Greater Lumbar Extension During Dolphin Kick and Psoas Major Tightness in Swimmers With Low Back Pain

Changes in Shoulder and Lumbar Injury Incidence in Swimmers After Physical Examination and Exercise Programs

Background

Previous injury and physical examination data collected by a physiotherapist were reviewed to investigate the causes of injury among competitive swimmers. Each swimmer received an injury improvement exercise program based on their injury history and physical examination findings.

Purpose

The purpose of this study was to identify trends in the number of shoulder and lumbar injuries and discern the effectiveness of exercise programs in swimmers. The authors hypothesize that these efforts would decrease injury rates.

Study Design

Observational Cohort study.

Methods

Thirty-one male high school and college student swimmers underwent a physical examination. Previous injury was considered as pain that lasted for > three weeks or that caused the participant to stop practicing. A questionnaire was administered to all swimmers at the beginning of the study and one year later. The questionnaire assessed the number of injuries sustained and the daily practice hours over the previous year. The injury rate at the first examination and one-year followup was calculated as the number of injury incidents divided by the total number of player hours (1 h of practice is equivalent to 1) for one year, multiplied by 1,000 to obtain the injury rate per 1,000 hours (1000 player hours: 1,000 ph). Shoulder and hip exercise programs were prescribed based on measurement results and previous research.

Results

The numbers of injuries seen in the group were 12 shoulder and six lumbar at the first examination, and two shoulder and one lumbar at the one-year followup. The 1,000 ph (95% confidence interval) values were 0.32 (0.13-0.50) and 0.16 (0.03-0.29) at the first examination and 0.05 (0.00-0.12) and 0.03 (0.00-0.07) at the one-year followup for the shoulder and lumbar areas, respectively.

Conclusions

The results indicates that exercise programs prescribed after a physical examination may reduce the incidence of injuries in male swimmers over the course of a year.

Level of Evidence

Level 3.

Swimming Anatomy and Lower Back Injuries in Competitive Swimmers: A Narrative Review

CONTEXT

Competitive swimmers are at high risk of overuse musculoskeletal injuries due to their high training volumes. Spine injuries are the second most common musculoskeletal injury in swimmers and are often a result of the combination of improper technique, high loads on the spine in strokes that require hyperextension, and repetitive overuse leading to fatigue of the supporting trunk muscles. The purpose of this review is to summarize the current evidence regarding swimming biomechanics, stroke techniques, and common injuries in the lumbar spine to promote a discussion on the prevention and rehabilitation of lower back injuries in competitive swimmers.

EVIDENCE ACQUISITION

From a PUBMED/MEDLINE search, 16 articles were identified for inclusion using the search terms "swimming," "low back" or "lumbar," and "injury" or "injuries."

STUDY DESIGN

Narrative review.

LEVEL OF EVIDENCE

Levels 4 and 5.

RESULTS

The trunk muscles are integral to swimming stroke biomechanics. In freestyle and backstroke, the body roll generated by the paraspinal and abdominal muscles is integral to efficient stroke mechanics by allowing synergistic movements of the upper and lower extremities. In butterfly and breaststroke, the undulating wave like motion of the dolphin kick requires dynamic engagement of the core to generate repetitive flexion and extension of the spine and is a common mechanism for hyperextension injuries. The most common lower back injuries in swimming were determined to be lumbar strain, spondylolysis and spondylolisthesis, facet joint pain, and disc disease. Most overuse swimming injuries can be treated conservatively with physical therapy and training adjustments.

CONCLUSION

Managing swimmers with low back pain requires a basic knowledge of swimming technique and a focus on prevention-based care. Since most swimming injuries are secondary to overuse, it is important for providers to understand the mechanisms underlying the swimming injury, including an understanding of the biomechanics involved in swimming and the role of spine involvement in the 4 strokes that assist in stabilization and force generation in the water. Knowledge of the biomechanics involved in swimming and the significant demands placed on the spinal musculoskeletal system will aid the clinician in the diagnosis and management of injuries and assist in the development of a proper rehabilitation program aimed at correction of any abnormal swimming mechanics, treatment of pain, and future injury prevention.

STRENGTH OF RECOMMENDATIONS

B. Recommendation based on limited quality or inconsistent patient-oriented evidence.

Ultrasound elastography of back muscle biomechanical properties: a systematic review and meta-analysis of current methods

OBJECTIVES

To report the current elastography methods used to quantify back muscles' biomechanical characteristics in patients with musculoskeletal disorders (MSKd) and inform on their reliability, validity, and responsiveness.

METHODS

MEDLINE, Embase, CINAHL, Cochrane library and grey literature were consulted. Predefined criteria allowed for study selection and data extraction. The quality of evidence was rated using the COSMIN tool. Data were meta-analyzed in terms of pooled intraclass correlation coefficient (pICC) for reliability and pooled standardized mean difference (pSMD) for validity and responsiveness. Heterogeneity was assessed.

