Evaluation of the effects of a novel exercise program in the treatment of low back pain in women working in a seated position: A randomized trial.

BACKGROUND: Low back pain (LBP) in sedentary workers is an increasing problem. Hyperlordosis or hypolordosis of the lumbar spine may be one of the causes of LBP. Various exercise programs are used in the prevention of LBP, but they do not consider individualization for diagnosed hyperlordosis or hypolordosis of the lumbar spine. OBJECTIVE: The purpose of this study was to evaluate the effect of the authors' original exercise program aimed at reducing hyperlordosis or increasing hypolordosis. METHODS: Sixty women aged 26 to 40 working in a sedentary position participated in the study. The sagittal curvature and the range of motion of the lumbar spine flexion were measured with the Saunders inclinometer, and the level of LBP was evaluated using the VAS scale. Subjects were randomly divided into two groups that participated in a 3-month exercise program developed by the authors. The first group performed exercises adjusted to the diagnosed hyperlordosis or hypolordosis, and the second group performed the same exercises regardless of the lumbar lordosis angle. The study was conducted again after completing the exercises. RESULTS: There was a statistically significant difference between the groups (p< 0.0001) in the level of pain, with better results in the group where individualized exercise was used - 60% of the participants reported complete absence of LBP. The lumbar lordosis angle was within normal limits in 97% of the subjects in the first group, and in 47% of the subjects in the second group. CONCLUSION: The results of this study confirm the validity of using individualized exercises with regard to diagnosed hyperlordosis or hypolordosis of the lumbar spine in order to achieve better analgesic and postural correction effects.

Symmetry function - An effective tool for evaluating the gait symmetry of trans-femoral amputees.

BACKGROUND: Prostheses can help persons with trans-femoral amputation (TFA) regain normal function, but such individuals still exhibit gait deviations expressed in gait asymmetries. We apply a specialised tool, the Symmetry Function (SF), to evaluate the symmetry of walking in terms of kinematic and dynamic variables and to identify areas with large side deviations (exceeding defined ±5% threshold) in the movement cycle. RESEARCH QUESTION: Which movements and joints or GRF components revealed the most significant side deviations in the movement cycle? When exactly are they located in the gate cycle? METHODS: In this retrospective observational study, an instrumented motion analysis system was used to register the gait of fourteen patients after unilateral TFA. Measurements involved evaluating the time series of gait variables characterising a range of motion and the ground reaction force components. Comparison of the prosthetic (involved) limb with the sound (uninvolved) limb in TFA patients was carried out on the basis of the Symmetry Function values. RESULTS: The Symmetry Function proved to be an effective tool to localise the regions of asymmetry and limb dominance in the full gait cycle. The difference between sides revealed by the Symmetry Function was the highest for the pelvis and the hip. In the sagittal plane, the pelvis was asymmetrically tilted, reaching the highest SF value of more than 25 % at 60 % cycle time. In the transverse plane, the pelvis was even more asymmetrically positioned throughout the entire gait cycle (50 % difference). The hip in the frontal plane reached a 60 % difference throughout the single support phase for the involved and then for the uninvolved limb. SIGNIFICANCE: The Symmetry Function allows for the detection of gait asymmetries, temporal shifts in the gait phases and may assess the precise in time adaptation of prostheses and rehabilitation monitoring, especially in unilateral impairments.

Symmetry function in gait pattern analysis in patients after unilateral transfemoral amputation using a mechanical or microprocessor prosthetic knee.

