Effects of 8-week selective corrective exercises program on the correction of lumbar lordosis and improving the balance in female karate athletes in Isfahan

Considering the integrity of the skeletal-muscular-neurological system and chain reactions, the optimal neuromuscular efficiency to maintain dynamic stability is established by the proper combination of proper alignment (static/dynamic) and stability strength, any defect in the body, and the useful function can alter the lumbopelvic-hip complex. The mechanical and coupling force of all muscles causes changes in different parts or even the performance of special components, devices, and organs related to the movement system (1,2). The excessive increase of the lumbar arch called the back of the pelvis or lordosis following a change in the position of the pelvis will affect the balance of the human locomotor system and cause numerous disorders in the lumbopelvic-hip complex. The aim of this study was to the effect of corrective exercises of America’s National Academy of Sports Medicine (NASM) on the correction of lumbar lordosis and improving the balance in female karate athletes (3,4).

In this pre-test and post-test semi-experimental study, 40 female karate athletes of Isfahan (age: 18-25 years) participated. Inclusion criteria were consisted of: Female gender, aged between 18-25 years old, BMI between 18-25 kg/m2, affected by Hyperlordosis ≥58° (5), complete the consent form of the subjects for voluntary participation, have not participated in any rehabilitation program in the past six months, absence of pathological complications including a history of fractures, surgery, diseases, and joint disorders in the lumbar-pelvic-thigh area, no lower extremity abnormalities in different views and no mental illness, having at least five years of experience in training and competition In the provincial karate league. Subjects were randomly divided into two groups of experimental and control. All participants signed an informed consent form before starting the study. Ethics approval was taken from the Ethics Committee of the Isfahan University, Isfahan, Iran IR.UI.REC.1397.097, and was carried out according to the Helsinki Protocol. The intervention group received corrective exercises for eight weeks (3 sessions per week/ 45-60 minutes). All subjects were assessed at baseline, and after eight weeks, for lumbar curvature angle and static and dynamic balance performance by a flexible ruler (6,7), stork (8) and Y test (9), respectively. Qualified and trained examiner that assessed hyperlordosis, static, and dynamic balance was blind to the diagnosis and severity of hyperlordosis in a standing posture. Moreover, participants were examined in the habitual, relaxed posture that is usually adopted (10). Individuals were excluded from the study process if they participated in other physical activity and sports that may influence the study results, unwillingness to continue participating in the study, absence of more than three sessions in training, and non-participation in tests. The statistical analysis was performed with statistical software, namely SPSS version 16.0 (SPSS, Chicago, Illinois). All parameter outcomes were evaluated for each participant, and the mean and standard deviation (Mean ± SD) were computed by descriptive statistics test in pre and post-session. The normality of the data and the homogeneity of the groupschr('39') variance were evaluated using Kolmogorov-Smirnov and Leven tests, respectively. Also, data analysis was performed using repeated-measures analysis by SPSS software version 21. The significance level was established at p<0.05.

In the results of within and between group in lumbar lordosis angle, a significant difference was observed in the results of the experimental group (P <0.05). In addition, a significant difference was reported in static and dynamic balance test (p<0.05).

This study aimed to correct lumbar lordosis and improve the static and dynamic balance of female karate athletes with NASM exercises. The results showed a significant improvement in the effect of 8 weeks of NASM training on lumbar lordosis angle (from 63.20 to 43.70 degrees), static balance (from 18.60 to 38.90 second) and dynamic balance (from 1.04 to 1.26 Meter). Overactivity and stiffness of the Psoas muscle, which may be caused by repetitive movements in karate athletes, cause inhibition of the antagonistchr('39')s muscles, including the Glutes Maximus, as well as the stabilizer muscles of the pelvic girdle, including the Multifidus, Deep erector spine, Internal Oblique, and Transversus abdominis, thereby disrupting the extensor mechanism during functional patterns. Because in athletes, due to inhibition of the Glutes Maximus, the Latissimus dorsi muscle may be created as a compensatory mechanism to maintain the upright position of the torso and provide core stabilization and pelvis and throughout the motor chain, to be dominant (hyperactive) (1). The use of myofascial release techniques and static stretching leads to an inhibitory response in the muscle spindle and release the muscles tighten and shorten(1). On the other hand, despite the optimal length-tension relationships, subsequent use of corrective exercises for activation and integration exercises in underactive muscles, increases inter and intramuscular coordination, endurance in strength and optimal force couple relations, and can be desirable arthrokinematics (1,11). To improve the process of neuromuscular efficiency of the human movement system, which is one of the principles of NASM to create and use these techniques as a complete correctional planning system. Furthermore, optimal alignment and functioning of all components (and segments of each component) result in optimum length-tension relationships, force-couple relationships, precise arthrokinematics, and neuromuscular control (1,11,12). Therefore, NASM exercises used in the current study as an effective way to improve lumbar-pelvic-hip complex muscle function and therefore reducing the lumbar lordosis angle can improve the balance of subjects and be used by athletes.