RESULTS

Seventy-nine studies were included in the meta-analysis (total number of participants N = 3178). Three elastography methods were identified: strain imaging (SI; number of cohorts M = 26), shear wave imaging (SWI; M = 50), and vibration sonoelastography (VSE; M = 3). Strain imaging and SWI studies reported good reliability measurement properties (pICC > 0.70) and a medium pSMD (0.58 for SI and 0.60 for SWI; p ≤ 0.020) in discriminating MSKd from controls' condition (validity). Strain imaging studies reported a medium pSMD (0.64; p = 0.005) in detecting within-group changes over time, whereas SWI pSMD was very high (1.24; p = 0.005). Only SWI reported significant but small pSMD (0.30; p = 0.003) in detecting between-group changes over time. The small number of VSE studies could not be meta-analyzed. Heterogeneity was high (I-squared > 90%; p < 0.001).

CONCLUSIONS

Elastography presents good reliability results and a medium pSMD in discriminating MSKd from control conditions. Responsiveness data suggest detectable changes within groups over time using SI and SWI, calling for long-term longitudinal studies. Assessing changes between groups over time using elastography still needs to be proven. Highly significant heterogeneity limits meta-analytic results.

CRITICAL RELEVANCE STATEMENT

While still in its early-stage exploration phase, musculoskeletal ultrasound elastography may reliably quantify back muscles' biomechanics in asymptomatic individuals, moderately discriminate back musculoskeletal disorders and detect biomechanical changes over time in these conditions, calling for long-term longitudinal studies.

KEY POINTS

Ultrasound elastography is reviewed for back pain and related musculoskeletal disorder assessments. Growing literature supports good reproducibility, some validity and responsiveness. Back muscle elastography considers assumptions calling for standardized protocols.

Reliability of Ultrasound Shear Wave Elastography for Evaluating Psoas Major and Quadratus Lumborum Stiffness: Gender and Physical Activity Effects

OBJECTIVE

We aimed to assess the reliability of quantifying psoas major (PM) and quadratus lumborum (QL) stiffness with ultrasound shear wave elastography (SWE), and to explore the effects of gender and physical activity on muscle stiffness.

METHODS

Fifty-two healthy participants (18-32 y) were recruited. To determine reliability, 29 of them underwent repeated SWE measurements of PM and QL stiffness by an operator on the same day. The intra-class correlation coefficients (ICC3,1), standard error of measurement (SEM) and minimal detectable change with 95% confidence interval (MDC95) were calculated. The rest participants underwent a single measurement. Two-way MANCOVA was conducted for the effects of gender and physical activity on muscle stiffness.

RESULTS

The observed reliability for PM (ICC3,1 = 0.89-0.92) and QL (ICC3,1 = 0.79-0.82) were good-to-excellent and good, respectively. The SEM (kPa) was 0.79-1.03 and 1.23-1.28, and the MDC95 (kPa) was 2.20-2.85 and 3.41-3.56 for PM and QL, respectively. After BMI adjustment, both gender (PM: F = 10.15, p = 0.003; QL: F = 18.07, p < 0.001) and activity level (PM: F = 5.90, p = 0.005; QL: F = 6.33, p = 0.004) influenced muscle stiffness. The female and inactive groups exhibited higher stiffness in both muscles.

CONCLUSION

SWE is reliable for quantifying the stiffness of PM and QL. Female and physical inactivity may elevate PM and QL stiffness, underscoring the importance of accounting for these factors in muscle stiffness investigations. Larger prospective studies are needed to further elucidate their effects.

The effect of swimming on the body posture, range of motion and musculoskeletal pain in elite para and able-bodied swimmers

BACKGROUND

Elite swimmers may be predisposed to disturbances in the range of motion (ROM) of hip joints and spinal curvatures, which are a factor that induces body's compensatory mechanisms that may have an impact on sports training, athletic performance and health. This study aimed to identify compensatory mechanisms in body posture of elite Para and able-bodied swimmers (spinal curvatures, ROM), to indicate the dominant locations of the compensatory mechanisms in the groups of Para and able-bodied athletes, and to identify and compare the prevalence and location of musculoskeletal pain from the last week and the last six months in the context of compensatory mechanisms.

METHODS

Thirty-five (nF = 8; nM = 27; age = 20.51 ± 4.24) elite Para and able-bodied swimmers from the Polish national team took part in the study and were divided into: study group (SG) of Para swimmers and control group (CG) of able-bodied swimmers. Depth of the anteroposterior spinal curvatures and sagittal spinal mobility testing were evaluated with a Medi Mouse device. The prevalence and locations of musculoskeletal pain were assessed with a Nordic Musculoskeletal Questionnaire for the last seven days (NMQ-7) and the last six months (NMQ-6).

