The short-term effect of swimming training load on shoulder rotational range of motion, shoulder joint position sense and pectoralis minor length

The Effects Of Differing Density Of Swim-Training Sessions On Shoulder Range Of Motion and Isometric Force Production In National and University Level Swimmers

Background

Well-developed physical qualities (i.e., greater load capacity) in athletes can provide protection against injuries. Although higher competitive level swimmers have more developed physical qualities, no studies have investigated how physical qualities of the shoulder respond to a swim-training session in different competitive levels.

Purpose

To compare baseline shoulder external rotation range of motion (ER ROM) and isometric peak torque of the shoulder internal rotators (IR) and external rotators (ER) between national and university level swimmers with differing training volumes. To compare the post-swim changes of these physical qualities between groups.

Study design

Cross-sectional.

Methods

Ten male swimmers (age= 18.7 ± 1.2 years) were divided into high-load (N= 5 national-level, weekly swim-volume= 37.0 ± 2.7 km) and low-load groups (N= 5 university-level, weekly swim-volume= 6.8 ± 1.8 km). For each group, shoulder active ER ROM and isometric peak torque of the shoulder IR and ER were measured before and immediately after a high-intensity swim-training session (for each group, the hardest swim-session of the week was analyzed). The results were evaluated by the level of significance (p-value), effect size, and whether changes exceeded the measurement error.

Results

University-level swimmers had lower baseline ER torque (p= 0.006; d= 2.55) and IR torque (p= 0.011; d= 2.42) than national-level swimmers. For post-swim analysis, ER ROM decreased more in university swimmers (change= -6.3° to -8.4°; d= 0.75-1.05) than national counterparts (change= -1.9° to -5.7°; d= 0.43-0.95). Greater drops in rotation torque were found in university swimmers (IR change= -15% to -21.0%; d= 0.83-1.66; ER change= -9.0% to -17.0%; d= 1.14-1.28) compared to national swimmers (IR change= -10.0% to -13.0%; d= 0.61-0.91; ER change= -3.7% to -9.1%; d= 0.50-0.96). The average change of all tests in university swimmers exceeded the minimal detectable change (MDC), whereas in national level swimmers some tests exceeded the MDC. Despite this, only post-swim ER torque in the dominant side (p= 0.003; d= 1.18) was significantly lower in university swimmers (possibly due to the small sample size).

Conclusions

University swimmers have less baseline shoulder external and internal rotator torque and had greater drops of all shoulder physical qualities after a swim-training session, which may have implications for injury risk. However, due to the sample size, the results have to be interpreted with caution.

Level of evidence

3.

Scapulohumeral kinematics and neuromuscular control during scaption are associated with passive stiffness and strength of periscapular muscles in competitive adolescent swimmers

The passive stiffness and strength of periscapular muscles may affect scapulohumeral control, especially in overhead athletes due to sports-specific training. This study tried to assess the relationship between the passive stiffness and strength of periscapular muscles, scapulohumeral kinematics and neuromuscular control during scaption in swimmers. Ten male adolescent competitive front-crawl swimmers were recruited. The passive stiffness and strength of periscapular muscles were measured in standard postures by a hand-held myotonometer and dynamometer, respectively. Surface electromyography and electromagnetic tracking systems were synchronized to record the muscle activities and scapulohumeral kinematics during scaption. Correlations between the passive stiffness or strength of periscapular muscles and the kinematics or muscle activity were examined by Spearman's rank correlation coefficient. The maximal strength of periscapular muscles correlated positively with the ranges of upward and external rotation of the scapula and negatively with muscle activity during scaption. Passive stiffness of periscapular muscles was associated with the downward rotation of the scapula and triggered an increase in muscle activity. Increased passive stiffness or decreased strength in the periscapular muscles may affect their role in controlling the scapular rotation and contribute to compensation from adjacent muscles. Our findings suggest that when attempting to evaluate scapular behavior, it may be beneficial to examine muscle strength and passive stiffness of periscapular muscles.

