Cervical range of motion, cervical and shoulder strength in senior versus age-grade Rugby Union International front-row forwards

Normative values for internal and external glenohumeral rotation strength in rugby players: A systematic review with meta-analysis

This systematic review aims to provide normative values for internal and external glenohumeral rotation strength in rugby players. From the inception to March 2021, the search strategy was (strength OR torque) AND shoulder AND rugby using PubMed, Scopus, Web of Science, and SPORTDiscus databases, with no language restrictions. This systematic review includes 15 articles involving 573 rugby players and presenting internal or external glenohumeral rotation strength values. Two main methods are used to assess glenohumeral rotation strength in rugby players: isokinetic and isometric methods; in the isometric method, the upper arm is abducted at either 0° or 90°. Owing to differences in isokinetic procedures and a lack of studies assessing isometric strength when the upper arm is in a neutral position, normative internal or external glenohumeral rotation strength values are only provided for isometric contractions when the upper arm is abducted at 90° based on 311 shoulders of 163 male rugby union players, with 2.04 ± 0.15 N.kg-1 and 2.11 ± 0.13 N.kg-1 for internal and external glenohumeral rotation strength, respectively. These findings may help strength and conditioning coaches and physical therapists, provide objective evidence when deciding whether or not rugby union players should return to sport.

A Profile of Isometric Cervical Strength in Elite Professional Male Rugby Players

OBJECTIVES: To (1) provide position-specific normative data for isometric cervical muscle strength and endurance in professional, male rugby players and (2) assess the relationship between age, height, weight, and playing position with cervical muscle strength and endurance. DESIGN: Cross-sectional study. METHODS: Professional rugby players completed peak isometric cervical strength testing followed by a test of cervical muscle endurance. Descriptive statistics for continuous variables with strength normalized to body weight were performed. Multiple linear regression was used to estimate associations between strength measurements. RESULTS: In total, 136 players participated including front-row forwards (27%), other forwards (28%), and backs (45%). Front-row forwards had significantly greater peak isometric cervical muscle strength than other position groups, with backs having the lowest strength. Extension produced the highest force for all 3 position groups (429 N ± 104 N), whereas flexion produced the least (275 N ± 65 N). Age was associated with increased isometric cervical muscle strength. There was a statistically significant relationship between peak flexion strength and flexion endurance (P = .003). The average time for the endurance tests were 55.7 (±17.1) seconds and 52.9 (±20.1) seconds for extension and flexion, respectively. Other forwards had lower cervical extension muscle endurance than backs and front-row forwards. CONCLUSIONS: Normative values for peak and endurance isometric strength in professional rugby players illustrate significant differences between playing position. Consider age, body weight, and intraindividual variability when interpreting cervical strength and endurance results. J Orthop Sports Phys Ther 2024;54(3):1-8. Epub 29 January 2024. doi:10.2519/jospt.2024.11830.

Neck Strength Assessment Offers No Clinical Value in Predicting Concussion in Male Professional Rugby Players: A Prospective Cohort Study

OBJECTIVE: To determine if neck muscle strength and endurance are associated with concussion injuries in professional, male rugby players. Playing position, history of previous concussion, and age were also considered. DESIGN: Prospective cohort study METHODS: One hundred thirty-six male, professional rugby players completed neck strength testing that comprised a peak isometric test, an endurance test, and a concussion screening questionnaire. Electronic medical records were analyzed for head injury data. RESULTS: Out of 136 players (mean age, 25.3 ± 3.4 years; height, 186 ± 7 cm; weight, 103 ± 13.2 kg), 40 players suffered from 51 concussions in the 2017/18 playing season. A history of concussion was reported by 65% of the cohort. Multiple logistic regression analysis found that peak isometric flexion strength was not associated with concussion risk. Increased peak isometric extension strength was associated with significantly greater odds of sustaining a concussion (odds ratio [OR] = 1.01; 95% CI: 1.00, 1.01, does not include 1; P = .04) that is likely too small to be clinically relevant. Players with a self-reported history of concussion had over 2 times greater odds of sustaining a concussion (OR = 2.25; 95% CI: 0.73, 6.22). More than 2 concussions in the past 12 months was associated with almost tenfold greater odds of concussion (OR = 9.51; 95% CI: 1.66, 54.55). Age, playing position, and neck muscle endurance were not associated with concussion. CONCLUSION: The strongest predictor of concussion injury was previous concussion. Players who sustained concussions in season had similar neck muscle strength to players who had not sustained a concussion. J Orthop Sports Phys Ther 2023;53(5):1-7. Epub: 5 April 2023. doi:10.2519/jospt.2023.11723.

