years) from elite (N = 66) and amateur soccer clubs (N = 48) performed a single leg drop landing down from a box. For each leg, the two-dimensional dynamic knee valgus angle (DKVA) was calculated. Paired t-tests were used to statistically determine significant differences between dominant and non-dominant leg DKVA, and t-tests were calculated between the two performance groups. Statistically significant differences (p < 0.05) were identified for the DKVA between the dominant and non-dominant leg for both amateur and elite players, showing a greater DKVA for the dominant leg. Group differences for the DKVA between amateur and elite players were not found, neither for the dominant, nor for the non-dominant leg. It can be concluded that the non-dominant leg showed more stable dynamics than the dominant leg during unilateral landing regardless of the player’s performance level. This could be due to adaptions to sport-specific requirements. Therefore, it is recommended that programs to prevent knee injuries among soccer players consider the dynamics of each leg individually.

Interrelationship between postural balance and body posture in children and adolescents

[Purpose] This study examined possible interrelationships between postural sway and posture parameters in children and adolescents with a particular focus on posture weakness. [Subjects and Methods] 308 healthy children and adolescents (124 girls, 184 boys, aged 12.3 ± 2.5 years) participated in the study. Posture parameters (posture index, head protrusion, trunk inclination) were determined based on posture photos in the sagittal plane. Postural sway was measured during 20 seconds on a force plate. The Pearson’s product-moment correlation coefficients between the anthropometric and posture parameters and the sway path length (SPL) were calculated, as well as the coefficient of determination R2. [Results] There is a weak but significant correlation between age or body mass index of the test subjects and the SPL. There is no statistically significant correlation between posture parameters and the SPL. Children and adolescents with posture weakness do not exhibit a changed SPL. [Conclusion] Therefore, therapy of poor posture must be considered separately from therapeutic measures for the improvement of balance skills.

The Influence of Fatigued Core Muscles on Head Acceleration during Headers in Soccer

The core muscles play a central role in stabilizing the head during headers in soccer. The objective of this study was to examine the influence of a fatigued core musculature on the acceleration of the head during jump headers and run headers. Acceleration of the head was measured in a pre-post-design in 68 soccer players (age: 21.5 ± 3.8 years, height: 180.0 ± 13.9 cm, weight: 76.9 ± 8.1 kg). Data were recorded by means of a telemetric 3D acceleration sensor and with a pendulum header. The treatment encompassed two exercises each for the ventral, lateral, and dorsal muscle chains. The acceleration of the head between pre- and post-test was reduced by 0.3 G (p = 0.011) in jump headers and by 0.2 G (p = 0.067) in run headers. An additional analysis of all pretests showed an increased acceleration in run headers when compared to stand headers (p < 0.001) and jump headers (p < 0.001). No differences were found in the sub-group comparisons: semi-professional vs. recreational players, offensive vs. defensive players. Based on the results, we conclude that the acceleration of the head after fatiguing the core muscles does not increase, which stands in contrast to postulated expectations. More tests with accelerated soccer balls are required for a conclusive statement.

Groin Pain and Muscular Imbalance of Quadriceps and Hamstrings in an Elite Soccer Player – A Case Study

Soccer and football players are exposed to a high risk of groin pain. In some cases, the pubic symphysis is the origin of the problems.This article presents a case report of a young elite soccer player who, over a period of two years, suffered from pain in the groin and symphysis area. The right leg was the kicking leg. Imaging techniques did not reveal pathological findings. Sports hernia, osteomyelitis, enthesopathy, adductor tendonitis, and muscle sprains, as well as rheumatic or urogenital disorders were excluded.A 3 D posture analysis was performed to examine the statics of the body and pelvis. The maximum isometric strength of the left and right leg adductors and abductors, as well as the knee flexors and extensors were measured.We found a muscular imbalance resulting from the type of sport the athlete engaged in with an unfavourable ratio between the right knee extensor and flexor muscles. Comparing sides, an imbalance was also identified between the right and left knee extensor. This imbalance resulted in a one-sided forward tilt of the right hemi-pelvis. This pelvic torsion may lead to an increase in shear forces in the pubic symphysis, which we suspected to be the reason for the recurring problems.After three months of specific training exercises, the pelvic position was harmonised and the muscular imbalances were significantly reduced. Even 6 months after completion of the specific training exercises, the player remained without complaints despite his unvaried soccer training intensity.Causal treatment of functional pain in the groin or symphysis area should take into account the ipsilateral and contralateral strength ratios of the knee extensors and flexors as well as the three-dimensional position of the pelvis.

