Reliability and validity of measurements of cervical retraction strength obtained with a hand-held dynamometer

Evolving Dynamics of Neck Muscle Activation Patterns in Dental Students: A Longitudinal Study

Cervical pain has been linked to increased motor unit activity, potentially associated with the initiation and progression of chronic neck pain. Therefore, this study aimed to compare the time-course changes in cervical superficial muscle activation patterns among dental students with and without neck pain throughout their initial semester of clinical training. We used an online Nordic Musculoskeletal Questionnaire for group allocation between neck pain (NP) (n = 21) and control group (CG) (n = 23). Surface electromyography (sEMG) of the sternocleidomastoid and upper bilateral trapezius was recorded before starting their clinical practice and after their first semester while performing a cranio-cervical flexion test (CCFT) in five increasing levels between 22 mmHg and 30 mmHg. After the first semester, both the CG (p < 0.001) and NP (p = 0.038) groups showed decreased sternocleidomastoid activation. The NP group exhibited a concomitant increase in upper trapezius coactivation (p < 0.001), whereas the muscle activation pattern in asymptomatic students remained unchanged (p = 0.980). During the first semester of clinical training, dental students exhibited decreased superficial flexor activity, but those with neck pain had increased co-contraction of the upper trapezius, likely to stabilize the painful segment. This altered activation pattern could be associated with further dysfunction and symptoms, potentially contributing to chronicity.

Measures of neck muscle strength and their measurement properties in adults with chronic neck pain-a systematic review

BACKGROUND

Measurement of neck muscle strength is common during the assessment of people with chronic neck pain (CNP). This systematic review evaluates the measurement properties (reliability, validity, and responsiveness) of neck muscle strength measures in people with CNP.

DATABASES AND DATA TREATMENT

This systematic review followed a PROSPERO registered protocol (CRD42021233290). Electronic databases MEDLINE (OVID interface), CINAHL, SPORTDiscuss via (EBSCO interface), EMBASE (OVID interface), and Web of Science were searched from inception to 21 June 2021. Screening, data extraction, and quality assessment (Consensus-based Standards for the selection of Health Measurement Instruments (COSMIN) checklist) were conducted independently by two reviewers. The overall strength of evidence was evaluated using the modified Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

From 794 records, nine articles were included in this review which concerned six different neck strength outcome measures. All studies evaluated reliability and one evaluated construct validity. The reliability of neck strength measures ranged from good to excellent. However, the risk of bias was rated as doubtful/inadequate for all except one study and the overall certainty of evidence was rated low/very low for all measures except for the measurement error of a handheld dynamometer.

CONCLUSION

A multitude of measures are used to evaluate neck muscle strength in people with CNP, but their measurement properties have not been fully established. Further methodologically rigorous research is required to increase the overall quality of evidence.

Neck Strength Evaluated With Fixed and Portable Dynamometers in Asymptomatic Individuals: Correlation, Concurrent Validity, and Agreement

OBJECTIVE

The purpose of this study was to assess the correlation, concurrent validity, and agreement between the isometric cervical force measurements obtained with fixed and portable dynamometers in asymptomatic individuals.

METHODS

Fifty asymptomatic individuals performed 3 maximal isometric contractions for flexion, extension, and lateral flexion of the cervical spine using fixed and portable dynamometers. The correlation and concurrent validity for the measurements of the portable and fixed dynamometers were analyzed using Spearman's correlation coefficient and the intraclass correlation coefficient (ICC), respectively. The agreement between the force values of the portable and fixed dynamometers was measured using the Bland-Altman method.

RESULTS

Isometric cervical force measurements obtained with the fixed dynamometer and portable dynamometer showed a moderately to highly significant correlation for flexion (r_s = 0.74), extension (r_s = 0.82), right lateral flexion (r_s = 0.74), and left lateral flexion (r_s = 0.68). The concurrent validity was moderate to good for all measurements (ICC_2,3 = 0.67-0.80). The fixed and portable dynamometers did not agree, with a significant mean difference between the methods of 2.8 kgf (95% confidence interval [CI], 2.1-3.4 kgf) for cervical flexion, 5.3 kgf (95% CI, 4.2-6.4 kgf) for extension, and 9.1 kgf (95% CI, 0.4-2.1 kgf) for left lateral flexion. The limits of agreement were broad for all movements, with errors that varied between 61% and 77% of the mean force obtained with the fixed dynamometer.

