Effectiveness of muscle energy technique in patients with nonspecific low back pain: a systematic review with meta-analysis.

INTRODUCTION: Low back pain (LBP) is a major cause of physical disability in the world. The origin of this condition can be due to differents causes, with a specific cause or of unknown mechanical origin,being characterized as unspecific. In this case a physical therapy treatment approach with manual therapy is relevant, which includes the muscle energy technique (MET) classified as a common conservative treatment for pathologies of the spine, mainly in LBP and disability. This study assessed the effectiveness of the muscle energy technique on nonspecific low back pain. EVIDENCE ACQUISITION: Patients with acute, subacute or chronic non-specific low back pain. The primary outcomes were pain and disability. This study was designed by a systematic review and meta-analysis, registered in PROSPERO (CRD42020219295). For the report and methodological definitions of this study, the recommendations of the PRISMA protocol and the Cochrane collaboration, were followed, respectively. EVIDENCE SYNTHESIS: The search yielded 164 citations, which 19 were eligible randomised trials were included in the review (N.=609 patients with low back pain). The methodological quality of the studies averaged 4.2 points, with an interval of 2 to 7 points. Three RCTs showed satisfactory methodological quality (PEDro Score ≥6). For patients with chronic LBP, a significant result on pain (but with a small and clinically unimportant effect) in favor of MET versus other (MD=-0.51 [95% CI,-0.93 to -0.09] P=0.02, N.=376, studies=11, I2=80%). In patients with subacute LBP, MET enabled a significant and moderate effect to reduce pain intensity when compared to the control group (MD=-1.32 [95% CI,-2.57 to -0.06] P=0.04, N.=120, studies=3, I2=88%). No significant effects were observed for the disability. CONCLUSIONS: MET is not considered an efficient treatment to improve the incapacity of the lumbar spine, but it may be beneficial in reducing the intensity of LBP, although showing a small clinical effect in chronic LBP and a moderate effect in subacute LBP.

The "Journal of Functional Morphology and Kinesiology" Journal Club Series: PhysioMechanics of Human Locomotion.

We are glad to introduce the Third Journal Club of Volume five, the third issue. This edition is focused on relevant studies published in the last years in the field of PhysioMechanics of Human Locomotion, chosen by our Editorial Board members and their colleagues. We hope to stimulate your curiosity in this field and to share with you the passion for the Sports Medicine and Movement Sciences seen also from the scientific point of view. The Editorial Board members wish you an inspiring lecture.

The "Journal of Functional Morphology and Kinesiology" Journal Club Series: Utility and Advantages of the Eccentric Training through the Isoinertial System.

We are glad to introduce the first Journal Club of volume five, the first issue. This edition is focused on relevant studies published in the last years in the field of eccentric training, chosen by our editorial board members and their colleagues. We hope to stimulate your curiosity in this field and to share with you the passion for the sport, seen also from a scientific point of view. The editorial board members wish you an inspiring lecture.

Session-RPE for quantifying load of different youth taekwondo training sessions.

BACKGROUND: The session rating of perceived exertion (session-RPE) proved to be a valuable method to quantify the internal training load (ITL) in taekwondo. However, no study validated this method in youth taekwondo athletes performing different training sessions. Thus this study aimed at evaluating the reliability of the session-RPE to monitor the ITL of prepubescent taekwondo athletes during pre-competitive (PC) and competitive (C) training sessions. METHODS: Five female (age: 12.0±0.7 y; height: 1.54±0.08 m; body mass: 48.8±7.3 kg) and four male (age: 12.0±0.8 yrs; height: 1.55±0.07 m; body mass: 47.3±5.3 kg) taekwondo athletes were monitored during 100 individual sessions (PC: N.=33; C: N.=67). The Edwards' HR method was used as reference measure of ITL; the CR-10 RPE scale was administered at 1- and 30-minutes from the end of each session. RESULTS: No difference for gender emerged. The ITLs of C (Edwards: 228±40 arbitrary units, AU) resulted higher than that of PC (192±26 AU; P=0.04). Although all training typologies and data collections achieved significant correlations between Edwards' and session-RPE methods, a large relationship (r =0.71, P<0.001) emerged only for PC sessions evaluated at 30 minutes of the recovery phases. CONCLUSIONS: Findings support coaches of prepubescent taekwondo athletes to successfully use session-RPE to monitor the ITL of different training typologies. However, PC training evaluated at 30 minutes of the recovery phase represents the best condition for a highly reliable ITL perception.

Influence of HMB supplementation and resistance training on cytokine responses to resistance exercise.

