Neck Strength Research Articles

Neck Strength Does Not Predict Time To Concussion Symptom Resolution Among Adolescents

Neck Strength Does Not Predict Time To Concussion Symptom Resolution Among Adolescents

Does Neck Strength Predict Repetitive Head Impacts In Youth Football Athletes?

Does Neck Strength Predict Repetitive Head Impacts In Youth Football Athletes?

Normative Scores and Test-Retest Reliability of Neck Strength, Endurance, and Proprioception Tests in Children and Adolescents

OBJECTIVE: To determine normative scores, test-retest reliability, and minimal detectable change for the neck flexor endurance test (NFET), craniocervical flexion test (CCFT), and joint position error test (JPET) in children. DESIGN: Cross-sectional. METHODS: Two hundred typically developing children (10-15 years) were recruited. Participants were screened for cervical spine instability using the alar and transverse ligament tests prior to administering the NFET, CCFT, and JPET. Testing was performed twice on the same day, 6 hours apart. RESULTS: For the younger age group, average NFET scores were as follows: females = 9.1 seconds, males = 10.1 seconds. Mean CCFT scores decreased with an increase in pressure (22 millimeters of mercury [mmHg]: females = 6.1 seconds [1], males = 6.8 seconds [1]; 30 mmHg: females = 4.07 seconds [1.1], males = 4.1 seconds [0.9]). For the CCFT, reliability reduced as pressure increased. The JPET had moderate reliability (ICC2, k = 0.4-0.63) with the highest error in right rotation (females = 14.1 cm [5], males = 13.4 cm [4.7]). The NFET had excellent reliability (ICC2, k = 0.96 [0.94-0.97], P<.001). CONCLUSION: The normative scores presented serve as a reference standard for future studies and for systematic screening and head and neck injury prevention. JOSPT Open 2024;2(4):348-353. Epub 20 May 2024. doi:10.2519/josptopen.2024.1135

Reliability of a Flight Helmet-Attached Force Gauge in Measuring Isometric Neck Muscle Strength

INTRODUCTION: Strong neck muscles may decrease the risk of flight-induced neck pain and possible disability among fast jet pilots. The purpose of this study was to examine the intra- and interrater reliability of a commercial force gauge attached to a pilot’s helmet for measuring isometric force production of the neck muscles. METHODS: A total of 41 subjects performed maximal isometric cervical flexion, extension, and lateral flexion in two measurement sessions for intrarater reliability, and 31 of these subjects participated in a third session for measuring interrater reliability. Delayed muscle soreness and neck pain were assessed using the Visual Analog Scale before and after each measurement session. The intraclass correlation coefficient (ICC) was used to compare values between the test and retest assessments. RESULTS: The overall interrater reliability was good (ICC 0.79–0.90), whereas the intrarater reliability varied from moderate to good (ICC 0.58–0.84). In both intra- and interrater reliability, the flexion test had good (ICC 0.84–0.89) reliability, while the lateral flexion test results had moderate to good (ICC 0.73–0.90) reliability. The extension test had the lowest reliability in both intra- (ICC 0.58) and interrater (ICC 0.79) tests. The average visual analog scale score (from 1–100 scale) prior to the second measurement session was 16 ± 18 in delayed muscle soreness and 0 ± 0 in neck pain. DISCUSSION: The present study demonstrated that the helmet-attached force gauge is a reliable, safe, and clinically applicable method to evaluate isometric neck strength in the flexion and lateral flexion directions. Honkanen T, Mattila V, Kinnunen O, Janhunen M, Sovelius R, Vaara JP, Kyröläinen H. Reliability of a flight helmet-attached force gauge in measuring isometric neck muscle strength. Aerosp Med Hum Perform. 2024; 95(10):788–793.