Therapy of poor posture in adolescents: Sensorimotor training increases the effectiveness of strength training to reduce increased anterior pelvic tilt

Abstract Background: Increased anterior pelvic tilt is one important contributor to poor posture in children and adolescents and caused by muscular imbalance. This study aims at identifying the extent to which a sensorimotor training reduces anterior pelvic tilt more effectively than pure strength and stretch training alone. Methods: 54 male adolescents (age 13–17) with an increased pelvic tilt angle >14° were matched to three groups (strength training STR, strength + sensorimotor training STR + SENS, control CON). Maximum isometric torques for knee flexion (HA), trunk flexion (RA), and trunk extension, and pelvic tilt were measured before and after a 12 week physical therapy schedule. Two-way mixed ANOVA were calculated. Results: For STR and STR + SENS the relative torque of HA and RA increased significantly (p < 0.05) between pre- and post-test. Significant improvement of the pelvic tilt angle was identified in both training groups, with STR + SENS exhibiting a significantly larger degree of improvement. Conclusions: Sensorimotor exercises improve the effectiveness of physical fitness training to reduce anterior pelvic tilt and should therefore supplement existing therapeutic programs.

SENSORI-MOTOR INSOLES MAY INCREASE PERONEUS LONGUS ACTIVITY DURING STANCE PHASE OF HUMAN GAIT

Background Sensori-motor insoles are supposed to influence muscle activity of the ankle stabilizing muscles during stance phase of human gait by imposing pressure upon tendon structures. For this purpose, specially shaped elements are integrated in the insoles. In particular, activation of m. peroneus longus as a main pronator of the foot is supposed to prevent ankle sprains. Nevertheless, no evidence for a potential effect of sensori-motor insoles could be shown until now. The objective of this study was to examine changes in muscle activity of the peroneus longus (PL) and tibialis anterior (TA) muscle caused by sensori-motor insoles with a lateral wedge. Methods For 32 healthy subjects the activity of the peroneus longus and tibialis anterior muscle was recorded by means of surface EMG (Noraxon Telemyo). A randomized, double blinded cross-over-design was used. Subjects walked in several sub-tests both in neutral shoes with sensori-motor insoles and with dummy insoles. Sensori-motor insoles (Shore 35, Springer AG, Berlin) had a convex-formed spot that was placed above the skin of the peroneus longus tendon, 8 mm distal to the inferior retinaculum. Pressure sensors under the heel and forefoot were used to identify gait phases. In a former study changes in muscular activity peaks of the peroneus longus muscle could be found mainly in the period between 14% and 34% stance phase.1 Therefore, integrated EMG was calculated for both PL and TA for the periods of 0–15% (loading response), 15–50% (mid stance) and 50–100% (terminal stance). Sub-tests with sensori-motor insoles and dummy insoles were compared for each subject by statistical means (paired t-test). Effect size and post hoc power were calculated using G*Power 3.1. Results PL activity in mid stance was statistically significant higher (p=.0083, post hoc power =.98) with sensori-motor insoles (18.4±12.17 uV*s) compared to dummy-insoles (10.0±7.6 uV*s). Effect size (Cohens d) was .80, indicating a large effect. For other gait phases and for TA activity no significant effects (p<.05) could be found. Discussion As changes in peroneus activity could be found only in mid stance when both the body weight is transferred to the foot and the sensori-motor spots impose pressure on the skin we conclude that increased muscular activation is due to increased afferent input. In both initial contact and terminal stance the sensori-motor spots do not influence afferent input and motor activation pattern of peroneus longus. As the ankle joint is sensitive to disturbances (supination) during mid stance an increased activity of pronator muscles might help to stabilize the foot and possibly help to prevent ankle sprains.