Table 1 Details of identified studies
Author | Participants | Study design | Year | Intervention | Outcomes | Key findings |
|---|---|---|---|---|---|---|
Theme 1. Cervical spine and contact sport participation 1.1 Epidemiology of cervical injuries | ||||||
Mueller [33] | N/A | Literature review | 1998 | N/A | N/A | Dramatic reduction in fatalities 1975 through 1994 1976 rule change that prohibited initial contact with the head and face when blocking and tackling |
Cantu [31] | 183 High School 29 Collegiate 7 Professional | Retrospective review of injury records | 2003 | N/A | Catastrophic spine injuries in football | Incidence rate of 0.52 in high school, 1.55 in college, and 14 in professional football for every 100,000 participants A 270% reduction in catastrophic injuries was observed following 1976 rule change |
Fuller [39] | Professional Soccer athletes | Case control | 2005 | N/A | Cervical Injury rates | Most frequent injuries were contusions (53%), lacerations (20%), and concussions (11%) The incidence of all head and neck injuries was 12.5/1000 player hours (men 12.8, women 11.5) and 3.7 for lost-time injuries (men 3.5, women 4.1) Frequent mechanisms of injury involved aerial challenges (55%) and use of the upper extremity (33%) or head (30%) |
Nilsson [40] | 26 European soccer teams between 2001/2002 -2009/2010 | Prospective cohort study | 2013 | Professional Soccer participation | Injury rate (number of time loss injuries per 1000 h) | 136 head and neck injuries were recorded (2.2% of all injuries) Injury rate was 0.17 (0.06 concussions) per 1000 h 20-fold higher rate of head and neck injury during match play compared with training (rate ratio[RR], 20.2; 95% [CI] 13.3–30.6) and a 78-fold higher rate of concussions (RR, 78.5; 95% CI 24.4–252.5) |
Hutton [32] | N/A | Systematic review | 2016 | N/A | Incidence catastrophic cervical injuries | Among Rugby Union players, incidence of catastrophic cervical spine injury (CCSI) was 4.1 per 100,000 player-hours Among NFL players, the CCSI rate was 0.6 while collegiate rate ranged from 1.1 to 4.7 per 100,000 player-years CCSI rate of 1.4–7.2 per 100,000 player-years |
Meron [36] | National High School Sports-related Injury Surveillance system | Retrospective review of records | 2017 | N/A | Cervical spine injury rates | 1080 cervical spine injuries were reported during 35,581,036 athletic exposure (AE), resulting in an injury rate of 3.04 per 100,000 AE Cervical spine injuries were highest in football (10.10), wrestling (7.42) and gymnastics (4.95) Muscle injuries were the most common (63.1%), followed by nerve injuries (20.5%) The most common mechanisms of injury were contact with another player (70.7%) and contact with playing surface (16.1%) |
Simmons [37] | Ice hockey NCAA Injury Surveillance Program 2009–2014 | Descriptive epidemiology study | 2017 | N/A | Head and neck Injury rates per 1000 AE | Injury rate was higher in men than in women (1.75 vs. 1.16/1000 AE; CI = 1.25, 1.84) The most common head and neck injury was concussion; most concussions occurred in men's competitions from player contact while checking (25.9%) |
Williams [38] | 3 NCAA Division I universities from 2007 to 2012 | Descriptive study | 2017 | Head and neck injury rates per 10,000 AE | Overall injury rate was 35.2 per 10,000 athletic exposure (AE)s Rates for initial and subsequent injuries were 31.7 and 45.3 per 10,000 AEs, respectively, with a rate ratio (RR) of 1.4 for rate of subsequent injury vs rate of initial injury (95% CI 1.1–1.9) Subsequent injuries to the head, neck, and face were nearly double the rate of initial injury to same site (10.9 per 10,000 AEs, RR = 2.0; 95% CI 1.1–3.5) | |
Chung [34] | Collegiate football players in the NCAA database | Descriptive study | 2019 | N/A | Cervical spine injury rates | 300 cervical Injuries were identified in the data representing an estimated 7496 total cervical spine injuries extrapolated from the observed population to entire NCAA Injury rate of 2.91 per 10,000 AEs Most common was stinger with 1.8/10000 AEs and cervical strains with 0.8/10000 AEs Injuries were highest among defensive players |
Lee [35] | High school and collegiate athletes from national sport injury surveillance databases | Retrospective record review | 2019 | N/A | Cervical injury counts and rates/10,000 AE | The NCAA database reported 49 cervical muscle strains (rate = 0.96/10000 AEs), (57.1%) were time loss injuries (rate = 0.55/10, 000 AEs) High School databases reported 184 cervical muscle strains (rate = 1.66/10, 000 AEs), of which 33 (17.9%) were time-loss injuries (rate = 0.30/10,000 AEs) -The overall injury rate was lower among collegiate athletes than high school (injury rate ratio = 0.58; 95% CI = 0.42, 0.79) |
Theme 1. Cervical spine and contact sport participation 1.2 Morphological changes to the cervical spine in contact sport athletes | ||||||
Sortland [3] | 43 national soccer players from Norway 43 matched control | Cross-sectional | 1982 | Exposure to professional soccer | Spinal axis, healed fractures, cervical degenerative changes | Compared with men of the same age group the onset of degeneration was 10–20 years earlier and the frequency of degeneration was significantly higher in retired professional soccer players Degenerative changes were not especially high in among individuals who reported higher heading frequency but this group had a higher frequency of subjective complaints and clinical findings such as reduced cervical movements |