PURPOSE: The purpose of this study was to determine the effects of a multinutritional supplement including amino acids, ß-hydroxy-ß-methylbutyrate (HMB), and carbohydrates on cytokine responses to resistance exercise and training. METHODS: Seventeen healthy, college-aged men were randomly assigned to a Muscle Armor™ (MA; Abbott Nutrition, Columbus, OH) or placebo supplement group and 12 weeks of resistance training. An acute resistance exercise protocol was administered at 0, 6, and 12 weeks of training. Venous blood samples at pre-, immediately post-, and 30-minutes postexercise were analyzed via bead multiplex immunoassay for 17 cytokines. RESULTS: After 12 weeks of training, the MA group exhibited decreased interferon-gamma (IFN-γ) and interleukin (IL)-10. IL-1ß differed by group at various times. Granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, IL-7, IL-8, IL-12p70, IL-13, IL-17, monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-1 beta (MIP-1ß) changed over the 12-week training period but did not differ by group. CONCLUSIONS: Twelve weeks of resistance training alters the cytokine response to acute resistance exercise, and supplementation with HMB and amino acids appears to further augment this result.

Physiological versus psychological evaluation in taekwondo elite athletes.

PURPOSE: To anticipate outstanding athletic outcomes, the selection process of elite athletes simultaneously considers psychophysiological and technical parameters. This study aimed to investigate whether selected and nonselected athletes for the Italian national taekwondo team could be discriminated by means of sport specific performances and psychophysiological responses to training. PARTICIPANTS: 5 established Italian national athletes and 20 elite Italian taekwondo black belt athletes (9 women, 16 men; age 23.0 ± 3.1 y; body mass 67.0 ± 12.1 kg). METHODS: To update the Italian national-team roster, the 20 elite athletes participated in a 1-wk selection camp (7 training sessions). Selected athletes (n = 10) joined established national athletes during the following 3-wk national training period (7 training sessions/wk). During the 1-wk selection camp, differences (P < .05) between selected and nonselected athletes in performances, heart-rate responses, blood lactate accumulation [La], subjective ratings of perceived exertion (session RPE), and mood were examined. During the 3-wk national training period, differences (P < .05) in mood between selected and established national athletes were investigated. RESULTS: With respect to nonselected athletes, selected athletes responded better to training in terms of session RPE (P = .047) and [La] (P = .046). No difference in performance and mood between subgroups emerged. After the 3-wk national training period, differences (P = .035) emerged for confusion, with decreases in the established national athletes and increases for recently selected athletes. CONCLUSIONS: Session RPE and [La] seem to be more effective than psychological measures in discriminating between elite taekwondo athletes. Evaluation of mood could be effective in monitoring athletes' response to national training.

Technical and tactical analysis of youth taekwondo performance.

This study aimed to analyze the technical and tactical aspects of young athletes during official taekwondo competitions. Fifty-nine youth taekwondo athletes (43 boys and 16 girls; age range: 10-12 years; weight category range: <24 to >59 kg) with at least 2 years of taekwondo training consisting of three 90-minute training sessions for 3 d·wk⁻¹ participated in this study. Thirty-seven matches (three 1-minute rounds, with 1-minute rest in between) were analyzed to verify the differences (p ≤ 0.05) in offensive and defensive actions in relation to gender (male, female), match outcome (winners, nonwinners), kicking leg (front, rear), and round (first, second, third). No difference emerged for gender and match outcome. With respect to defensive actions (8.4 ± 12.0%), youth athletes engaged more frequently (p < 0.0001) in offensive actions (91.6 ± 12.0%), which showed a significant decrease (p < 0.016) from the first round (42.3 ± 21.8%) to the second (33.1 ± 14.8%) and third (24.5 ± 16.0%) ones. Kicks performed with the rear leg (94.4 ± 7.8%) occurred more frequently (p < 0.0001) than those performed with the front leg (5.6 ± 7.8%). In considering that a high level of coordination is required to perform front-leg kicks and defensive actions necessitate a high level of tactical skills, these findings might indicate a not-yet complete attainment of fundamental coordinative capabilities in 10- to 12-year-old athletes, independently of match outcome. To enhance coordination capabilities in youth athletes, coaches are recommended to structure their training including skill-ability and sport-ability drills.

Salivary cortisol and alpha-amylase reactivity to taekwondo competition in children.