Neck Strength Variations in Dental Students with and without Neck Pain: A Longitudinal Study

Neck pain can induce specific motor responses and alterations in muscle strength. Therefore, this study aimed to investigate and compare the progression of cervical muscle strength within and between students with and without neck pain over the course of their first semester of clinical training. We used an online Nordic Musculoskeletal Questionnaire for group allocation, and neck strength in flexion, extension, and lateral flexion on both sides was measured using the KForce Bubble Pro hand-held dynamometer. Forty-four students were divided into neck pain (n = 21) and asymptomatic (n = 23) groups. Both groups increased neck strength by the end of the semester in flexion, extension, and left and right lateral flexion (p < 0.001). Students experiencing neck pain showed a significantly lesser degree of improvement (p = 0.036) in right lateral flexion. The agonist/antagonist ratios revealed an enhanced role of neck extensors across both groups. Dental students showed overall increased cervical strength in their first semester of clinical training. Those with neck pain exhibited a diminished rate of strength gain in right lateral flexion when compared with students without pain by the semester’s end, suggesting different neuromuscular adjustments to clinical practice in students experiencing pain, which may lead to functional impairments in later training stages.

Association between composite indices of femoral neck strength and odds of hip fracture.

With the increased incidence of hip fractures worldwide, numerous studies have reported that composite indices of femoral neck strength can improve hip fracture risk assessment. This study aimed to assess the association between composite indices of femoral neck strength and the odds of hip fracture in Chinese adults. This retrospective cross-sectional study conducted at Changzhou Second People's Hospital included 937 Chinese adults (248 with hip fractures). After overnight fasting for ≥ 8h, blood samples were collected from all participants within 24h of admission. Composite indices of femoral neck strength were derived by combining bone mineral density, weight, and height with femoral axis length and width, which were measured by dual-energy X-ray absorptiometry. In total, 937 participants (293 men and 644 women) were enrolled. The mean age was 68.3years (SD 10.5). After adjusting for confounders, higher values of CSI and ISI were associated with a lower odd of hip fracture. Increase in CSI (per 1g/m·kg) was associated with a 46% decrease in the odd of hip fracture (OR = 0.54; 95% CI, 0.39-0.74), and increase in ISI (per 0.1g/m·kg) was associated with an 82% decrease (OR, 0.18; 95% CI, 0.11-0.30). Effect sizes of CSI and ISI on the odds of hip fracture remained robust and reliable in subgroup analyses. Increased CSI and ISI were associated with a lower odd of hip fracture, especially in women, suggesting that composite indices of femoral neck strength may provide useful information for improving hip fracture risk assessment.

Between-Session Reliability of Field-Based Assessments of Isometric Neck Strength.

The reliability of the fixed-frame dynamometer for measuring isometric neck strength is established, but with limited field-based applications. This study aimed to establish the inter- and intra-session reliability of the peak force for neck flexors, extensors, and side flexors using the VALD ForceFrame and DynaMo and the force-time characteristics in the quadruped position (ForceFrame). Twenty-seven recreationally active males performed three repetitions of isometric neck flexion, extension, and side flexion over two sessions in random order using the VALD ForceFrame and DynaMo. Both devices demonstrated acceptable reliability, with the Forceframe ICC > 0.8 and CV% < 13.8% and the DynaMo ICC > 0.76 and CV% < 13.8%. No systematic or proportional differences were found using the Passing-Bablock procedure, and Bland-Altman analysis confirmed agreement across measures. Reliability was shown for right-side (ICC > 0.76) and left-side (ICC > 0.79) flexion and flexion (ICC > 0.75) across 50, 100, 150, and 200 ms. Statistical parametric mapping indicated no differences in ForceFrame-generated isometric force-time curves between sessions, though the CV was highest in the force development phase. The findings suggest that both tools can reliably assess neck strength, supporting their use in sports and clinical settings. However, assessment methods are not interchangeable, emphasising the need for standardised neck strength assessment approaches.

Concussion Reduction in Division I and II Athletes: Effects of Simple Cervical Spine Exercise Regimen.