Non-shoulder Injuries in Swimming: A Systematic Review

OBJECTIVE

The shoulder is the most common injury in swimming, followed by the knee and spine. The repetitive nature of swimming training may predispose a swimmer to injury. Several risk factors have been previously identified, but the level of evidence and level of certainty that these risk factors predispose a swimmer to injury risk has yet to be evaluated critically in a systematic review.

DESIGN

Systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

DATA SOURCES

Data were obtained through PubMed, Cochrane, and Google Scholar. The database search was limited to articles that were published between January 1980 and December 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Level I, II, and III studies were included in this review. All studies must have been conducted in swimmers or swimming, a description of the specific pathology and provide at least one identified risk factor with an association (P < 0.05).

RESULTS

A total of 19 critically appraised articles identified 28 potential risk factors for musculoskeletal injuries in swimmers. The risk factors were grouped by the anatomical region: neck and back, pelvis and hip, and the knee. Only 2 risk factors were appraised at a moderate level of certainty, both occurring in the knee. The remaining 26 identified risk factors were appraised at a low level of certainty. There is a clear lack of research surrounding nonshoulder injuries in swimmers.

Cumulative Effects of a Week's Training Loads on Shoulder Physical Qualities and Wellness in Competitive Swimmers

BACKGROUND

Competitive swimmers are exposed to high training loads, which can contribute to the development of shoulder pain. There is a lack of research investigating the interactions between the accumulation of training loads and factors associated to shoulder pain in swimmers.

PURPOSE

The primary objective was to analyze the changes in shoulder physical qualities and wellness factors over a week of training in competitive swimmers. A secondary objective was to compare the changes in these variables between different swim-training volumes performed during the week.

DESIGN

Cross-sectional.

METHODS

Thirty-one national and regional-level swimmers were included (18 females, 13 males; age= 15.5 ± 2.2 years). Active shoulder external rotation (ER) range of motion (ROM), shoulder-rotation isometric torque, and wellness factors using the Hooper questionnaire were measured twice over the week: a baseline measurement (before Monday´s training session) and a follow-up during the week. Participants were divided into a high-volume group (HVG) and low-volume group (LVG) based on the day follow-up was performed. HVL (n= 15) was tested at the end of the training week (after Saturday´s session) and LVG (n= 16) during the week (after Thursday or Friday´s session). Rating of perceived exertion (RPE) of the whole week was recorded after the follow-up session.

RESULTS

At follow-up, the LVG averaged a volume of 26.2 ± 2.2 km, whereas the HVG averaged a volume of 37.5 ± 3.7 km. LVG and HVG participants decreased active shoulder ER ROM on dominant (p= 0.002; p= 0.006) and nondominant sides (p= 0.001; p= 0.004), displayed increased muscular soreness (p= 0.001; p= 0.007) and worsened overall wellness (p< 0.001; p= 0.010). Fatigue (p= 0.008) and poor sleep quality were increased (p= 0.023) in HVG, but not in LVG. There were no changes in shoulder-rotation torque and stress in any group. Regarding between-groups differences, only weekly RPE was higher (p= 0.004) in HVG.

CONCLUSIONS

The accumulation of training loads over the week negatively affect physical and wellness factors. Greater swim-volumes were associated with an increase perception of training loads. The regular monitoring of multiple factors to assess swimmers' response to training might be necessary.

LEVEL OF EVIDENCE

3.

Training Intensity and Shoulder Musculoskeletal Physical Quality Responses in Competitive Swimmers

CONTEXT

Shoulder pain is the main cause of missed or modified training in competitive swimmers. Shoulder musculoskeletal maladaptations occur to some extent as a consequence of training loads during swimming that may increase the risk of shoulder injury. Further evidence is needed to understand the training intensities at which these maladaptations occur.

OBJECTIVE

To determine the acute effect of training intensity on the shoulder musculoskeletal physical qualities associated with shoulder injury in competitive swimmers.

DESIGN

Cross-sectional study.

SETTING

Indoor swimming pool.

PATIENTS OR OTHER PARTICIPANTS

Sixteen asymptomatic national- and regional-level swimmers (7 females, 9 males; age = 14.6 ± 3.9 years, height = 160.5 ± 12.7 cm, mass = 55.3 ± 12.5 kg).