CONCLUSION

The neck strength measurements obtained with the fixed and portable dynamometers demonstrated high to moderate correlation and had moderate to good comparability for asymptomatic participants. However, they did not agree in that the 2 methods did not provide equivalent measurements, and, therefore, based on these findings, the same equipment should always be used when reassessing an individual.

Reliability and difference in neck extensor muscles strength measured by a portable dynamometer in individuals with and without chronic neck pain

OBJECTIVE

There are limited reports about the reliability of measuring neck extensor muscle strength using a portable dynamometer in neck pain patients. The aims of the current study were 1) to investigate intra- and inter-rater reliability of neck extensor isometric strength measurement using a portable dynamometer in patients with chronic nonspecific neck pain (CNSNP) and 2) to compare neck extensor isometric strength in participants with and without CNSNP.

METHODS

Guidelines for Reporting Reliability and Agreement Studies (GRRAS) were followed. Two examiners received a 15-minute training before enrollment. Inter-rater reliability was assessed with a 10-minute interval between measurements, and intra-rater reliability was assessed with a 10-day interval. Three trials were assessed and examiners were blind to the strength values (in Newtons) from other sessions of 20 individuals with CNSNP (mean±SD= 37.9 ± 9.8y; Neck Disability Index 29.2 ± 7.4%) and 20 individuals with other musculoskeletal disorders (mean ± SD = 32.8 ± 46.2y).

RESULTS

Intra-rater reliability was excellent with intraclass correlation coefficient (ICC)(3,1) of 0.95 (CI:0.90-0.97) and inter-rater reliability was good to excellent with ICC(2,1) of 0.88 (CI:0.77-0.94) in CNSNP. No significant difference of neck extensor strength was found between CNSNP (93.27N±31.94) and Individuals without CNSNP (111.43N±40.11) (p > 0.05).

CONCLUSION

A portable dynamometer is a reliable tool for measuring maximal isometric neck extension strength in individuals with CNSNP. Slightly but no significant differences of neck extensor strength values between individuals with and without CNSNP. Future studies are needed to assess the generalizability of the findings in patients with other muscle deconditioning.

Magnitude, validity and responsiveness of dynamometer measured neck retraction strength in patients referred with neck pain to out-patient physical therapy

[Purpose] The magnitude, validity, and reliability of dynamometer measures of neck retraction strength have been reported but not for individuals referred with neck complaints to physical therapy. The purpose of this study, therefore, was to describe neck retraction strength and its responsiveness and validity as a correlate of neck pain and disability among patients referred for physical therapy. [Participant and Methods] Twenty-six consecutive patients referred with neck pain participated. Their neck retraction strength was measured with a handheld dynamometer using a standardized procedure. Neck pain and disability were quantified using a numeric pain rating scale and the Neck Disability Index, respectively. [Results] Measurements of neck retraction strength increased significantly over the episode of care from 76.5 N to 119.5 N (standardized response mean=1.57 N). The correlation of retraction strength with neck pain was significant (r_s=−0.550); however, the correlation between retraction strength and Neck Disability Index scores was not significant (r_s=0.155). [Conclusion] Neck retraction strength measured with a hand-held dynamometer was informative and responsive for patients treated with neck pain. Retraction strength was correlated significantly with neck pain but not neck disability. This apparent inconsistency warrants further investigation.

An isometric neck strengthening program does not improve neck strength in elite women's football-code athletes: A randomised controlled trial

OBJECTIVES

The purpose of this study was to investigate the effectiveness of an isometric neck strengthening program to improve isometric neck strength in elite women's football-code athletes.

DESIGN

Randomised controlled trial.

METHODS

Elite female soccer (n = 10) and Australian football (n = 30) players were randomised into either a control (n = 20) or experimental (n = 20) group for a 12-week intervention study during their respective seasons. While both groups undertook their prescribed strength and conditioning programs, the experimental group also performed isometric neck strengthening exercises three times per week prior to training. Isometric neck strength of the extensors, flexors, lateral flexors, and rotators were assessed pre, mid (Week 7), and post (Week 13) intervention with a hand-held dynamometer during early to mid-competition season. A mixed design analysis of variance was performed for statistical analysis.