Primary preventative medicine lacks a consensus on effective concussion prevention strategies for collegiate athletes. Cervical strength has been identified as a potential factor in concussion risk reduction. This study evaluates the impact of a commercially available, portable cervical muscle stretching and strengthening device, NeckX®, on cervical strength, range of motion (ROM), and concussion incidence in collegiate athletes participating in high-concussion-risk sports. A single-arm prospective cohort study was conducted with 162 collegiate athletes from various sports. Participants underwent a 12-week neck exercise protocol using the NeckX® device. Clinical data, including neck strength and ROM, were collected at weeks 0, 6, and 12. Concussion incidence was self-reported by participants and cross-referenced with records from the athletic department. Data were analyzed for significant neck strength and ROM changes throughout the 12-week study. A two-way analysis of variance multiple comparisons with the Tukey-Kramer significant difference test was utilized, using the Holm-Sidak method, with an alpha of 0.05. All athletic teams experienced a significant increase in cervical strength during the 12-week intervention (α = 0.05, p < 0.05). Increases in cervical flexion and extension force were most consistent between teams. Cervical ROM increased significantly in male and female soccer players (α = 0.05, p < 0.05). The overall incidence of head and neck injuries, including concussions, was reduced to 6.60% during the study period, the lowest recorded value in the university's athletic department history. The use of the NeckX® device for 12 weeks was effective in enhancing pericervical muscle strength and ROM while reducing concussion incidence in collegiate athletes participating in high-concussion-risk sports. Interestingly, the positive outcomes were consistent for both males and females, indicating the universal advantages of neck training among collegiate athletes. These findings support existing research on the benefits of cervical strengthening exercises for reducing concussions in collegiate athletes and highlight the convenience and affordability of using this device.

Effects of two types of resistance training modalities (hypertrophy vs. contrast training) on bone parameters in a group of healthy elderly women

The aim of the present study was to explore the effects of two types of resistance training modalities (hypertrophy training vs. contrast training) on bone health parameters in a group of healthy elderly women. Forty-nine healthy elderly women whose ages range between 60 and 70 years were included in this study. The study population was randomly divided into three groups: hypertrophy training group (HTG; n=16), contrast training group (CTG; n=16) and control group (CG; n=17). Bone mineral density (BMD) values at the whole body (WB), lumbar spine (L1-L4), total hip (TH) and femoral neck (FN) were measured by DXA before and after 12 months of resistance training. Composite indices of femoral neck strength were calculated. WB BMD, L1-L4 BMD, TH BMD and FN BMD increased in the contrast training group. WB BMD and L1-L4 BMD increased in the hypertrophy training group, while TH BMD and FN BMD remained unchanged. Significant decreases in WB BMD, L1-L4 BMD, TH BMD and FN BMD were observed in the control group. The contrast training group showed the highest improvements in BMD values compared to the two other groups. Both experimental groups (HTG and CTG) showed similar significant improvements in composite indices of femoral neck strength and muscular strength. In conclusion, contrast training and hypertrophy training can stimulate bone gain at clinically important sites of osteoporotic fractures in elderly women.

Family-Resourced Early Intervention Program for Motor Development in Cerebral Palsy Children

This research was conducted to determine the results of implementing an early intervention program Family resource for children's motor development applied to cerebral children palsy aged 4 years. The research method used in this research is research. The experiment takes the form of Single Subject Research (SSR) with data collection techniques including GMFM and GMFCS tests, interviews, and observations. The results of this research, this program has successfully demonstrated significant progress in control development better head in children. This increase can be seen from the longer duration in Doing various activities shows that the child has started to have neck strength enough to support the head, especially when sitting with assistance. Results from research It is hoped that this can become a reference for educators, especially in improving motor development of children with cerebral palsy at an early age.

Head Kinematics and Injury Analysis in Elite Bobsleigh Athletes Throughout a World Cup Tour.