BACKGROUND: Above-knee amputations (AKAs) contribute to gait asymmetry. The level of asymmetry is affected by the type of knee prosthetic module. There is limited evidence suggesting that more technically advanced solutions (microprocessor modules; MicPK) are superior to less advanced ones (mechanical modules; MechPK). The study aimed to evaluate the variable range of hip and pelvic joint movements during gait and look for differentiating areas with an increased level of asymmetry of the gait cycle in individuals who underwent an AKA and are equipped with MicPK or MechPK. METHODS: Twenty-eight individuals participated in the study; 14 were assigned to a study group of individuals who underwent a unilateral AKA, and the other 14 were healthy participants as a control group. The movement task was recorded using the optoelectronic SMART-E system following the standard Davis protocol (the Newington model). A new method of quantifying gait symmetry using the symmetry function (SF) is proposed. SF is an integral measure of absolute differences in time-standardized signals between sides throughout the whole cycle of motion variability. RESULTS: In the frontal plane, there were significant differences between groups in the asymmetry of the range of movement in the hip joint of the intact limb. In the middle of the support phase, the intact limb was more adducted in individuals with MicPK and less abducted in people with MechPK (differences in mean 180%, p < 0.000; max 63%, p < 0.000; min 65%, p < 0.000). In the sagittal plane, the range of asymmetry of the flexion and thigh extension of the intact limb was similar to and only slightly different from the physiological gait. In the transverse plane, higher asymmetry values were noted for individuals with MicPK. In the final stage of the swing phase, the thigh was more rotated both externally and internally. The size of the asymmetry, when compared to gait of healthy individuals, reached 50% (differences in mean 115%, p < 0.232; max 62% p < 0.26; min 50, p < 0.154). CONCLUSIONS: In the study group, the assessed ranges of pelvic and thigh movement in the hip joint differed only in the frontal plane. Individuals who underwent a unilateral above-knee amputation may gain less from using MicPK than anticipated.

Asymmetry of lower limb strength and jumping ability of young soccer players.

PURPOSE: The aim of this study was to evaluate the potential correlation between asymmetry of lower limb muscle torque, asymmetry of vertical ground reaction force during take-off in young soccer players and their jumping abilities. METHODS: Twenty-three young soccer player (16.9 ± 0.64 years old) participated in measurements. An isokinetic dynamometer, the Biodex System, was applied to test muscle torque (PT) of the knee flexors and extensors. The vertical ground reaction force (vGRF) was recorded from two Kistler plates. Jumping abilities were assessed with the horizontal (HJ) and vertical jump (VJ) tests. The asymmetry index (AI) was used to assess the asymmetry of the limbs. RESULTS: The asymmetry index showed the highest asymmetry (over 10%) for the PT under static conditions for knee flexors and extensors. The correlation (-0.432, p = 0.038) was found between the asymmetry of vGRF and the height of the VJ. There was no correlation between the muscle torque and the height of the vertical jump. However, a correlation between the HJ length and muscle torque for flexors and extensors of the right and left lower limb was found. CONCLUSIONS: The asymmetry of the muscle torque of the flexors and extensors of the knee joint does not correlate with the results of both jumping ability tests. There was a statistically significant correlation between the vGRF asymmetry index during take-off and the height of the VJ. In the HJ, such a relationship was not found.

A New Method of Evaluating the Symmetry of Movement Used to Assess the Gait of Patients after Unilateral Total Hip Replacement.

PURPOSE: We propose a new concept of symmetry, the symmetry function, as a continuous function of the percentage of differences between sides of body movement and normalised throughout the whole range of motion. The method is used to assess the dynamical symmetry of gait of patients after unilateral total hip replacement (asymmetric group) and healthy people (symmetric group) and also to reveal discrepancies between normal and abnormal movement patterns. METHODS: The gait of twelve male patients (49.7 ± 2.8 y), six weeks after unilateral total hip replacement (uTHR), was analysed against the gait of thirteen healthy men (36.1 ± 3.1 y). The speed of healthy men was matched to the speed of the patients. Comparison of the affected limb in uTHR patients with the healthy limb of able-bodied men was carried out on the basis of the highest symmetry values in the sagittal plane. RESULTS: In uTHR patients, the symmetry function provides information on the symmetry of movements in the whole range of motion in contrast to symmetry indices which are calculated for selected parameters or peak values. Research revealed average asymmetric discrepancies for pelvic tilt up to 250% for the entire gait cycle with a peak of approx. 400% at the end of the loading response and terminal swing phases. Asymmetry of gait observed in other joints was below 200% of the mean range of motion. CONCLUSIONS: Regions of the greatest asymmetry in pathological movements are usually different from the region of the greatest range of motion. Therefore, it is insufficient to measure symmetry only for selected regions during motion. The symmetry function is a simple method which can complement other robust methods in time series data evaluation and interpretation.

