Pupillometric parameters of alertness during unpredictable but not predictable smooth pursuit neck torsion test are altered in patients with neck pain disorders: a cross-sectional study.

Despite commonly investigated predictable smooth-pursuit neck-torsion tasks (SPNT) in neck pain patients, unpredictable conditions have been seldom investigated but are indicative of preserved oculomotor functions during neck torsion. Although not previously studied, some speculations about compensatory cognitive mechanisms such as increased phasic alertness during unpredictable tasks were suggested. The aim of this study was to investigate eye movement accuracy and pupillometric responses during predictable and unpredictable SPNT test in neck pain patients and asymptomatic controls. Eye movements (gain and SPNT-difference) and pupillometry indicative of tonic (average and relative pupil diameter) and phasic (index of cognitive activity-ICA) alertness were measured in 28 idiopathic neck pain patients and 30 asymptomatic individuals using infrared video-oculography during predictable and unpredictable SPNT test. Gain in unpredictable SPNT test was lower as compared to predictable tasks and presented with similar levels in neutral and neck torsion positions, but not in the predictable SPNT test. ICA was lower during neutral position in all tasks in patients as compared to control group but increased during neck torsion positions in unpredictable tasks. Relative pupil diameters presented with no differences between the groups or neck positions, but the opposite was observed for average pupil diameter. Higher ICA indicates an increase in phasic alertness in neck pain patients despite no alterations in oculomotor control during SPNT test. This is the first study to indicate cognitive deficits in oculomotor task in neck pain patients. The latter could negatively affect other tasks where additional cognitive resources must be involved.

How well can we detect cervical driven sensorimotor dysfunction in concussion patients? An observational study comparing patients with idiopathic neck pain, whiplash associated disorders and concussion.

BACKGROUND: Patients with mild traumatic brain injury (mTBI) suffer from sensorimotor impairments. Evidence is emerging that cervical spine plays an important role in mTBI, but it is not known how cervicocephalic kinaesthetic sensibility measured during dynamic unpredictable head movements and measures of position sense, cervical induced postural balance and eye movement control differ between mTBI, whiplash associated disorders (WAD) patients, idiopathic neck pain patients and healthy controls. RESEARCH QUESTION: Are cervical sensorimotor deficits present in mTBI patients and do they differ from sensorimotor deficits found in traumatic and nontraumatic neck pain patients and whether they differ from healthy controls. METHODS: Twenty idiopathic neck pain patients, 18 WAD, 17 mTBI and 20 healthy controls were enroled in the study. Frequency and velocity of centre of pressure movements were measured during parallel stance in the neutral and neck torsion positions, gain and smooth pursuit neck torsion difference of eye movements during smooth pursuit neck torsion test (SPNTT) and cervicocephalic kinaesthesia using Butterfly and head-to-neutral relocation test. RESULTS: Statistically significant differences in postural balance, both tests of cervicocephalic kinaesthesia and SPNTT were observed between healthy controls and all patient groups. No differences were observed between patient groups for SPNTT, Butterfly and head-to-neutral relocation test, but differences were present in postural balance between mTBI and both groups of patients with neck pain disorders. Differences were found in the ML direction for mTBI, but not differences were found for AP direction. SIGNIFICANCE: Results of our study show that mTBI present with similar impairment in cervical driven sensorimotor deficits as patients with neck pain disorders, but they differ from healthy individuals. Clinical practice would benefit from identifying cervical spine related sensorimotor impairments in patients with mTBI. This could enable to design more targeted prevention and rehabilitation programs to minimise cervical spine related disorders in concussion patients.

Relationship between Cervicocephalic Kinesthetic Sensibility Measured during Dynamic Unpredictable Head Movements and Eye Movement Control or Postural Balance in Neck Pain Patients.