The neurocognitive health effects of repetitive head impacts have been examined in many sports. However, characterizations of head impacts for sliding-sport athletes are lacking. To describe head impact kinematics and injury epidemiology in elite athletes during the 2021-2022 Bobsleigh World Cup season. Cross-sectional study. On-track training and competitions during the Bobsleigh World Cup season. Twelve elite bobsleigh athletes (3 pilots [1 female], 9 push athletes [5 females]; age = 30 ± 5 years; female height and weight = 173 ± 8 cm and 75 ± 5 kg, respectively; male height and weight = 183 ± 5 cm and 101 ± 5 kg, respectively). Athletes wore an accelerometer-enabled mouthguard to quantify 6-degrees-of-freedom head impact kinematics. Isometric absolute and relative neck strength, number of head acceleration events (HAEs), workload (J), peak linear velocity (m·s-1), peak angular velocity (rad·s-1), peak linear acceleration (g), and peak angular acceleration (rad·s-2) were derived from mouthguard manufacturer algorithms. Linear mixed-effect models tested the effects of sex (male versus female), setting (training versus competition), and position (pilot versus push athlete) on the kinematic variables. A total of 1900 HAEs were recorded over 48 training and 53 competition days. No differences were found between the number of HAEs per run per athlete by sex (incidence rate ratio [IRR] = 0.82, P = .741), setting (IRR = 0.94, P = .325), or position (IRR = 1.64, P = .463). No sex differences were observed for workload (mean ± SD: males = 3.3 ± 2.2 J, females = 3.1 ± 1.9 J; P = .646), peak linear velocity (males = 1.1 ± 0.3 m·s-1, females = 1.1 ± 0.3 m·s-1; P = .706), peak angular velocity (males = 4.2 ± 2.1 rad·s-1, females = 4.7 ± 2.5 rad·s-1; P = .220), peak linear acceleration (male = 12.4 ± 3.9g, females = 11.9 ± 3.5g; P = .772), or peak angular acceleration (males = 610 ± 353 rad·s-2, females = 680 ± 423 rad·s-2; P = .547). Also, no effects of setting or position on any kinematic variables were seen. Male athletes had greater peak neck strength than female athletes for all neck movements, aside from right-side flexion (P = .085), but no sex differences were noted in relative neck strength. We provide a foundational understanding of the repetitive HAEs that occur in bobsleigh athletes. Future authors should determine the effects of repetitive head impacts on neurocognitive function and mental health.

Biomechanical evaluation of a central collinear entry reconstruction nail for femoral neck fracture prophylaxis

IntroductionReconstruction nails are commonly used to treat proximal femur fractures, with cephalic screw placement for femoral neck “prophylaxis” becoming standard practice. These implants are traditionally introduced through piriformis fossa (PF) or greater trochanter (GT) entry portals. A third “central collinear” (CC) portal has been proposed that allows entry along the femoral anatomic axis and central placement of cephalic screws. The present study aimed to quantify and compare the CC portal femoral neck strength with the two traditional (PF and GT) entry portals. Materials and MethodsEighteen cadaveric femur specimens (nine matched pairs) were divided into three groups using a balanced incomplete block design to control for variations in age and sex: (1) GT, (2) CC, and (3) PF entry points. Specimens and implants were cut to a standard length and instrumented with straight or valgus bend nails of appropriate laterality and two cephalic screws. Specimens were mounted on a custom jig replicating load distribution along the mechanical axis. A 100 N compressive preload was applied to the femoral head, followed by loading to failure at a rate of 10 mm/s until fracture, indicated by 30 % drop in axial force. Results: The three entry points did not differ in load-to-failureGT (6378.7 ± 1494.9 N), P (6912.4 ± 4924.1 N) and CC (7044.2 ± 2911.4 N) (P = 0.948) or maximum displacement, stiffness, and toughness. Most PF specimens failed at the basicervical neck, whereas most GT specimens failed at the subcapital neck; these differences were not significant. CC specimens failed evenly split between subcapital and basicervical. ConclusionThere were no significant difference in femoral neck load-to-failure after placement of a reconstruction nail through a CC entry portal when compared to both GT and PF entry. Clinically, this suggests the CC entry portal is a viable option when clinical considerations warrant its use.

