The increase of low-cost technology for underwater filming has made quantitative analysis an affordable resource for swimming coaches on a frequent basis. In this context, a synthesis of the kinematic determinants of underwater undulatory swimming (UUS) seems to be lacking. The aim of the present study was to synthesise the scientific evidence on the kinematic characteristics of competitive swimmers during UUS and the main kinematic determinants of UUS performance, as well as to summarise the main methodological considerations for UUS kinematic analysis. A systematic literature search was performed through four electronic databases following the PRISMA guidelines and STROBE for evaluating the quality of the included studies. Twenty-three research studies from the first search and two from the second search were finally considered. In total, 412 competitive swimmers (321 males and 91 females) with a performance standard of international B (11%), national (51%), or regional (35%) level were analysed. Most studies focused on a two-dimensional analysis of the ventral UUS performed from a push start and filmed 6–12 m from the starting wall. Kinematic analysis of UUS included kicking parameters (kicking length, frequency, and amplitude) as well as selected segmental kinematics in 76% of studies and the analysis of UUS performance determinants in 36%. Information about the determinants of UUS performance was inconsistent due in part to inconsistencies in the definition of kinematic parameters. Further research studies where automatic motion capture systems are applied to the analysis of UUS on the aforementioned conditions should be conducted.

Background: During the repetitive execution of the swimming strokes, the muscles responsible for the internal rotations of the shoulders tend to become stronger compared to the muscles that oppose these movements. The aim of this study was to analyse the effect of a strengthening program for the shoulder rotator muscles using elastic band exercises in a diagonal Kabat pattern (D2 for flexion) in swimmers, to develop an effective, quick and easy-to-implement protocol for preventive training routines.Methods: A randomized controlled trial design was carried out. Internal and external rotation range of movement, isometric strength of the muscles responsible for internal and external rotation of the shoulder, scapular movements, was measured at the beginning of the study and after 8 weeks post-intervention. A total of 22 male swimmers participated in the study and were randomly assigned to either an experimental group (n = 11) or a control group (n = 11). The experimental group underwent a 8-week shoulder-strength program using elastic bands, while the control group focused on aquatic training.Results: The strength-training program resulted in an improvement in the isometric strength of the muscles responsible for external rotation and a better balance between the shoulder rotator muscles in the experimental group. However, these improvements have not been significant (p > 0.05).Conclusion: The strengthening exercise program showed minimal improvement in shoulder rotation strength and range of motion. These findings suggest that the prescribed shoulder-strengthening exercise could be a quick-beneficial dry-land training option to improve external rotation shoulder strength or range of motion, but more studies with larger sample sizes and more weeks of treatment are needed to determine the efficacy of this protocol.

Backstroke swimmers display the greatest contribution of underwater kicking during the swimming race distances, but, surprisingly, there is little evidence of how kicking kinematics in the dorsal position should be performed. The aim of the present study was to examine the kinematic characteristics of competitive swimmers during underwater undulatory swimming in the dorsal position, with special attention to the swimmers’ gender, the level of skill, and kick order. Forty-one national-level swimmers (27 females and 14 males) were filmed from an underwater lateral view while performing a 25-m backstroke from a push start, and they were divided into fast and slow groups according to their kicking velocity. Direct linear algorithms were employed to reconstruct the two-dimensional kinematic characteristics of the first and final kicks of the underwater section. There were no differences between males and females in kicking performance when data were normalised to the swimmers’ height. However, swimmers in the fast-kicking group were distinguished by a greater kicking frequency (η²: 0.15) and specific segmental kinematics related to a lower knee range of motion. Swimmers decreased kicking velocity (η²: 0.47) in addition to the kicking frequency (η²: 0.31) and length (η²: 0.16), but increased the kicking amplitude (η²: 0.11) between the first and the final kicks. Changes in kicking segmental kinematics were more related to modification in body orientation during the underwater trajectory than to the kicking motion itself. These results provide the first solid evidence of how swimmers should kick for better performance in dorsal underwater swimming.