Cervical afferent input is believed to affect postural balance and oculomotor control in neck pain patients, but its relationship to cervicocephalic kinesthesia, describing movement sense, has not yet been studied. The aim of this study was to analyze the relationship of two aspects of cervicocephalic kinesthesia to postural balance and oculomotor control in neck torsion positions. Forty-three idiopathic neck pain patients referred from orthopedic outpatient clinics and forty-two asymptomatic controls were enrolled in the study. A force plate was used to measure center-of-pressure movements during parallel stances under neutral and neck torsion maneuvers. Video-oculography was used to assess eye movements during smooth pursuit neck torsion test (SPNTT), while kinesthetic awareness was measured using the Butterfly test and head-to-neutral relocation test. Multiple regression was used to describe relationships between tests. Body sway in the anterior-posterior direction was related to Butterfly parameters but less to the head-to-neutral test. A medium relationship between Butterfly parameters and gain during SPNTT, with less SPNT-difference, was observed, but not for the head-to-neutral test. It can be concluded that specific aspect of neck kinesthetic functions (i.e., movement sense) importantly contributes towards oculomotor and balance control, which is more evident under neck torsion positions in neck pain patients, but is less pronounced in asymptomatic individuals.

Video-oculographic measures of eye movement control in the smooth pursuit neck torsion test can classify idiopathic neck pain patients from healthy individuals: A datamining based diagnostic accuracy study.

BACKGROUND: Idiopathic neck pain patients frequently experience oculomotor disfunctions with deficits in eye movement control between neutral and neck torsion position (SPNT test) being commonly investigated in clinical and research settings. OBJECTIVES: The aim of the study was to determine accuracy of SPNT test in classifying idiopathic neck pain patients. DESIGN: a datamining based diagnostic accuracy study. METHODS: The study was conducted on a referred sample of 38 chronic neck pain patients from orthopaedic outpatient clinic and 40 healthy controls. Video-oculography was used to study gain and SPNTdiff during SPNT test under three target movement velocities and amplitudes and two different angles of neck torsion. A Naïve Bayesian predictive model was used to classify neck pain patients based on gain or SPNTdiff. RESULTS: Gain during two target movement profiles at velocities of 30°s-1 and amplitudes of 30° and 40° under 45° of neck torsion presented with highest area under the curve (0.837), specificity (92%), sensitivity (94%), highest true positive and lowest false negative predicted value. Highest area under the curve (0.760), specificity (50%), sensitivity (71%), highest true positive and lowest false negative values were observed for SPNTdiff at velocities of 30°s-1 and amplitude of 30° applying 45° of neck torsion. CONCLUSION: SPNT test provides useful diagnostic tool for classifying neck pain patients when using single or combination of two target movement profiles. Neck torsion of 45° as opposed to 30° should be used during SPNT test when investigating patients with neck pain disorders.

Is Altered Oculomotor Control during Smooth Pursuit Neck Torsion Test Related to Subjective Visual Complaints in Patients with Neck Pain Disorders?

Subjective visual complaints are commonly reported in patients with neck pain, but their relation to objectively measured oculomotor functions during smooth pursuit neck torsion tests (SPNTs) has not yet been investigated. The aim of the study was to analyse classification accuracy of visual symptom intensity and frequency based on SPNT results. Forty-three patients with neck pain were referred by orthopaedic outpatient clinics where they were required to fill out 16-item proformas of visual complaints. Infrared video-oculography was used to measure smooth pursuit eye movements during neutral and neck torsion positions. Parameters of gain and SPNT difference (SPNTdiff) were taken into the Naïve Bayes model as classifiers, while intensity and frequency of visual symptoms were taken as predicted class. Intensity and, to a lesser degree, frequency of visual symptoms previously associated with neck pain or focal vision disorders (computer vision syndrome) showed better classification accuracy using gain at neck torsion position, indicating cervical driven visual disturbances. Moreover, SPNTdiff presented with slightly lower classification accuracy as compared to gain at neck torsion position. Our study confirmed the relationship between cervical driven oculomotor deficits and some visual complaints (concentrating to read, words moving on page, blurred vision, difficulty judging distance, sore eyes, heavy eyes, red eyes, and eyes strain).

Oculomotor performance in patients with neck pain: Does it matter which angle of neck torsion is used in smooth pursuit eye movement test and is the agreement between angles dependent on target movement amplitude and velocity?