Changes in bone density and structure of proximal humerus with aging in Chinese women

AimsThis study aimed to investigate age- and menopause-related differences in bone mineral density (BMD), bone structure and estimated bone strength at surgical neck of humerus in Chinese female sample. MethodsWe conducted a cross-sectional cohort study of 171 Chinese women. Bone mass, indices of geometric properties and estimated mechanical strength of the surgical neck were evaluated by quantitative computed tomography (QCT). Comparisons were performed across menstrual status categories. Age-related changes in QCT-derived bone parameters were calculated. ResultsThe age-related difference of BMD and cortical thickness was 40.25 % and 32.86 % between the age of 20 and 86 years. Progressive periosteal and endosteal expansion was associated linearly with age. Estimated mechanical strength indexes showed significant quadratic associations with age, with their peak occurred at the age of 46–55 years. The quartile of women with the greatest medullary diameter also had the lowest valve of BMD and cortical thickness and the greatest in skeletal width. Compared to premenopausal individuals, perimenopausal women were distinguished by lower cortical thickness (18.63 %) and BMD (20.05 %). The continued decrease in cortical thickness and BMD was noted after menopause. The medullary and periosteal diameter increased by 17.98 % and 9.34 % respectively in perimenopausal period, but not after menopause. The accelerated loss of the maximum and polar section modulus was observed in late postmenopausal women. ConclusionsThe increase in bone size only occurred during the menopause transition. Obvious loss of resistance to bending was in late postmenopausal period.

Evaluating a 14-week neck strengthening protocol for neuromuscular indicators associated with head and neck trauma

Increased neck strength has been linked to a potential decrease in traumatic brain injuries (TBI). The purpose was to determine the efficacy of a neck-strengthening protocol using a novel neck-strengthening device to increase isometric neck strength and rate of force development (RFD). Utilizing self-generated centripetal force, participants trained for 14 weeks. A linear mixed model was used to analyze the relationship between post-assessment measurements and pre-assessments measurements, while accounting for repeated measure random effect at the individual level, and a regular random error term. RFD values were 4.344 times higher in the clockwise direction and 5.978 times higher in the counterclockwise direction when comparing pre and post assessment measurements. Isometric neck strength increased significantly (p ​< ​0.05) in the cervical extension (p ​= ​0.010) and left lateral flexion (p ​= ​0.009) directions. The results can be used in strength training and clinical settings to potentially reduce the incidence of TBI.

The Effect of Exercise-Induced Central Fatigue on Cervical Spine Joint Position Error, Strength, and Endurance.

Fatigue is common in sports, impairing performance and increasing injury risk, yet little is known regarding fatigue and concussion. Impaired neck neuromuscular function may contribute to concussion at baseline, where central fatigue may further impair neck function resulting in increased concussion risk. These effects may be magnified in athletes with a history of concussion. To determine the effect of exercise induced central fatigue on neck joint position error, strength, and endurance in healthy subjects and those with a history of concussion. The investigators hypothesized that EICF would have a negative effect on all variables. Healthy subjects were examined using a single factor, within-subjects repeated measures design. Concussion history subjects were examined using a single-subject design. Nineteen healthy subjects and five subjects with a history of concussion were recruited for the study. Cervical joint position error, muscle strength, and neck flexor endurance were tested before and after exercise induced fatigue. There was a significant increase in constant (p = 0.0027) and absolute joint position error (JPE) (p < 0.001); decrease in neck flexor endurance (p < 0.001); and decrease neck strength into cervical flexion (p = 0.01) in healthy subjects following fatigue. Among concussion history subjects, five demonstrated a significant increase in absolute and constant JPE (p < 0.05); four demonstrated a significant decrease in neck flexor endurance (p < 0.05); one in neck flexion muscle strength (p < 0.05); and three in neck extension and rotation muscle strength (p < 0.05) following fatigue. Cervical neuromuscular function deteriorated following fatigue in healthy subjects. Resulting impairments may affect force alterations in cervical control, potentially increasing concussion risk. Concussion history subjects descriptively demonstrated similar results, however further research should examine formal comparisons involving subjects with and without concussion history. 3b.