(1) Background: The aim of the present research is to describe the kinematic characteristics of push start in competitive swimmers and to examine the role of the push start sub-phases on the overall start performance. (2) Methods: Seventy-four swimmers (33 males and 41 females) of national and international level performed one 25 m trial at maximum velocity with a push start at butterfly, backstroke and/or front-crawl techniques and were filmed with two sequential underwater cameras during the glide, leg kicking, transition and surface swimming phases. (3) Results: Backstroke starts showed greater emersion distances but slower times to 10 m than the remaining strokes. Distances and average velocities in each of the start sub-phases predicted the overall push start performance (times to 10 m) on the butterfly (R²: 0.50) and backstroke (R²: 0.58) strokes, with the velocity of the leg kicking phase having a statistical effect on both regression analysis and the glide and transition phases in backstroke. (4) Conclusions: Push starts performed in a dorsal body position seemed to present kinematic differences with ventral techniques and a greater technical complexity with all glide, leg kicking and transition sub-phases meaningfully impacting the overall push start performance. This should be considered when executing the daily training repetitions with swimmers in water.

Introduction: The objective of this paper is to study the research trends in the sport modality of artistic swimming and to analyse the scientific production regarding this sport.Methods: Two hundred and twenty articles related to the theme were selected after a search in the PubMed, SPORTDiscus and Web of Science databases and some additional records, using the theme “synchronised swimming OR artistic swimming” up to December 2022. The variables scrutinized were the following: (1) title, (2) discipline, (3) type, (4) sample size and (5) sporting level.Results: The results indicate that (1) 53.6% of the artistic swimming articles were case studies, (2) 23.2% talked about physiology, (3) 32.7% had a sample of 11–50 participants, and (4) 30.9% of the sample was elite/international swimmers.Discussion: Over the years there has been a considerable increase in studies on artistic swimming; the topics of greatest interest in artistic swimming have been physiology, sports performance and injuries. Even so, it seems that for the moment artistic swimming has little impact, probably due to its status as a minority sport and it having limited social and economic impact.

Objective: The aim of this investigation was to compare the thickness of the deep local muscles in the neck region, as well as local and widespread sensitivity and functionality, between individuals with migraine and healthy control subjects. Methods: An observational study was carried out in accordance with the STROBE statements. The flexor longus colli and multifidus, two neck-stabilizing muscles, were measured using B-mode ultrasound imaging. The upper trapezius, masseter, temporalis, anterior tibialis, and median nerve all underwent bilateral pressure-pain threshold (PPT) assessments. The statistical program SPSS 29.0 was used to implement the Mann–Whitney U test and Chi-squared test. Spearman Rho was utilized to establish the correlations between the variables. Results: Sixty participants were enrolled in the study. The subjects, who were matched in terms of age, gender, and body mass index (BMI), were equally divided into migraine and control groups. No significant differences between the groups were found in the multifidus CSA regarding both sides at rest (right: p = 0.625; left: p = 0.203). However, in contraction, the multifidus CSA showed a significant decrease on the left side in the patients with migraine compared to the controls (p = 0.032), but no significant differences were found in the right multifidus CSA in contraction between the two groups (p = 0.270). In comparison to the healthy volunteers, the migraine sufferers showed a substantial reduction in CSA in the longus colli muscle on both the left side (p = 0.001) and the right side at rest (p = 0.003), as well as in the CSA of the left longus colli in contraction (p < 0.001). Furthermore, the migraine patients showed significantly lower PPT compared to the healthy subjects in local and widespread areas bilaterally. All the parameters revealed higher sensitization in the migraine group in the following areas: the right and left temporal regions (p < 0.001), the right and left upper trapezius (p < 0.001 and p < 0.01, respectively), the right and left masseter muscles (p < 0.01), the right and left median nerves (p < 0.001 and p < 0.01, respectively), and the right and left anterior tibialis muscles (p < 0.001). In terms of the craniocervical flexion test (CCFT), the migraine patients demonstrated significantly lower values than the healthy subjects (p < 0.001). A moderate positive correlation was noted between the PPT in the right temporalis muscle and that in the left longus colli and the right multifidus in contraction. The PPT in the right temporalis muscle also exhibited a positive correlation with the CCFT, although this correlation was low. Between the PPT values, the upper trapezius on both sides showed a moderate positive correlation with the median nerve bilaterally. Conclusions: This research suggests that individuals with migraine may experience local and widespread pain sensitization. A decrease in functionality due to the low muscle endurance of the deep cervical muscles is also accompanied by low values of muscle thickness in contraction. These findings may help to select more accurate treatment approaches for patients with migraine.