RESULTS

No significant group-by-time interactions in isometric neck strength were observed. All strength variables displayed a significant change over time throughout the 12-week period (p < 0.05). No significant between group differences in isometric neck strength variables were observed except for lateral left flexion (F(1, 38) =5.064, p = 0.030, η²_p = 0.117).

CONCLUSIONS

The addition of isometric neck strengthening exercises did not improve neck strength beyond a standard strength and conditioning program for elite women's football-code athletes. While this specific program may not improve neck strength in elite women's football-code athletes, further investigation is needed to determine whether sport-specific neck strength exercises may improve neck strength or if lower-level competition athletes may still benefit from an isometric neck strengthening program.

The concurrent validity and intrarater reliability of a hand-held dynamometer for the assessment of neck strength in semi-professional rugby union players

OBJECTIVES

The main objective of this study was to determine the concurrent validity between a hand-held (HHD) and mounted hand-held dynamometer (MHHD) for assessing isometric neck strength.

DESIGN

Observational design.

SETTING

Semiprofessional rugby club.

PARTICIPANTS

Nineteen semi-professional rugby players (age = 26 ± 5 years, stature = 186.5 ± 6.5 cm, body mass = 98.7 ± 12.8 kg).

MAIN OUTCOME MEASURES

Concurrent validity (limits of agreement, correlation) between HHD and MHHD, the intrarater reliability (intra-class correlation, ICC) and comparison between playing positions.

RESULTS

Absolute peak and mean peak force were systematically lower when using the HHD compared to MHHD, with the mean bias ranging from -1.8 to -3.8 kgf (P < 0.05). Differences were not evident for flexion when applying the correction equations (-0.5 to 2.1 kgf, P > 0.05) but remained for extension. Correlations between methods were large-to-very large; the ICCs for both methods were good (ICC = 0.72-0.89), with no difference between positions (P < 0.05).

CONCLUSION

The concurrent validity of HHD was considered acceptable when compared to the MHHD and the correction equation applied. Both methods are reliable and useful for assessing neck strength in rugby players, though, caution is needed when determining strength during neck extension.

Reliability of Hand-Held Dynamometer for assessing Isometric Lumbar Muscles Strength in Asymptomatic Healthy Population

Objective:

To determine intra-rater and inter-rater reliability of hand-held dynamometer for assessing isometric lumbar muscle strength in asymptomatic healthy population.

Methods:

It was a cross-sectional study conducted at the department of physiotherapy, University of Lahore Teaching Hospital, Lahore, Pakistan, from July 2020 to August 2020 through non probability-purposive sampling technique. Thirty healthy subjects were tested at thirty-degree lumbar flexion and zero-degree lumbar extension positions. Two raters assessed isometric strength of lumbar flexor and extensor muscles, by a hand-held dynamometer. Strength was measured and recorded by each of the two raters and re-assessed after a week. Correlation and pairwise comparison were done between readings. ICC values were calculated for the assessment of isometric lumbar muscle strength using handheld dynamometer.

Results:

A total of 30 healthy subjects had participated with mean age of 22.84±1.21 years, height 174.33±6.83 cm, weight 68.58±5.08 kg and BMI 22.52±0.35. Findings showed an excellent intra-rater (ICC 2, k = 0.95 to 0.97) and inter-rater (ICC 2, k = 0.94 to 0.95) reliability.

Conclusions:

Hand held dynamometer demonstrated an excellent intra- and inter-rater reliability for assessment of isometric lumbar muscles strength of healthy subject at clinical setting as it is simple to use, portable and cost-effective for the precise measurement of lumbar muscles strength.

Reliability and Validity of Clinical Tests for Measuring Strength or Endurance of Cervical Muscles: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the reliability and validity of clinical tests for measuring cervical muscle strength or endurance in participants with and without neck pain.

DATA SOURCE

Systematic review and meta-analysis on reliability and validity. Literature search was conducted on January 28, 2020, using 5 databases: MEDLINE, Cumulative Index to Nursing and Allied Health, EMBASE, SPORTDiscus, and Scopus.

STUDY SELECTION

We included studies that investigated the reliability or validity of clinical tests for measuring cervical muscle strength or endurance in participants with nonspecific chronic neck pain, with or without irradiation, or healthy participants. We included only those that were viable for daily practice and of low cost.