The aim of this study was to evaluate the effects of an official taekwondo competition (three 1-min rounds with a 1-min recovery in-between) on heart rate (HR), salivary alpha-amylase (sAA), and salivary-free cortisol (sC) in children. Parental consent was obtained for 12 young (10.4 ± 0.2 years) male taekwondo athletes. Saliva sample were collected 15 min before and 1 min after an official taekwondo competition, and at 30, 60, and 90 min of the recovery period. To evaluate the exercise intensity during the competition, HR was measured and expressed as a percentage of individuals HR(peak). Athletes spent 78% of the time working at HR > 90% HR(max), with significant increases from round 1 to round 2 and 3. Peak sAA observed at the end of the match (169.6 ± 47.0 U/mL) was different (P = 0.0001) from the other samplings (pre-competition 55.0 ± 14.0 U/mL, 30-min recovery 80.4 ± 17.7 U/mL, 60-min recovery 50.5 ± 7.6 U/ml; 90-min recovery 53.2 ± 9.6 U/mL). Peak sC values observed at 30-min recovery (17.9 ± 3.5 nmol/L) were different (P < 0.0001) from pre-competition (5.6 ± 0.9 nmol/L), post-competition (9.0 ± 2.0 nmol/L), 60-min recovery (10.3 ± 2.6 nmol/L) and 90-min recovery (4.2 ± 0.8 nmol/L) values. These findings confirm that taekwondo competitions pose a high stress on young athletes. The different sAA and sC reactions in response to the physical stressor mirror the faster reactivity of the sympathetic-adrenomedullary system relatively to the hypothalamic-pituitary-adrenocortical system, respectively. This experimental paradigm might represent a useful model for further research on the effects of various stressors (i.e., training and competition) in taekwondo athletes.

Effects of official Taekwondo competitions on all-out performances of elite athletes.

This study investigated physiological and performance aspects of 15 (4 women and 11 men) elite Taekwondo athletes (24.0 ± 5.7 years) during their National Championship. The load of the competition was evaluated by means of heart rate (HR) and blood lactate (La). Pre and postmatch countermovement jump (CMJ), and handgrip performances were compared (p < 0.05). The match imposed a high load (HR > 85% of individual HRmax = 92 ± 12%; La = 6.7 ± 2.5 mmol·L⁻¹) on athletes. After the match, better (p < 0.0001) CMJ (men: 43.9 ± 5.2 cm; women: 30.8 ± 2.3 cm) and worst (p = 0.006) handgrip performances (men: 459 ± 87 N; women: 337 ± 70 N) were found with respect to prematch ones (CMJ: men = 40.8 ± 4.9 cm, women = 28.2 ± 2.5 cm; handgrip: men = 486 ± 88 N, women: 337 ± 70 N). Results indicate that the intermittent activity of the Taekwondo competition elicits a high neuromuscular activation of the lower limbs. Instead, the decreases in grip strength could be because of the repeated concussions on the upper limbs used to protect from the opponent's kicks and punches directed toward the scoring area of the torso. Practically, these results urge coaches to structure training sessions that enable athletes to maintain their upper limb strength during their match.

Effects of different recovery interventions on anaerobic performances following preseason soccer training.

In the preseason soccer training, morning and afternoon training sessions often are scheduled daily. The high frequency of training sessions could place heavy strain on biological systems, and it is necessary to apply proper recovery strategies for improving the players' capability to regain an adequate working state for subsequent training units. However, the effect of recovery interventions following soccer training units is debatable, due to a lack of studies performed in field situations. The aim of this study was to examine, during a 21-day preseason soccer training, the most effective recovery intervention (i.e., passive, dry-aerobic exercises, water-aerobic exercises, electrostimulation) on anaerobic performances (i.e., squat jump, countermovement jump, bounce jumping, and 10-m sprint) and subjective ratings (i.e., perceived exertion and muscle pain), with the conditions before the intervention controlled and standardized. Twelve young (age: 18.1 +/- 1.2 years) elite soccer players participated. Data were collected on 4 occasions 2 days apart and at the same time of the day. Activity and dietary intake were replicated on each occasion. After baseline measurements, participants performed a standardized training during which their heart rates and ratings of perceived exertion were recorded. This was followed by a 20-minute recovery intervention. After a 5-hour rest, athletes' ratings of muscle pain were recorded prior to a second test session. There were no significant differences in exercise intensities and baseline anaerobic performances. Significantly (p < 0.01) better performances were observed in the afternoon. Although no main effect of recovery intervention was observed on anaerobic performances, dry-aerobic exercises (0.6 +/- 0.9) and electrostimulation (0.6 +/- 1.2) were more beneficial (p < 0.01) than water-aerobic exercises (2.1 +/- 1.1) and passive rest (2.1 +/- 1.7) for reducing muscle pain, which could affect the player's working ability.