Reliability of Repeated Isometric Neck Strength in Rugby Union Players Using a Load Cell Device

Concussion is the most common injury in professional Rugby Union (RU) players, with increasing incidence and severity each year. Strengthening the neck is an intervention used to decrease concussion incidence and severity, which can only be proven effective if strength neck measures are reliable. We conducted a repeated-measures reliability study with 23 male RU players. Neck strength was assessed seated in a ‘make’ test fashion in flexion, extension, and bilateral-side flexion. Flexion-to-extension and left-to-right side ratios were also computed. Three testing sessions were undertaken over three consecutive weeks. Intrasession and intersession reliabilities were assessed using typical errors, coefficient of variations (CV), and intraclass correlation coefficients (ICC). Intrasession reliability demonstrated good-to-excellent relative (ICC > 0.75) and good absolute (CV ≤ 20%) reliability in all directions (ICC = 0.86−0.95, CV = 6.4−8.8%), whereas intersession reliability showed fair relative (ICC: 0.40 to 0.75) and acceptable absolute (CV ≤ 20%) reliability for mean and maximal values (ICC = 0.51−0.69, CV = 14.5−19.8%). Intrasession reliability for flexion-to-extension ratio was good (relative, ICC = 0.86) and acceptable (absolute, CV = 11.5%) and was fair (relative, ICC = 0.75) and acceptable (absolute, CV = 11.5%) for left-to-right ratio. Intersession ratios from mean and maximal values were fair (relative, ICC = 0.52−0.55) but not always acceptable (absolute, CV = 16.8−24%). Assessing isometric neck strength with a head harness and a cable with a load cell device seated in semi-professional RU players is feasible and demonstrates good-to-excellent intrasession and fair intersession reliability. We provide data from RU players to inform practice and assist standardisation of testing methods.

Neck strength in Rugby Union players: a systematic review of the literature

The incidence and severity of concussion injuries are increasing every year. Scientific evidence indicates that neck strength and girth could play a role in preventing head and neck injuries, or at least mitigating their severity. We aimed to examine the scientific literature addressing neck strength in Rugby Union with a focus on the potential role of neck strength on injury incidence, neck assessment protocols, neck strength measures, and neck strengthening exercises.We conducted a systematic search of the literature in January 2021 to locate published peer-reviewed articles from PubMed, SPORTDiscus^TM, Web of Science®, and Scopus® e-databases. Overall, senior elite male players were stronger than younger-aged players. Forwards were stronger in extension than any other directions assessed, and were generally stronger and possessed larger necks and greater cross-sectional areas when compared to backs. Implementation of isometric exercise routines in professional players was reported to improve neck strength in all directions. There were no studies evaluating the incidence of concussion and neck strength or neck strengthening strategies in Rugby Union. Strengthening the neck continues to be one of the targeted modifiable risk factors with respect to limiting the severity and temporal effects of head injuries in Rugby Union, despite limited evidence regarding direct associations between neck strength and concussion.

Eight Weeks of Self-Resisted Neck Strength Training Improves Neck Strength in Age-Grade Rugby Union Players: A Pilot Randomized Controlled Trial

BACKGROUND

Greater neck strength is associated with fewer head and neck injuries. Neck-strengthening programs are commonly burdensome, requiring specialist equipment or significant time commitment, which are barriers to implementation.

HYPOTHESIS

Completing a neck-strengthening program will increase isometric neck strength in age-group rugby players.

STUDY DESIGN

A pilot randomized controlled exercise intervention study.

LEVEL OF EVIDENCE

Level 2.

METHODS

Twenty-eight U18 (under 18) male regional age-group rugby union players were randomized (intervention n =15/control n = 13). An 8-week exercise program was supervised during preseason at the regional training center. Control players continued their "normal practice," which did not include neck-specific strengthening exercises. The 3-times weekly trainer-led intervention program involved a series of 15-second self-resisted contractions, where players pushed maximally against their own head, in forward, backward, left, and right directions.

OUTCOME MEASURE

Peak isometric neck strength (force N) into neck flexion, extension, and left and right side flexion was measured using a handheld dynamometer.

RESULTS

Postintervention between-group mean differences (MDs) in isometric neck strength change were adjusted for baseline strength and favored the intervention for total neck strength (effect size [ES] = 1.2, MD ± 95% CI = 155.9 ± 101.9 N, P = 0.004) and for neck strength into extension (ES = 1.0, MD ± 95% CI = 59.9 ± 45.4 N, P = 0.01), left side flexion (ES = 0.7, MD ± 95% CI = 27.5 ± 26.9 N, P = 0.05), and right side flexion (ES = 1.3, MD ± 95% CI = 50.5 ± 34.4 N, P = 0.006).