DATA EXTRACTION

Data were extracted as follows: (1) author and year of publication, (2) demographic values and health condition, (3) reported clinical tests, (4) inclusion and exclusion criteria, (5) description of test, (6) interrater reliability, and (7) intrarater reliability. For validity studies we also extracted the (8) reference method and (9) validity estimates.

DATA SYNTHESIS

Methodological quality was assessed with the Quality Appraisal of Diagnostic Reliability and the Guidelines for Reporting Reliability and Agreement Studies. Data on reliability and validity were extracted from included articles and then analyzed.

RESULTS

Thirty-one studies were included. Cervical flexor and extensor endurance test, craniocervical flexion test (CCFT), AND cervical muscle strength using a handheld dynamometer (HHD) showed moderate to good intra- and interrater reliability (intraclass correlation coefficients ranging from 0.64-0.90). Concurrent validity was measured by only 2 studies, which do not provide adequate evidence for a recommendation.

CONCLUSIONS

The cervical flexor and extensor endurance tests, CCFT, and HHD for measuring cervical strength presented an acceptable interrater and intrarater reliability.

Virtual immersive sensorimotor training (VIST) in collegiate soccer athletes: A quasi-experimental study

A burgeoning area of innovation in sports is the use of extended realities to provide athletes with novel training environments. Evidence has demonstrated that virtual environments can be useful therapeutic tools with demonstrated positive outcomes. The purpose of this pilot investigation was to determine the effects of virtual immersive sensorimotor training intervention by quantifying 1) the training effect measured via change in performance pre-to post-intervention on the virtual reality exercises, 2) the difference in the in clinical measures of functional sensorimotor control, 3) the injury incidence rate, and 4) on-field performance during soccer competitions. Statistical analyses were used to describe differences between an experimental and a control group. Participants were recruited from the men and women's soccer teams at two universities in the United States. Participants at one university were in the experimental group (n = 78) and received virtual immersive sensorimotor training, consisting of nine novel exercises in headset virtual reality, twice each week for six weeks. Participants at the second university were in the control group (n = 52). The virtual exercises were developed with reference to the rehabilitative principles of neuroplasticity to train various neurologic processes, contributing to overall sensorimotor control. This includes vestibular, visual and oculomotor activities, cervical neuromotor control training, movement coordination, and postural/balance exercises. The results indicate significant positive training effects pre-to post-intervention in seven of the nine training exercises (p ≤ 0.005) and improvement in clinical tests of cervical neuromotor control, balance, and inspection time (p ≤ 0.009) in the experimental group compared to the control. One of the virtual training exercises was positively associated with on-field performance (p = 0.022). No differences in injury rate or overall on-field performance metrics between the experimental and control were detected. This research study provides evidence of training and positive transfer from virtual to real-world environments, supporting the use of these novel virtual exercises to improve measures of sensorimotor control in healthy soccer athletes.

Forward flexed posture: reliability and determinants of tragus-to-wall measurement

INTRODUCTION

Forward flexed posture is an impairment in body structure commonly seen among older adults and those with pathologies such as ankylosing spondylitis and osteoporosis. Accurate measurement of forward flexed posture is important as it is related to pain, mobility limitations, and falls. Our purpose was to examine the reliability and determinants of forward flexed posture as indicated by tragus-to-wall (TTW) distance.

METHODS

Twenty healthy younger and 20 healthy older adults were included in this secondary analysis of data from a neck strength study. Measurements included the linear distance of TTW standing naturally and with neck retraction, age, gender, body mass index (BMI), and neck retraction strength. Measurements were performed initially by 2 investigators and by the primary investigator 1 week later. Intraclass correlation coefficients (ICCs) (model 3,1) described relative reliability and Bland-Altman plots characterized absolute reliability. A mixed general linear model examined the determinants for TTW distance.

RESULTS

Good inter-rater (ICC = 0.811-0.878) and test-retest reliability (ICC = 0.853-0.862) were found in both positions. Bland-Altman plots showed that absolute limits of agreement ranged from - 1.9 to +3.8 cm for inter-rater reliability and -2.4 to +2.6 cm for test-retest reliability. Analysis of TTW determinants demonstrated significant differences between neck positions, dichotomous age groups, and BMI groups (p ≤ 0.001). There was no significant difference based on neck strength.

CONCLUSIONS

Our results indicate that TTW distance, measured using a standardized procedure, is a reliable method of quantifying forward flexed posture. TTW distance is greater in relaxed standing, older individuals, and those with greater BMI.