Stabilometric profile of handstand technique in male gymnasts.

PURPOSE: This study aimed to determine the characteristic features of handstand posture control associated with a high level of ability among male gymnasts. METHODS: 8 acrobatic gymnasts (4 more and 4 less experienced) participated in the study. They performed a 10-second handstand five times with each hand positioned on one AccuSway (AMTI) force platform and the other hand on the second. Body sway changes were recorded in time series: centre of pressure (COP) and components of the ground reaction force (GRF) (vertical, medial-lateral and anterior-posterior). The COP amplitude and average of GRF components, the index of frequency (by Fast Fourier Transform) for the right and left hand were calculated. RESULTS: More experienced gymnasts performing a handstand concentrate mainly on minimizing anterior-posterior body sway with minimum medial-lateral body sway. Less experienced gymnasts' pressure exerted on a surface by the hands is irregular in a medial-lateral direction. More experienced gymnasts control body position in the handstand and show less variation of body sway compared to less experienced gymnasts. More experienced gymnasts revealed lower frequency of body sway in the handstand compared to less experienced gymnasts. CONCLUSION: The stabilometric profile of more experienced gymnasts means the better posture control in handstand. The minimizing of body sway is compensated by exerting more force on a floor surface and the less experienced athletes cannot do that even after several years of training. The gymnasts of both groups, during standing on their hands, put more load on the right hand.

Muscle Coactivation during Stability Exercises in Rhythmic Gymnastics: A Two-Case Study.

Balance exercises in rhythmic gymnastics are performed on tiptoes, which causes overload of foot joints. This study aimed to evaluate the engagement of muscles stabilizing ankle and knee joints in balance exercises and determine exercises which may lead to ankle and knee joint injuries. It was hypothesized that long-term training has an influence on balance control and efficient use of muscles in their stabilizing function. Two rhythmic gymnasts (8 and 21 years old) performed balances on tiptoes (side split with hand support, ring with hand support) and on a flat foot (back split without hand support exercise). Surface electromyography, ground reaction forces, and kinematic parameters of movement were measured. The measuring systems applied were synchronized with the BTS SMART system. The results show the necessity to limit balance exercises on tiptoes in children because gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) activity significantly exceeds their activity. Ankle joint stabilizing activity of GM and GL muscles in the younger gymnast was more important than in the older one. Performing this exercise, the younger gymnast distributed load on the anterior side of the foot while the older one did so on its posterior. Gymnastics coaches should be advised to exclude ring with hand support exercise from the training of young gymnasts.

Relationship between Asymmetry of Gait and Muscle Torque in Patients after Unilateral Transfemoral Amputation.

Many studies have shown that unilateral transfemoral amputation involves asymmetric gait. Transfemoral amputation leads to muscle atrophy in a tight stump resulting in asymmetry in muscle torque between the amputated and intact limb. This research is aimed at verifying if a relationship between torque values of hip joint flexors and extensors and gait asymmetry in patients with TFA exists. Fourteen adult subjects with unilateral TFA took part in the experiment. Gait symmetry was evaluated based on the ground reaction force (GRF). Measurements of muscle torque of hip flexors and extensors were taken with a Biodex System. All measurements were taken under isokinetic (60°/s and 120°/s) and isometric conditions. The symmetry index of vertical GRF components was from 7.5 to 11.5%, and anterio-posterior GRF from 6.2 to 9.3%. The symmetry index for muscle torque was from 24.3 to 44% for flexors, from 39 to 50.5% for extensors, and from 28.6 to 50% in the flexor/extensor ratio. Gait asymmetry correlated with muscle torque in hip joint extensors. Therapy which enhances muscle torque may be an effective form of patient therapy. The patient needs to undergo evaluation of their muscle strength and have the therapy programme adjusted to their level of muscle torque deficit.

Biomechanical Parameters of Gait after Unilateral Above-knee Amputation. Current State of Research.