CONCLUSION

This resource-efficient neck-strengthening program has few barriers to implementation and provides a clear benefit in U18 players' neck strength. While the present study focused on adolescent rugby players, the program may be appropriate across all sports where head and neck injuries are of concern and resources are limited.

CLINICAL RELEVANCE

Greater neck strength is associated with fewer head and neck injuries, including concussion. Performing this neck exercise program independently, or as part of a whole-body program like Activate, an interactive guide for players and coaches, could contribute to lower sports-related head and neck injuries.

Normative values of cervical range of motion for both children and adults: A systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To synthesize studies reporting normative values of active cervical range of motion (ROM) in healthy children and adults.

SUMMARY OF BACKGROUND DATA

Evaluating active cervical ROM is part of routine assessment of patients with neck pain. Interpretation of outcomes necessitates having normative data per age category. Currently available normative values differ across studies, perhaps due to (the measurement properties of) the devices used.

METHODS

A systematic review according to PRISMA guidelines was conducted. Electronic searches included EMBASE, MEDLINE, Web of Science, Cochrane, CINAHL and Google Scholar databases from inception to August 2018. Included studies had to involve healthy subjects in which active cervical ROM was assessed or when determining normative values was the aim of the study. Methodological quality of the included studies was assessed using an adapted version of the QUADAS. A mean value was re-calculated for the total group in case data were presented per gender per age-category only. When possible, data were pooled.

RESULTS

From 2151 unique hits, 217 articles were selected for full text assessment, after which 162 articles were excluded. Data were extracted from 55 articles using 16 different measurement devices. Twenty-five studies were rated as being of "low risk of bias". Only data from studies evaluating the CROM device and Zebris could be pooled.

CONCLUSIONS

This systematic review revealed that although a large number of studies assessed normative data for active cervical ROM, the methodological quality of most studies was low and the heterogeneity between studies was high. Only the normative data for active cervical ROM using the CROM device seems to be useful. Overall, reference values for measuring active cervical ROM is unclear for most measurement devices. Normative values of cervical range of motion for both children and adults: a systematic review.

Assessment of Interrater and Intrarater Reliability of Cervical Range of Motion (CROM) Goniometer

Purpose

The current study was designed to assess interrater and intrarater validity of cervical range of motion measurements performed with a CROM goniometer. Material and Methods. The study involved 95 healthy university students (31 males and 64 females) aged 20-24 years. Two examiners performed measurements of cervical range of motion using a CROM goniometer. The same subjects were examined again after two weeks, in the same conditions. The results acquired by one rater during the first and the second examination were compared for reproducibility, while the results obtained by the two examiners were compared to assess validity and reliability of the tool. Cronbach's alpha was applied to determine intrarater reliability, and the values of correlations were used to assess the interrater agreement.

Results

Analysis of the results showed both intrarater and interrater agreement in all the measures of cervical range of motion. The highest intrarater and interrater concordance was observed in the measure of extension. Intrarater agreement for Examiner 1 was reflected by Cronbach's alpha = 0.85, and for Examiner 2 by Cronbach's alpha = 0.89. As for the interrater agreement in the measure of extension, the value of correlation in both the first and the second measurement amounted to r = 0.89.

Conclusions

Measurements performed with the CROM goniometer show interrater and intrarater agreement in assessments of cervical range of motion. The CROM goniometer can be recommended for use in daily clinical practice.

Cervical range of motion in school age rugby union players: A cross sectional study

OBJECTIVES

Provide normative values for cervical range of motion and describe trends in school age rugby union players.

DESIGN

Cross-sectional study.

SETTING

National 3 level club.

PARTICIPANTS

59 school age rugby union players across under 8 (n = 8), under 9 (n = 9), under 10 (n = 15), under 13 (n = 13) and under 15 (n = 15) categories.

MAIN OUTCOME MEASURES

Cervical range of motion using a cervical range of motion device (CROM) to determine values for active range of motion.

RESULTS

This study established mean ranges of motion for each age group. Pooled mean ranges with standard deviations for each direction were, flexion 66° (±11), extension 73° (±17), left rotation 69° (±9), right rotation 74° (±10), left lateral flexion 53° (±10) and right lateral flexion 49° (±12). No statistically significant differences were observed between the age groups, however, downward trends in lateral flexion were observed as age increased. School age rugby players had greater range of motion than senior playing counterparts.

CONCLUSIONS

No statistically significant differences in ranges of motion were observed between the age groups of under 8 through to under 15. However, downward trends in some ranges of motion highlight the need for age specific monitoring for potential adaptations to continued playing and comparison to age matched non-rugby players. Inclusion of other risk factors such as head re-positioning sense should also be evaluated to help guide injury risk reduction strategies.