RESULTS

In both groups lumbar hypolordosis, anterior pelvic tilt and pain in the shoulders, lower back and hips/thighs (NMQ-7) were reported the most frequent. In SG several significant relationships were found between duration of sport-specific training experience (years) and depth of angle the lumbar lordosis, the depth of the angle of pelvic inclination the ROM in the lumbar spine and thoracic spine, what was not reported in CG.

CONCLUSIONS

Extrinsic compensatory mechanism was identified in both study groups, however only in SG it occurred as structural (depth of the angle of lumbar lordosis and pelvic inclination) and functional changes (ROM in the thoracic and lumbar spine) in the body posture. Internal compensatory mechanism was identified in SG, however external compensation showed only partially suppressive character regarding to internal compensation. The locations of the musculoskeletal complaints seems to result from both internal compensatory mechanism (SG) and continuous overload of the anatomy trains as a result of swimming training (SG, CG).

Association Between Nondominant Leg-Side Hip Internal Rotation Restriction and Low Back Pain in Male Elite High School Soft Tennis Players

CONTEXT

The incidence of low back pain (LBP) is high among high school male soft tennis players. In some sports for which the rotational component of the body is important, an association between restricted hip internal rotation of the nondominant leg and LBP has been reported; however, whether this association holds in soft tennis is unknown. Therefore, this study aimed to evaluate the association between hip internal rotation, hip external rotation, hamstring flexibility, iliopsoas flexibility, and LBP incidence.

DESIGN

This study was designed as a cross-sectional study, conducted at a sports training center.

METHODS

Participants comprised 113 male elite high school soft tennis players (age: 16.1 [0.7] y) from 9 elite-level teams. The main outcome measures were the hip internal and external rotation range of motion, hamstring flexibility on the straight leg raise test, and iliopsoas flexibility on the Thomas test. Multiple logistic regression analysis was performed to examine the influence of main outcomes on LBP incidence in the past 1 year.

RESULTS

A total of 35 participants had LBP (LBP group); 78 participants did not have LBP (non-LBP group). Multiple logistic regression analysis revealed that the odds ratio for height was 1.08 (95% confidence interval, 1.00-1.16; P = .043) and for the hip internal rotation range of motion in the nondominant leg was 0.90 (95% confidence interval, 0.85-0.95; P < .001), indicating significant associations with LBP.

CONCLUSION

Hip internal rotation range of motion in the nondominant leg and height were crucial factors related to LBP in male elite high school soft tennis players.

Determinants of the prevalence and location of musculoskeletal pain in elite Para athletes

The tendency for musculoskeletal complaints, injuries, and traumas remains significant among Para athletes. The aim of the study was to identify and verify the variables that impact the incidence and location of musculoskeletal pain in elite athletes with disabilities. It was assumed, that the type of disability and not the type of sport, or the type of injuries and traumas is the crucial determinant of the prevalence and location of musculoskeletal pain in Para athletes. A direct-participatory observation method was used in the study including both subjective (surveys questionnaires) and objective (anthropometric) methods of assessment. The study included 35 male and female elite Para athletes from the Polish national team (sitting volleyball [SG1: n = 21], para swimming [SG2 = 14]). Both groups of Para athletes mostly reported pain in the neck (37%), and the lower back (34%). The Spearman's rank-order correlation showed several large inversely proportional relationships between somatic parameters and the values in the Nordic Musculoskeletal Questionnaire from the last 7 days (NMQ-7) for SG2 and some moderate to large correlations between body adiposity index (BAI) and the prevalence of injuries, the total number of rehabilitation sessions, the number of humeral joint and fingers rehabilitation sessions, breaks from training over 4 weeks in SG1. In both groups relationships were found between the duration of Paralympic training and the number of injuries and rehabilitation sessions (R = -0.4; P < .02) and between the exclusion from training for less 4 and over 4 weeks (R = -0.4; P < .03). The age of the Para athletes correlated with the NMQ-7 (wrists) (R = 0.4; P < .01). Both duration of disability and the type and severity of the disability may be crucial determinants of the prevalence and location of pain in the musculoskeletal system in Para athletes. Sport-specific training seems to induce specific musculoskeletal complaints.