The aim of this paper is to present the current state of research on gait parameters in people after unilateral amputation above the knee joint and to compare these gait parameters with those of healthy people. The relevant literature does not include any similar publications. Modern prostheses do not eliminate the asymmetry of gait, although its consequences are diminished. An above-knee amputation leads to significant differences in ground reaction force parameters (GRF) between the sound and amputated limb. The amputated limb is charac-te-rised by lower values of vertical and antero-posterior GRF parameters in comparison with the intact limb. Moreover, during the contact of the heel with the ground, the degree of hip joint flexion of the amputated limb decreases in comparison with the intact limb. Other symptoms of asymmetry between the limbs include asymmetry of pelvic movement in the transverse plane and of the range of movement in the ankle joint. De-creased muscle torque on the hip joint in the amputated limb additionally increases asymmetry of biome-chanical gait parameters after unilateral transfemoral amputation.

The use of electromyography and magnetic resonance imaging to evaluate a core strengthening exercise programme.

BACKGROUND: The question that was asked in the study was whether a training routine based on curl-up exercises with a load provided by body mass of the person increases local muscle strength or local muscle endurance. OBJECTIVE: The aim of this study was to evaluate the effect of 4 weeks training based on a small load and low movement velocity on electrical activity (EMG), cross-sectional area (CSA) of core stabilisers. METHODS: The EMG activity was measured in the rectus abdominis (RA), obliquus abdominis externus and erector spinae (ES) muscles. CSA of the muscles: RA, anterolateral abdominal, psoas major, quadratus lumborum, ES, and multifidus at the level of L3-L4 were measured too. RESULTS: The training increased the CSA and thickness in most of the muscles studied. Statistically significant correlation was found only for the ES circumference (left side) and EMG activity for the right side (r= 0.627, p= 0.022) and left side (r= 0.624, p= 0.023). CONCLUSIONS: The training programme resulted in a increase in the number of curl-up repetitions revealing an endurance increase in abdominal muscles. Furthermore, there was a increase in the EMG activity of the RA. An increase of the CSA of all tested muscles showed an increase of muscle active force.

Foot mechanics in young women are altered after walking in high-heeled shoes.

PURPOSE: Nowadays, fashion has caused that many young women are wearing high-heeled shoes. Therefore, the aim of this study was to examine the effects of long-term walking in high-heeled shoes on the foot mechanics during barefoot gait. METHODS: Forty-three young women (22 ± 2.1 years) divided into two groups participated in this retrospective cohort study. The first group was composed of women who frequently wear high-heeled footwear. The second, infrequent wearers group, consisted of women who preferred flat-heeled shoes. Measurements of gait parameters were recorded for barefoot gait. A motion analysis system and two force plates were used in order to evaluate the lower-limb rocker mechanism, transverse foot arch height and parameters of ground reaction force. RESULTS: Walking in high-heeled shoes modified barefoot foot mechanics, which manifested itself in a shorter duration (by ca. 4%) of the first and second rocker and a significantly longer duration (by 5%) of the third rocker phase as well as a substantial reduction in height of the transverse foot arch (by around 50%) in women habitually walking in high-heeled shoes. A significantly shorter relative duration of the third rocker (44.3% of cycle time) and greater value of the vertical component of ground reaction force (114.7% BW) in the third rocker phase were found in the group of women habitually walking in high-heeled shoes. CONCLUSIONS: The mechanism of foot rolling, with flattened foot arch, and significantly higher values of the vertical component of ground reaction force and shorter time might lead to overload in lowerlimb joints in young women.

Electromechanical response times in the knee muscles in young and old women.

INTRODUCTION: The aim of the study was to compare electromechanical response times [total reaction time (TRT), pre-motor time (PMT), and electromechanical delay] in the knee muscles in groups of young and older women during release of peak torque (PT). METHODS: Fifty women (1 group approximately 20 years of age and the other approximately 60 years of age) participated in the study. PT and electromyographic activity were measured for flexors and extensors of the right and left knee in static conditions in response to a visual stimulus. RESULTS: Significantly longer TRTs (P = 0.05) and PMTs (P = 0.05) were found in the group of older women compared with the younger participants. Asymmetry was found between the older and the younger group of women in PT of knee flexors. DISCUSSION: Significantly longer TRT and PMT phases in the group of older women suggests a longer time for information processing in the central nervous system in older people. Muscle Nerve 56: E147-E153, 2017.

An Investigation into the Relation between the Technique of Movement and Overload in Step Aerobics.