BACKGROUND: Neck torsion manoeuvre is thought to affect eye movement control via afferent sensory drive in neck pain disorders patients. Literature reports inconsistencies regarding the angle of neck torsion most commonly used across the studies. OBJECTIVES: The goal of this study was to determine the level of agreement in oculomotor performance between two most commonly used neck torsion angles during smooth pursuit neck torsion test (SPNT). DESIGN: A cross-sectional design was used in thirty-two neck pain patients and thirty-two healthy individuals. METHOD: Gain and SPNTdiff were measured during SPNT test at 30° and 45° of neck torsion angle, at 30°, 40° and 50° of target movement amplitudes and three different target movement velocities (20°s-1, 30°s-1 and 40°s-1) using eye tracking device. Bland-Altman plots and correlation analysis were used to study the agreement between the two angles. RESULTS: Small to medium correlations and wide bias confidence intervals suggest medium level of agreement in gain or SPNTdiff between the two neck torsion angles for chronic neck pain patients, but higher in healthy individuals. Higher agreement in gain was observed at lager target movement amplitudes and at slower target movement velocities, however this trend was not observed for SPNTdiff. CONCLUSION: Level of agreement between the two angles in SPNT test depends on the amplitude and velocity of the moving target. In cases when subjects within the same study are not able to perform 45° of neck torsion, 50° amplitude and 20°s-1 velocity of target movement are more suitable to reach higher agreement between the angles.

The influence of neck torsion and sequence of cycles on intra-trial reliability of smooth pursuit eye movement test in patients with neck pain disorders.

The sensory mismatch commonly observed in patients with neck pain disorders could alter intra-trial reliability in simple implicit smooth pursuit eye movement tasks. This could be more pronounced when neck is in torsioned position (SPNT). The aim of this study was to explore the effects of neck torsion, target movement velocity and amplitude on intra-trial reliability of smooth pursuit eye movements in patients with neck pain disorders and healthy individuals. SPNT test was evaluated in 32 chronic neck pain patients and 32 healthy controls. Ten cycles were performed using video-oculography at three different velocities (20° s-1, 30° s-1 and 40° s-1) and at three different amplitudes (30°, 40° and 50°) of target movement. Intra-trial reliability and differences between average gain and SPNT difference from the second to fifth cycle and from the sixth to ninth cycle were assessed using ICC3.1 and factorial analysis of variance, respectively. Intra-trial reliability for gain and SPNT difference at all target movement amplitudes and velocities proved to be good to excellent in both observed groups. Patients with neck pain disorders presented with a trend of inferior gain performance between the sixth and ninth cycle at 30° s-1 of target movement as compared to healthy individuals which was only evident when neck was in torsioned position. Although intra-trial reliability of smooth pursuit neck torsion test is good to excellent, the effects of learning are not as pronounced in patients with neck pain disorders.

Regular strength training and baseline fitness in overweight infantry members of Slovenian Armed Forces.

INTRODUCTION: The prevalence of overweight subjects in military cohorts increases despite the obligatory army physical fitness test (APFT) requirements and the negative consequences of possible test failure due to the increased body mass index (BMI). Studies that have examined the association of BMI with baseline fitness in the military are showing conflicting evidence. The primary aim of the study is to examine BMI effects on baseline fitness that was measured by APFT and additional functional performance tests (FT) (vertical countermovement jump with and without load, loaded prone plank, single-leg hamstring bridge test and pull-ups). Our secondary goal is to explore if regular strength training modifies the BMI effect on baseline fitness. METHODS: A cross-sectional study on a sample of 118 male infantry soldiers that have performed APFT and FT was carried out. Body mass and body height measurements were used to calculate BMI, and to categorise participants into BMI ranks. Two independent categorical variables (BMI rank and strength training) were used to evaluate their influence on dependent variables of physical performance acquired from APFT and FT. RESULTS: A significantly large size effect of BMI rank (F=1.69, p=0.037; effect size (ES)=0.15) and regular strength training (F=2.66, p=0.006; ES=0.21) on physical performance was found. It was shown that strength training had a medium ES on push-up and pull-up performance, as well as on the overall APFT score and loaded plank. CONCLUSIONS: The importance of regular strength training and normal BMI for better overall baseline fitness in infantry members was highlighted. Most importantly, it was shown that performance is not affected in overweight soldiers who are performing regular strength training in addition to their daily physical training. TRIAL REGISTRATION NUMBER: NCT03415464.