MAIN OUTCOME MEASURE(S)

Bilateral active shoulder-rotation range of motion (ROM), joint position sense, latissimus dorsi length, combined elevation test, and shoulder-rotation isometric peak torque and handgrip peak force normalized to body weight were measured before and immediately after low- and high-intensity swim-training sessions. The intensity of the sessions was determined by the distance swum over or at the pace threshold and confirmed by the swimmer's rating of perceived exertion.

RESULTS

After the high-intensity training session, shoulder external-rotation ROM (dominant side: P < .001, change = -7.8°; d = 1.10; nondominant side: P = .002, change = -6.5°, d = 1.02), internal-rotator isometric peak torque (dominant side: P < .001, change = -11.4%, d = 0.42; nondominant side: P = .03, change = -6.6%, d = 0.20), and external-rotator isometric peak torque (dominant side: P = .004, change = -8.7%, d = 0.27; nondominant side: P = .02, change = -7.6%, d = 0.25) were reduced. No changes were found in any of the outcome measures after the low-intensity session.

CONCLUSIONS

Shoulder active external-rotation ROM and rotation isometric peak torque were decreased immediately after a high-intensity training session, possibly increasing the risk of injury during subsequent training. Monitoring these variables may help practitioners adjust and manage training loads to decrease the risk of shoulder injury.

An Updated Review of the Epidemiology of Swimming Injuries

OBJECTIVE

To carry out a systematic review to update the scientific evidence on the incidence and prevalence of injuries in the swimming discipline, as well as the location, type, and mechanism of the injuries, and to assess whether studies are meeting methodological recommendations for data collection and injury surveillance. TYPE: Analytical-Systematic review.

LITERATURE SURVEY

The databases of PubMed and Sportdiscus were used to search for studies that describe the epidemiology of injuries in adult swimmers between 2010 and March 2020.

METHODOLOGY

Of the 864 articles identified, 14 studies were finally included in this review. The methodological quality of the studies was analyzed with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) scale and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.

SYNTHESIS

The results showed a high prevalence of shoulder, knee, and lower back injuries among swimmers due to overuse. These injuries were mainly short-term tendon muscles; there were reported data differences between genders.

CONCLUSIONS

Despite the publication of an injury surveillance single and multisport events document and a consensus on data collection and injury surveillance in swimming, there are huge methodological limitations that do not allow firm conclusions. As such, more epidemiological studies following guidelines for data collection and injury surveillance are needed to establish differences by gender, age group, and swimming stroke.

Low Range of Shoulders Horizontal Abduction Predisposes for Shoulder Pain in Competitive Young Swimmers

The prevalence of shoulder pain (SP) among competitive swimmers is high, and may profoundly restrict their ability to compete. This prospective cohort study investigated the association between 3 blocks of performance factors (anthropometric characteristics, sport experience and training regimen) and the presence of SP. The aims of the present study were: (a): to determine the profile of shoulder flexibility in young swimmers, (b) to analyze whether a restricted range of movement (ROM) could be a predictor of subsequent SP in young swimmers. 24 competitive young swimmers were measured in the 2016 pre-season. Measures of passive maximal shoulder extension (SE), flexion (SF), horizontal abduction (SHAB), abduction (SAB), horizontal adduction (SHADD), external (SER) and internal (SIR) rotation ROMs were taken. SP was prospectively monitored during the subsequent season using questionnaires. The data was analyzed via a binary logistic regression and ROC curves were calculated. At the follow-up, 16 swimmers (50%) had developed unilateral SP. Only reduced SHAB ROM was associated with SP [SP group 36.6° vs. pain-free group 41.5°; p = 0.005, d = -0.96 (moderate effect sizes)]. Using the coordinates of the curves, the angle of SHAB ROM that most accurately identified individuals at risk of developing SP was determined to be 39° (sensibility 0.656 and 0.375 specificity). Swimmers with limited ROM (≤39°) have 3.6 times higher risk of developing SP than swimmers with normal ROM (>39°). This study clearly shows that low range of SHAB is a risk factor for developing SP in competitive young swimmers. In the studied data, a SHAB range of 39° was found to be the most appropriate cut-off point for prognostic screening.