The aim of this research was to determine the features of a step workout technique which may be related to motor system overloading in step aerobics. Subjects participating in the research were instructors (n = 15) and students (n = 15) without any prior experience in step aerobics. Kinematic and kinetic data was collected with the use of the BTS SMART system comprised of 6 calibrated video cameras and two Kistler force plates. The subjects' task was to perform basic steps. The following variables were analyzed: vertical, anteroposterior, and mediolateral ground reaction forces; foot flexion and abduction and adduction angles; knee joint flexion angle; and trunk flexion angle in the sagittal plane. The angle of a foot adduction recorded for the instructors was significantly smaller than that of the students. The knee joint angle while stepping up was significantly higher for the instructors compared to that for the students. Our research confirmed that foot dorsal flexion and adduction performed while stepping up increased load on the ankle joint. Both small and large angles of knee flexion while stepping up and down resulted in knee joint injuries. A small trunk flexion angle in the entire cycle of step workout shut down dorsal muscles, which stopped suppressing the load put on the spine.

Lower extremity power in female soccer athletes: a pre-season and in-season comparison.

PURPOSE: Lower extremity power is an important physical capacity of a soccer athlete. Power represents, and can be modified by, the training of strength and speed. Pre-season and in-season training differs in the relative emphasis on these two quantities. It is nevertheless desirable that the mechanical power remain the same or become higher during the in-season period. The purpose of this study was to identify changes in quantities related to "explosive strength" and to check whether, in collegiate female soccer players, pre- and inseason lower extremity power will remain unaltered. METHODS: Twenty collegiate female soccer players, representing all field positions, participated. Lower extremity power was assessed by a series of drop jumps executed from four different heights (15, 30, 45, and 60 cm). Mechanical power was calculated using subject's mass, jump height, and acceleration due to gravity. This value was further normalized by body mass of each athlete to obtain the relative (or normalized) mechanical power. RESULTS: The normalized lower extremity mechanical power was highest when landing from the 30 cm height for both pre- and inseason periods. However, contrary to expectations, it turned out lower during the in-season than during the pre-season test, even though no significant differences were found between the corresponding jump heights. CONCLUSIONS: It is concluded that altered, perhaps inadequate, training strategies were employed during the in-season period. Besides, advantages of adding the relative mechanical power as a season readiness indicator are underlined compared with relying on the jump height alone.

Symmetry of electromechanical delay, peak torque and rate of force development in knee flexors and extensors in female and male subjects.

PURPOSE: The aim of the study was to evaluate electromechanical delay (EMD), peak torque (PT) and rate of force development (RFD) in selected muscles of right and left lower extremities in groups of female and male subjects. METHODS: The study evaluated 9 volunteer female subjects (mean ± SD: age: 21.67 ± 0.87 years; height: 168 ± 7 cm; body mass: 59.44 ± 4.8 kg) and 10 male university students (mean ± SD: age 22 ± 1.25 years; height: 179 ± 6 cm; body mass: 74.3 ± 5.1 kg) from the Faculty of Physical Education. Muscle torques and electromyographic activity were measured for knee flexors and extensors in static conditions, separately for the right and the left lower extremities. During the measurements, the subjects generated the maximum torque as fast as possible. Surface electrodes were placed on the right and left lower extremities on the following muscles: rectus femoris, vastus lateralis (m.VL), vastus medialis and biceps femoris. RESULTS: Symmetry of EMD, RFD and "flexors-extensors" ratio was found in the muscles of the right and left lower extremities (with an exception of m.VL) in the group of male and female subjects. Statistical analysis demonstrated the presence of asymmetry in PT (297.66 vs. 272.05 N⋅m) and relative force in knee extensors in the group of men (3.90 vs. 3.54 N⋅m⋅kg-1). CONCLUSIONS: Symmetry of EMD and asymmetry of PT might suggest that the cause of asymmetry of the muscular force is mainly morphologi- cal characteristics of the muscle rather than the process of controlling its activity.

Electromechanical delay of abdominal muscles is modified by low back pain prevention exercise.

