Validation and Application of Two New Core Stability Tests in Professional Football

Exploring the relationship between core stability and vertical jump in recreationally active male college students based on a suite of novel core stability assessments

Various assessments have contributed to inconsistent findings regarding the correlation between core stability and vertical jumps. Therefore, this study aimed to re-examine this correlation based on novel core stability assessments. Twenty-one recreationally active male college students (age, 21.7 ± 2.1 years; stature, 174.9 ± 6.7 cm; body mass, 67.7 ± 7.8 kg; leg length, 88.9 ± 4.8 cm; arm length, 87.8 ± 4.0 cm) participated in this experiment. Core stability was divided into static and dynamic core stabilities, with the static core stability measured using the Eight-Level Prone Bridge and Five-Level Side Bridge tests and the dynamic core stability measured using the Y Balance Test (YBT). These tests comprehensively evaluate core stability as it is defined. Kinematic and kinetic data on vertical jumps were collected to provide process information beyond the outcome performance. Subsequently, these data were correlated with core stability for a deeper insight into the relationship between core stability and the process and outcome performance of vertical jumps. The main results revealed that the Eight-Level Prone Bridge demonstrated moderate to substantial correlations with Δ F y ‾ , Δ I y , Δ D l e f t k n e e z , and Δ D l e f t a n k l e y (-0.62 ≤ r ≤ 0.52); the Five-Level Side Bridge exhibited moderate correlations with Δ F x ‾ , Δ F y ‾ , Δ I x , Δ I y , Δ D l e f t k n e e z , and Δ D l e f t a n k l e y (-0.52 ≤ r ≤ 0.59); YBT displayed moderate correlations with F z ‾ , F l e f t z ‾ , Δ D l e f t a n k l e y , Δ D r i g h t a n k l e y , Δ D l e f t a n k l e z , Δ D r i g h t a n k l e z , NΔ T a n k l e y ‾ , and N T l e f t a n k l e z ‾ (-0.54 ≤ r ≤ 0.54) during the propulsive phase of vertical jumps. However, no significant correlations were observed between static/dynamic core stability and jumping height. Therefore, individuals with greater core stability should experience improved process performance (better movement quality), although this benefit is ineffective in translating into jumping height improvement due to impaired explosive features. Coaches may consider core stability in training to trigger an improved process performance of the vertical jump when the technique is the key issue to be solved, although future studies are required to verify this further.

A Prospective, Open-Label Study to Evaluate Functional Changes Following Electromagnetic Muscle Stimulation of Abdominal Muscle

Background

Electromagnetic muscle stimulation (EMMS) is an effective, well-tolerated noninvasive body contouring treatment for strengthening, toning, and firming the abdomen.

Objectives

In this study, functional changes following abdominal EMMS treatment wereevaluated.

Methods

In this prospective, open-label study, adults received 8 abdominal EMMS treatments (2 treatments on nonconsecutive days/week over 4 weeks). Follow-ups occurred 1 month (primary endpoint), 2, and 3 months postfinal treatment. Effectiveness endpoints included improvements from baseline on Body Satisfaction Questionnaire (BSQ; primary endpoint), core strength (timed plank test), abdominal endurance (curl-up test), and Subject Experience Questionnaire (SEQ). Safety was evaluated throughout.

Results

Sixteen participants (68.8% female) were enrolled, with a mean age of 39.3 years and a mean BMI of 24.4 kg/m²; 14 participants completed the study per protocol. Mean BSQ scores were significantly improved from baseline (27.9) to the 1-month follow-up (36.6; P < .05). Core strength and abdominal endurance were significantly greater at the 1-, 2-, and 3-month posttreatment time points than at baseline (P < .05). Frequently cited reasons for seeking EMMS treatment included a desire to feel stronger (100%; n = 14/14) and to improve athletic performance (100%; n = 14/14). SEQ responses 3 months posttreatment showed that most participants reported feeling stronger (92.9%) and motivated to receive additional EMMS treatments (100%) and work out to maintain treatment results (100%). The majority of participants (>78%) reported being "satisfied" or "very satisfied" with abdominal treatment 1 month posttreatment. One device- and/or procedure-related adverse event of menstrual cycle irregularity was reported in 1 participant and was mild in severity.

Conclusions

EMMS treatment of the abdomen is associated with functional strength improvements and high patient satisfaction.

Level of Evidence 4

Strength and Power-Related Measures in Assessing Core Muscle Performance in Sport and Rehabilitation

While force-velocity-power characteristics of resistance exercises, such as bench presses and squats, have been well documented, little attention has been paid to load, force, and power-velocity relationships in exercises engaging core muscles. Given that power produced during lifting tasks or trunk rotations plays an important role in most sport-specific and daily life activities, its measurement should represent an important part of the test battery in both athletes and the general population. The aim of this scoping review was 1) to map the literature related to testing methods assessing core muscle strength and stability in sport and rehabilitation, chiefly studies with particular focus on force-velocity-power characteristics of exercises involving the use of core muscles, 2) and to identify gaps in existing studies and suggest further research in this field. The literature search was conducted on Cochrane Library databases, Scopus, Web of Science, PubMed and MEDLINE, which was completed by SpringerLink, Google Scholar and Elsevier. The inclusion criteria were met in 37 articles. Results revealed that among a variety of studies investigating the core stability and core strength in sport and rehabilitation, only few of them analyzed force-velocity-power characteristics of exercises involving the use of core muscles. Most of them evaluated maximal isometric strength of the core and its endurance. However, there are some studies that assessed muscle power during lifting tasks at different loads performed either with free weights or using the Smith machine. Similarly, power and velocity were assessed during trunk rotations performed with different weights when standing or sitting. Nevertheless, there is still scant research investigating the power-velocity and force-velocity relationship during exercises engaging core muscles in able-bodied and para athletes with different demands on stability and strength of the core. Therefore, more research is needed to address this gap in the literature and aim research at assessing strength and power-related measures within cross-sectional and intervention studies. A better understanding of the power-force-velocity profiles during exercises with high demands on the core musculature has implications for designing sport training and rehabilitation programs for enhancement of athletes' performance and/or decrease their risk of back pain.

Functional and Anthropometrical Screening Test among High Performance Female Football Players: A Descriptive Study with Injury Incidence Analysis, the Basque Female Football Cohort (BFFC) Study

The main objectives of the present study were to describe the injury incidence and to analyze the anthropometric and physical characteristics of players from three high-level women's football teams. The present study involved 54 female football players (21.9 ± 4.9 years old) from three different teams competing in the Spanish Reto Iberdrola-Segunda División PRO league. A battery of tests was carried out to determine the anthropometric and physical performance characteristics of the players along with an injury incidence record during a full competitive season. The obtained results showed that there was a high incidence of injury, as 38% of the players suffered some type of injury during the season (range 1-5; 1.75 ± 1.02 injuries per player). Injuries occurred in both matches and during training at a similar percentage (48.6 vs. 51.4%), and the majority of the registered episodes were graded as moderate or severe injury types (60%). Players suffering from an injury accumulated a total of 1587 chronological days off work due to injury during the season, with a recurrence rate of 55%. Considering the high incidence of injury, and the injury burden and the reinjure rate observed in this research, it seems necessary to apply the most efficient prevention and recovery measures possible in these female football teams. These descriptive data could serve athletic trainers and medical staff of female football teams to better understand their own screening procedure-derived data.