Isometric Trunk Strength Assessment of Athletes: Effects of Sex, Sport, and Low Back Pain History.

CONTEXT: The importance of isometric trunk strength (ITS) among sport science professionals is higher than its actual reported effect size on either performance or low back pain (LBP) occurrence. OBJECTIVE: To provide normative values of ITS and strength ratios, and to evaluate the effect of sex, sports discipline, and LBP status. DESIGN: Crossover study. SETTING: University research laboratory. PARTICIPANTS: Five hundred and sixty-seven elite athletes (186 females) with and without a history of LBP from different sports. MAIN OUTCOME MEASURE: Participants underwent ITS testing for trunk flexors, extensors, and lateral flexors. Normalized maximal strength (in newton meter per kilogram) and strength ratios were calculated. Differences between sex, LBP, and sport disciplines were assessed with 3-way analysis of variance (sex × LBP status × 7 sport categories) and partial eta-squared (ηp2) effect size. The predictive validity of ITS for LBP was checked with receiver operating characteristics (area under the curve). RESULTS: The authors found significant differences in extensor and flexor ITS in favor of male athletes (medium ηp2, P < .05), while sex differences in lateral flexion ITS had a low size effect (P < .05). A low size effect was also observed for the differences in strength ratios extensors/flexors (mean 1.47; 95% confidence interval, 1.45-1.50) and left flexors/right flexors (mean 0.99; 95% confidence interval, 0.98-1.01) among sexes. The sport discipline-related differences generally had a low size effect. No significant differences in ITS were found between LBP and LBP-free athletes. Only 50% to 58% of athletes (area under the curve, 0.501-0.582) were correctly classified as LBP or LBP-free using different ITS and strength ratio variables. CONCLUSIONS: ITS and strength ratios have low predictive validity for LBP history but may discriminate between sex and sport disciplines. Our data are a useful reference point for meaningful individual results interpretation when athletes are evaluated during training or rehabilitation.

Inter-Visit Reliability of Smooth Pursuit Neck Torsion Test in Patients with Chronic Neck Pain and Healthy Individuals.

Visual disturbances are commonly reported in patients with neck pain. Smooth pursuit neck torsion (SPNT) test performed in neutral position and with trunk rotated under the stationary head has been used to discriminate between those with cervical component and those without. However, no studies investigated the reliability of the SPNT-test in patients with chronic neck pain and healthy controls. The aim of this study was to assess inter-visit reliability of the SPNT-test while applying different amplitudes and velocities of target movement. Thirty-two controls and thirty-one patients were enrolled in the study. The SPNT-test was performed in neutral position and through 45° torsion positions. The test was performed at 20°/s, 30°/s and 40°/s velocities and at 30°, 40° and 50° amplitudes of cyclic sinusoidal target movements. Interclass correlation coefficient and smallest detectable change were calculated for parameters of gain and SPNT-differences. In patients, moderate to good reliability was observed for gain at 40° and 50° amplitudes and for 20°/s and 30°/s velocities, while moderate to excellent reliability for gain was observed in controls. Both groups presented with moderate to good reliability for SPNT-difference. Our findings imply that amplitudes of 40° and 50° and velocities of 20°/s and 30°/s are the most reliable and should be applied in future studies assessing oculomotor functions during the SPNT test.

Postural balance and oculomotor control are influenced by neck kinaesthetic functions in elite ice hockey players.