The objective of the research was to assess the effect of a 4-week-long training program on selected parameters: electromechanical delay (EMD) and amplitude of electromyographic signal (EMG). Fourteen female students of the University School of Physical Education participated in the study. Torques and surface electromyography were evaluated under static conditions. Surface electrodes were glued to both sides of the rectus abdominis (RA), external oblique (EO), and erector spinae (ES) muscles. The 4-week-long program was aimed at strengthening the abdominal muscles and resulted in increased EMD during maximum torque production by flexors of the trunk, increased amplitudes of the signals of the erector spinae ( p = 0.005), and increased EMG amplitude asymmetry of the lower ( p = 0.013) and upper part ( p = 0.006) of the rectus abdominis muscle. In a training program composed of a large number of repetitions of strength exercises, in which the training person uses their own weight as the load (like in exercises such as curl-ups), the process of recruitment of motor units is similar to that found during fatiguing exercises and plyometric training.

Assessment of gait after bilateral hip replacement. Case study.

Total hip arthroplasty (THA) is one of the most effective methods of treatment of severe hip osteoarthritis (HOA). In many cases pathological gait patterns persist despite properly conducted surgery and disturb the normal wear of the artificial joint surfaces. The aim of the study was to conduct functional and biomechanical assessment of gait in a patient after bilateral THA due to severe degenerative changes in the hip. The assessment focused on the gait parameters which significantly deviate from a normal gait pattern at various stages of treatment. Physiotherapeutic assessment of the patient included measurements of the range of motion in lower limb joints, the Timed Up and Go test, and pain assessment. Biomechanical assessment involved measurements of spatiotemporal gait parameters and the dynamic range of motion using BTS Smart-E motion analysis system. Although clinical examinations after both the first and second procedure suggested recovery of the patient's physical function, biomechanical assessment of her gait after the second procedure indicated the presence of deviations from a normal gait pattern. Secondary to a limited range of internal/external hip rotation, extension, and abduction, corresponding indices were still in the pathological range.

Assessment of strength & velocity parameters of hip joint muscles in rehabilitation of a patient with lower limb amelia. Case study.

We studied a 19-year-old patient with congenital partial absence of certain left lower limb structures (amelia) with no additional developmental defects. The patient had no fibula or foot bones and the tibia was reduced to 3 cm, which made it impossible to use a crural prosthesis. The aim of the study was to assess the strength capacity of muscles influencing the ipsi- and contralateral hip joint in the amelic patient. Compared to healthy individuals, patients with a congenital absence of lower limb demonstrate a marked disproportion in muscle peak torque between hip flexors and hip extensors, which may lead to damage to the weaker muscle group. The disproportions may be reduced with a rehabilitation programme aimed to strengthen the hip joint extensors.

Symmetry of support scull and vertical position stability in synchronized swimming.

Maintaining the body underwater in the so-called vertical position, where the body is inverted (head down) and balanced, is made possible by performing the support scull movement by the upper limbs. In synchronized swimming, the main criteria for judging this vertical position are maintaining body stability and the maximum height of the lower limbs one is able to extend out of the water. Therefore, it seems important to examine for any correlations between the symmetry of the upper limb's movement (sculling) and the ability to maintain balance of the body. The aim of this study was to use a dynamical asymmetry index (DAI) to assess the symmetry of the upper limb movements performed in synchronized swimming. The use of the dynamical asymmetry index is considered to be advantageous over the asymmetry coefficient, which is better known in literature on the subject and has been used by numerous authors, as it not only evaluates the magnitude of the asymmetry, but also indicates in which phases of movement asymmetry is the greatest or where it is the least significant.

Relative power of the lower limbs in drop jump.

The purpose of this paper was to determine the power produced by the lower limbs in the take-off phase in drop jumps (DJ) and the correlation between the power and load measured by dropping height after take-off. The research group (N = 17) contained students practicing football, volleyball, basketball, athletics, high jump, swimming and fencing. The individual characteristics 'power-load' of the players and the observation of the changes during the training process enable the coaches to choose precise loads and at the same time to improve the training. The criterion of choosing loads in the plyometric training may be relative power output of lower limbs referred to the DJ height. While the condition allowing player to perform this type of training may depend on obtaining greater power in drop jump than in counter movement jump.