Physique, range of motion, and gross muscle strength in hemiplegic para swimmers: a cross-sectional case series

[Purpose] The physical functions related to swimming should be evaluated to enhance competitive performance and prevent sports injuries. This study aimed to determine the physique, range of motion, and gross muscle strength of the limbs among hemiplegic para swimmers. [Participants and Methods] Three male para swimmers with hemiplegia and five male para swimmers with impaired vision were included in the study. The limb circumference, range of motion, quadriceps flexibility, and gross muscle strength were evaluated. The hemiplegic swimmers and swimmers with impaired vision were compared using an unpaired t-test. [Results] The maximum values of the upper and forearm circumferences; the range of motion for shoulder flexion, external rotation, ankle dorsiflexion on the paretic side; and the single-leg sit-to-stand test of the dominant limb were significantly lower in hemiplegic swimmers than in swimmers with impaired vision. [Conclusion] Hemiplegic swimmers had decreased upper limb circumferences on the paretic limb; the range of motion for shoulder flexion, external rotation, and ankle dorsiflexion on the paretic limb; and muscle strength on the dominant lower limb.

Implementing Ultrasound Imaging for the Assessment of Muscle and Tendon Properties in Elite Sports: Practical Aspects, Methodological Considerations and Future Directions

Ultrasound (US) imaging has been widely used in both research and clinical settings to evaluate the morphological and mechanical properties of muscle and tendon. In elite sports scenarios, a regular assessment of such properties has great potential, namely for testing the response to training, detecting athletes at higher risks of injury, screening athletes for structural abnormalities related to current or future musculoskeletal complaints, and monitoring their return to sport after a musculoskeletal injury. However, several practical and methodological aspects of US techniques should be considered when applying this technology in the elite sports context. Therefore, this narrative review aims to (1) present the principal US measures and field of applications in the context of elite sports; (2) to discuss, from a methodological perspective, the strengths and shortcomings of US imaging for the assessment of muscle and tendon properties; and (3) to provide future directions for research and application.

Key Performance Indicators Related to Strength, Endurance, Flexibility, Anthropometrics, and Swimming Performance for Competitive Aquatic Lifesaving

The aim of the study was to investigate key performance indicators for the individual pool-based disciplines of competitive lifesaving regarding strength, flexibility, sprint and endurance swimming performance, anthropometric characteristics, and technical skills specific to competitive lifesaving. Data were collected from Swiss national team members (seven males: age 19 ± 2 yrs, body mass 77 ± 11 kg, body height 177 ± 7 cm and seven females age 21 ± 5 yrs, body mass 64 ± 6 kg, body height 171 ± 4 cm) competing at the 2019 European lifesaving championships. Potential key performance indicators were assessed with race times derived from the 2019 long-course season using Spearman’s correlation coefficient. Large and significant correlations showed that sprint, i.e., 50 m freestyle performance (r ≥ 0.770), was related to race time of all pool-based disciplines, rather than endurance swimming performance. Additionally, significant correlations revealed upper body strength, i.e., bench press (r ≥ −0.644) and pull (r ≥ −0.697), and leg strength (r ≥ −0.627) as key performance indicators. Importance of the lifesaving-specific skills, anthropometric characteristics, and core strength varied between the disciplines. Flexibility was not significantly related to race times of competitive lifesaving. The present study showed that sprint swimming performance, upper body, and leg strength are particularly important for competitive lifesaving. As other physical and technical requirements varied between the pool-based disciplines, coaches may use the present key performance indicators to establish training guidelines and conditioning programs as well as prioritize skill acquisition in training to specifically prepare athletes for their main disciplines.

Internal Risk Factors for Low Back Pain in Pole Vaulters and Decathletes: A Prospective Study

Background:

Pole vaulters and decathletes frequently experience several types of injuries to their lower back, often resulting in mechanical low back pain (LBP). However, the risk factors for the occurrence of LBP in these athletes have not been defined.

Purpose:

To determine the physical factors that relate to LBP occurrence for collegiate pole vaulters and decathletes.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

We observed 31 pole vaulters and decathletes for 1 year. At the start of the observation period, isokinetic flexion and extension muscle strength of the knee and hip joints were recorded along with active and passive range of motion (ROM) and muscle tightness. Participants were then divided into 2 groups using the median value of each measurement: those below the median (low group) and those above the median (high group). The log-rank test was used to compare LBP occurrence between the low group and high group for all measurements. Multivariate regression analyses were thereafter applied using the Cox proportional hazards regression.

Results:

Log-rank tests revealed a statistically significant change in the survival curve for the occurrence of LBP in the participants with chronic LBP (P = .037), the low group for hip flexion peak torque per body weight on the non-takeoff leg (P = .047), and the low group for passive hip flexion angle on both legs (takeoff leg: P = .034; non-takeoff leg: P = .023). In addition, log-rank tests revealed a statistically significant change in the survival curve for the occurrence of LBP in the low group for passive hip extension angle on the takeoff leg only for the participants without chronic LBP (P = .014).

Conclusion:

It may be necessary to acquire sufficient ROM and hip flexion to prevent LBP occurrence in pole vaulters and decathletes.