Risk Reduction of Concussion in Athletes: Do Neck Size or Neck Strength Make a Difference?

Medical provider's ability to detect, diagnose, and treat sport-related concussion has greatly improved in recent years. Although more is known about the biomechanical forces involved in concussion, it is still uncertain whether there are preventative measures athletes can take to prevent a sport-related concussion from occurring. The objective of this review was to determine if either neck size or neck strength is related to a decreased risk of sustaining a sport-related concussion. A literature review was conducted on Google Scholar and Ovid MEDLINE for pertinent articles. Findings indicate that isometric neck strength, but not neck size, has been shown to be a predictor for sport-related concussion prevention. Formal neck strengthening programs are feasible and lead to decreased sport-related concussion risk. Additionally, there may be greater opportunity to increase neck strength in amateur athletes compared to professional. In conclusion, cervical strengthening programs have been shown to be feasible and beneficial for athletes to decrease their risk of sustaining a sport-related concussion, though the optimal duration, intensity, and frequency has yet to be determined.

EFFECTS OF CERVICAL MUSCLES STRENGTHENING WITH AND WITHOUT SHOULDER EXERCISES IN POST-MASTECTOMY PATIENTS WITH NECK PAIN

Background of the Study: To compare the effects of cervical muscles strengthening with and without shoulder exercises on post- mastectomy patients with neck pain. Methodology: It was a randomized clinical trial, conducted in physical therapy department of a clinical setting through Dynamometer. Sample size of 24 patients were taken. Non-probability convenience sampling technique was used. A written consent form was taken from patients meeting inclusion criteria and were randomly allocated. In one group, patients were treated with cervical Muscles strengthening with shoulder exercises. In other group, patients were treated with cervical Muscles strengthening alone. Treatment was given once a day for three weeks. Muscle strength was examined using dynamometer, Baseline data was taken before treatment on first day after inclusion in study and again on the last day after treatment. SPSS 25 was used to analyze the data. Results: Wilcoxon signed rank test was used to compare individuals within the group which showed significant results in both groups, p-value 0.000 (i.e. &lt;0.001) for neck strength. Between groups comparison was done using Mann-Whitney U Test and it showed no significant changes for cervical extensors (p- value;0.143) , cervical side bending (right) (p-value; 0.315) and cervical side bending (left) (p-value; 0.853) strength differences, but however cervical flexors strength showed statistically significant results as p-value was 0.003. Conclusion: It was concluded that Cervical strengthening along with shoulder Rehabilitation can help improve the strength of cervical flexors. However, both the groups have equally resulted in improved cervical extensor, Side bending right and left strength. Keywords: Cervical, mastectomy, muscle strength, rehabilitation, exercises, therapeutic.

Neck strength alone does not mitigate adverse associations of soccer heading with cognitive performance in adult amateur players.

Soccer heading is adversely associated with neurocognitive performance, but whether greater neck strength or anthropometrics mitigates these outcomes is controversial. Here, we examine the effect of neck strength or anthropometrics on associations of soccer heading with neurocognitive outcomes in a large cohort of adult amateur players. 380 adult amateur league soccer players underwent standardized measurement of neck strength (forward flexion, extension, left lateral flexion, right lateral flexion) and head/neck anthropometric measures (head circumference, neck length, neck circumference and neck volume). Participants were assessed for heading (HeadCount) and cognitive performance (Cogstate) on up to 7 visits over a period of two years. Principal components analysis (PCA) was performed on 8 neck strength and anthropometric measures. We used generalized estimating equations to test the moderation effect of each of the three PCs on 8 previously identified adverse associations of 2-week and 12-month heading estimates with cognitive performance (psychomotor speed, immediate verbal recall, verbal episodic memory, attention, working memory) and of unintentional head impacts on moderate to severe central nervous system symptoms. 3 principal components (PC's) account for 80% of the variance in the PCA. In men, PC1 represents head/neck anthropometric measures, PC2 represents neck strength measures, and PC3 represents the flexor/extensor (F/E) ratio. In women, PC1 represents neck strength, PC2 represents anthropometrics, and PC3 represents the F/E ratio. Of the 48 moderation effects tested, only one showed statistical significance after Bonferroni correction, which was not robust to extensive sensitivity analyses. Neither neck strength nor anthropometrics mitigate adverse associations of soccer heading with cognitive performance in adult amateur players.