BACKGROUND: Research indicates that neck kinaesthetic awareness plays an important role in oculomotor and balance control, however the relationship has not been studied in athletes. As performance in ice hockey demands visual perception acuity during skating, while constantly shifting between unilateral and bilateral stances in sports specific posture more in-depth relationship should be studied. RESEARCH QUESTION: What is the relationship between neck kinaesthetic awareness, postural balance and eye movement control in professional ice hockey players and non-trained individuals? METHODS: In this observational study, centre-of-pressure was measured using force plate in twenty-eight hockey players and thirty non-trained participants during different stances in eyes-opened and eyes-closed conditions. Butterfly test and Head-to-Neutral Relocation test were performed to assess neck kinaesthesia. Horizontal smooth pursuit eye movements were measured using video-oculography. Linear regression was used to determine the relationship between neck kinaesthesia, body sway and oculomotor control. RESULTS: Time-on-target in Butterfly test was able to predict low to medium proportions of variance in amplitude and velocity parameters for single leg stances in hockey players (R2 = .220-.698). Head-to-Neutral Relocation test was able to predict low to medium proportion of variance in average eye movement velocity during first 100 milliseconds of smooth pursuit initiation for both groups (R2 = .262-.541). SIGNIFICANCE: Findings from our study suggest that cervical spine afferent input plays an important role in maintaining unilateral postural balance in hockey players, with less evidence presented in controls. Sports specific posture or upper body loading could lead to adaptations in neck proprioception, not frequently considered when searching for balance related injury risk factors or performance deficits. Our study suggests, that in addition to balance control, neck kinaesthesia can also affect oculomotor performance which was present in both groups. This is especially evident when initiating changes in eye movement direction.

The Relationship Between Army Physical Fitness and Functional Capacities in Infantry Members of the Slovenian Armed Forces.

ABSTRACT: Simenko, J, Kovcan, B, Pori, P, Vodicar, J, Vodicar, M, and Hadzic, V. The Relationship between army physical fitness and functional capacities in infantry members of the Slovenian Armed Forces. J Strength Cond Res 35(12): 3506-3512, 2021-The primary purpose of this study was to determine the relationship between traditional army physical fitness test (APFT) and a novel functional testing battery that included countermovement jump (CMJ) testing, stork balANce test, pUll-ups, single leg hAmstring bridge test, and loaded prone pLank test-MANUAL battery. The secondary purpose was to explore additional baseline fitness aspects traditionally not covered by APFT. This cross-sectional study involved 181 Slovenian Armed Forces (SAF) infantry members (age 31.4 ± 6.1 years) that were tested using both the regular annual APFT and the MANUAL battery (testing was conducted 2 weeks apart). At the significance level of p ≤ 0.05, significant but weak associations between the MANUAL testing battery and APFT battery (0.2 ≤ r < 0.5; p ≤ 0.05) were observed. The MANUAL battery has highlighted possible hamstring (less than 20 repetitions on a single leg bridge test in 26% of SAF infantry members) and posterior shoulder pull-up muscle weakness (mean score 5 ± 4 pull-ups). Functional predictors from the MANUAL explained only 33.6% of the APFT score (R2 = 0.336). Significant predictors of APFT score were single leg hamstring left (p = 0.048), loaded plank (p = 0.049), number of pull-ups (p < 0.001), CMJ (p = 0.01), and loaded CMJ (p = 0.026). The findings suggest that higher APFT marks are associated with better performance on the MANUAL tests and indicate the problem of hamstring and pull-up muscle weakness. The general recommendation is that the physical condition military programs should include more exercises to strengthen those muscle groups.

Cross-cultural adaptation and validation of the Slovenian version of the Core outcome measures index for low back pain.

BACKGROUND: To conduct a cross-cultural adaptation and validation of the Core Outcome Measures Index (COMI) in the Slovenian language, for use in patients with low back pain. METHODS: The English version of COMI was translated into Slovene following established guidelines. Three hundred fifty-three patients with chronic low back pain were recruited from the Orthopedic clinic department of a tertiary care teaching institution. Data quality, construct validity, responsiveness, and test-retest reliability of the COMI were assessed. RESULTS: The questionnaire was generally well accepted with no missing values. The majority of items exhibited only mild ceiling effects (below 20.0%) and somewhat more prominent floor effects, which were similar to previous studies (4.5-78.8%). Correlations with Oswestry Disability Index (ODI) were high (ρ = 0.76 between overall COMI and ODI scores), suggesting that the Slovene version of COMI had high construct validity. Additionally, the Slovene version of COMI successfully captured surgical patients' improvement in their low back problem after surgery (overall COMI score change: Z = - 9.34, p < .001, r = - 0.53) and showed acceptable test-retest reliability (ICC = 0.86). CONCLUSIONS: The Slovene version of COMI showed good psychometric properties, comparable to those of previously tested language versions. It represents a valuable instrument for the use in future domestic and multicenter clinical studies.