Investigation of Neck and Shoulder Muscle Strength by Scapula-Spinous Distance Difference in Individuals with Shoulder Impingement Syndrome

Omuz sıkışma sendromu stabilite ve mobilitede etkili olan yapıların subakromial arkta sıkışması ile oluşan kompleks bir durumdur. Bu duruma çeşitli faktörler sebep olmaktadır. Skapular diskinezi omuz sıkışma sendromu olan hastalarda sıklıkla görülen bir bulgu olup kas kuvvet dengesizliği ile ilişkilidir. Bu çalışmanın amacı omuz sıkışma sendromu olan bireylerde skapula-spinöz mesafe ile boyun ve omuz kas kuvveti arasındaki ilişkinin incelenmesi ve sağlıklı kontrol grubuyla karşılaştırılmasıdır. Araştırmaya omuz sıkışma sendromu tanısı alan (deney grubu) 12 hasta ile 8 sağlıklı (kontrol grubu) birey olmak üzere toplam 23 kişi dahil edildi. Araştırmada skapular diskinezi değerlendirmesi için ‘Lateral Skapula Testi’, kas kuvveti ölçümü için el dinamometresi ile kas kuvvet testi, ağrı ve disabilite durumunu değerlendirmek için ‘Omuz Ağrı ve Özürlülük (SPADI)’ ölçeği kullanıldı. İstatiksel analiz için Shapiro-Wilks testi, bağımsız örneklemler t-testi ve Mann-Whitney U testi kullanıldı. Deney ve kontrol grubunun skapular asimetri bakımından benzer oldukları belirlendi (p&gt;0,05). Deney grubunda etkilenmiş taraf omuz fleksör, ekstansör, horizontal abdüktör, horizontal addüktör, internal rotatör ve eksternal rotatör kas kuvvetinin kontrol grubuna göre daha zayıf olduğu belirlendi (p

The effect of ball pressure and maximal isometric neck strength on head acceleration during purposeful heading in adult football players during heading drills

ObjectiveThis randomised repeated measures study explored the effect of ball pressure and maximal isometric neck strength on head acceleration during purposeful heading in adult football players during heading drills within a laboratory environment. MethodsRecreational football players (n ​= ​17) attended one familiarisation session to determine baseline maximal isometric neck strength, followed by two experimental sessions where they randomly trialled two conditions (>72-h apart). The first condition included 20 rotational headers with a match-ball at low-pressure (58.6 ​kPa; 8.5 psi) and the second included 20 rotational headers with a match-ball at high-pressure (103.4 ​kPa; 15.0 psi) whilst instrumented with an inertial measurement unit. ResultsA statistically significant difference between conditions for both peak linear head acceleration (F ​= ​15.2; p= ​ < ​ 0.001) and peak angular head velocity (F ​= ​5.71; p ​= ​0.018) during purposeful heading. The low-pressure ball condition demonstrated a 12 ​% reduction in peak linear acceleration and 6 ​% reduction in peak angular velocity when compared with high-pressure ball condition. Additionally, neck strength significantly predicted head acceleration during purposeful heading (p ​ = ​ <0.05). ConclusionThese findings suggest that lower ball pressure and higher neck strength can lower head acceleration during heading in adult football players during heading drills within a laboratory environment.