Vertebral End-Plate Perforation for Intervertebral Disc Height Preservation After Single-level Lumbar Discectomy: A Randomized-controlled Trial.

STUDY DESIGN: Pilot single-centre, stratified, prospective, randomized, double-blinded, parallel-group, controlled study. OBJECTIVE: To determine whether vertebral end-plate perforation after lumbar discectomy causes annulus reparation and intervertebral disc volume restoration. To determine that after 6 months there would be no clinical differences between the control and study group. SUMMARY OF BACKGROUND DATA: Low back pain is the most common long-term complication after lumbar discectomy. It is mainly caused by intervertebral disc space loss, which promotes progressive degeneration. This is the first study to test the efficiency of a previously described method (vertebral end-plate perforation) that should advocate for annulus fibrosus reparation and disc space restoration. METHODS: We selected 30 eligible patients according to inclusion and exclusion criteria and randomly assigned them to the control (no end-plate perforation) or study (end-plate perforation) group. Each patient was evaluated in 5 different periods, where data were collected [preoperative and 6-mo follow-up magnetic resonance imaging and functional outcome data: visual analogue scale (VAS) back, VAS legs, Oswestry disability index (ODI)]. Intervertebral space volume (ISV) and height (ISH) were measured form the magnetic resonance images. Statistical analysis was performed using paired t test and linear regression. P<0.05 was considered statistically significant. RESULTS: We found no statistically significant difference between the control group and the study group concerning ISV (P=0.6808) and ISH (P=0.8981) 6 months after surgery. No statistically significant differences were found between ODI, VAS back, and VAS legs after 6 months between the 2 groups, however, there were statistically significant differences between these parameters in different time periods. Correlation between the volume of disc tissue removed and preoperative versus postoperative difference in ISV was statistically significant (P=0.0020). CONCLUSIONS: The present study showed positive correlation between the volume of removed disc tissue and decrease in postoperative ISV and ISH. There were no statistically significant differences in ISV and ISH between the group with end-plate perforation and the control group 6 months after lumbar discectomy. Clinical outcome and disability were significantly improved in both groups 3 and 6 months after surgery.

Long-term Results of Surgical Treatment for Symptomatic Anterior Cervical Osteophytes: A Case Series With Review of the Literature.

PURPOSE: Presentation of a case series (10 patients) with surgical treatment of symptomatic anterior cervical osteophytes, a review of the latest literature and discussion of surgical methods. OBJECTIVE: To present our results of the surgical treatment and compare them with the existing literature. On the basis of the gathered data, we aim to propose an optimal choice of surgical treatment. SUMMARY OF BACKGROUND DATA: Anterior cervical osteophytes rarely cause symptoms that require surgical treatment, which disables bigger cohort analysis. Surgery always includes anterior osteophyte resection. Some authors propose instrumented anterior fusion after osteophyte resection as the first choice of surgery in order to prevent regrowth of osteophytes, whereas others support resection without fusion because of beneficial long-term results. METHODS: Diagnostics included plain radiography, contrast esophagography, computed tomography and/or magnetic resonance imaging. Treatment consisted of left lateral cervicotomy and osteophytectomy. We performed a systematic review of the literature from 2006. RESULTS: Average age at surgery was 69.5 years (63-77 y), average follow-up 61.9 months (15-117 mo). Twenty-five osteophytes were resected, with average size of 12.7 mm (4-22 mm) preoperatively and 5.12 mm (0-12 mm) at final follow-up. Average functional outcome swallowing scale score before surgery was 3.3 (2-5) and 1.2 (0-5) at final follow-up. Only 1 patient had reoccurrence of symptoms because of osseous etiology. CONCLUSIONS: Symptomatic ventral cervical osteophytes can be successfully treated by surgery. In the majority of patients, osteophytes do not regrow significantly in the long term, precluding the need for prophylactic instrumented fusion after osteophyte resection.