Kuman [43] | 30 Athletes | Cross-sectional observational | 1986 | Treatment of rest and traction versus referral for surgery | Time to recovery radicular symptoms vs no radicular symptoms | 60% of radicular signs and symptoms were from the 4th and 5th cervical intervertebral space Roentgenographic changes were most common at the 4th and 5th cervical root Most cases responded favorably to conservative treatment of traction and rest Patients who presented with radicular signs and symptoms required up to 5 months to return while athletes with no radicular signs returned in less than 3 weeks |
Tysvaer [47] | 69 active soccer players and 37 retired Norwegian national team members | Cross sectional | 1992 | Exposure to professional soccer | Computerized tomography electroencephalogram (EEG) | Head injuries account for between 4 and 22% of soccer injuries There were fewer abnormal EEG changes among typical 'headers'(10%) than among 'nonheaders' (27%) One-third of the players were found to have central cerebral atrophy and 81% to have from mild to severe neuropsychological impairment The radiological examination of the cervical spine revealed a significantly higher incidence and degree of degenerative changes than in a matched control group |
Torg [46] | 5 groups of individuals based on graded amount of years of exposure to football | Descriptive study | 1996 | Exposure to football | Torg ratio | A torg ratio (Diameter of spinal canal/diameter of the vertebral body) of 0.80 or less had a high sensitivity (93%) for transient neurapraxia Developmental narrowing of the cervical canal in a stable spine does not appear to predispose an individual to permanent catastrophic neurological injury and therefore should not preclude an athlete from participation in contact sports |
Quarrie [45] | N/A | Review article | 2002 | N/A | N/A | Majority of injuries occur early in the season, when players are lacking both practice and physical conditioning for the physical contact phases of the sport Hookers and props have been at disproportionate risk of cervical spine injury, predominantly because the scrum was the phase of play most commonly associated with spinal injuries |
Kartal [8] | 15 veteran, 15 current, 28 age matched controls soccer players | Cross-sectional descriptive study | 2004 | Exposure to soccer | Cervical strength Cervical RoM Cervical X-ray Spinal cord compression | Degenerative changes were prominent in veteran players, and the sagittal diameter spinal canal at C5 to C7 was lower when compared to active players and controls Magnetic resonance findings of degeneration were more prominent in soccer players when compared to their age-matched controls A tendency towards early degenerative changes exists in soccer players |
Bailes [45] | Ten contact sport athletes | Cross-sectional Observation | 2005 | N/A | X-ray and CT with dynamic studies | The occurrence of TSCI is not uncommon in athletes involved in contact sports Transient spinal cord injuries appear among those in yet whom radiographic studies are normal, and those with cervical stenosis, the later is the most difficult management group |
Mehnert [9] | N/A | Review | 2005 | N/A | N/A | Existing studies of long-term effects suggest a predisposition to degenerative changes of the cervical spine Further research in this area is needed with studies that assess biomechanical forces under simulated play conditions and control for impacts and stresses to the neck and spine that occur from non-heading activity |
Ivancic [48] | 10 cadavers | Pre-post Experimental | 2013 | Crash simulation | Intact and postimpact flexibility test, axial torque and lateral bending | Multidirectional instability of the upper cervical spine caused by atlas and dens fractures was evidenced by increases up to 53% in cervical flexion and extension due to impacts Increases in extension range of motion were 14.9 degrees in the upper cervical spine and 24.9 degrees (p < 0.05) at the middle cervical spine and in flexion at C7/T1 were 25.6 degrees |
Brauge [42] | 101 former rugby players (mean age 40.4) 85 aged matched controls | Cross-sectional | 2015 | Participation as a professional rugby athlete | Japanese orthopaedic questionnaire Neck disability MRI | Rugby players complained of chronic neck and decreased mobility pain more frequently (51 of 101 vs. 27 of 85, p = 0.01) Rugby players had a narrower vertebral canal(0.88 ± 0.167 cm vs. 0.99 ± 0.130 cm, p = 0.007) and more foraminal stenosis (p = 0.01) Rugby players had more often undergone surgery for a degenerative condition than controls (10 cases vs. 0, p = 0.0021) |
Trewartha [49] | N/A | Literature Review | 2015 | N/A | N/A | Scrummaging leads to premature chronic degeneration of the cervical spine Biomechanical studies of rugby scrummaging confirm that scrum engagement forces are high and multiplanar, but can be altered through modifications to the scrum engagement process to control engagement velocity The incidence of acute injury associated with scrummaging is moderate but the risk per event is high |
Ndubuisi | 204 symptom free adults, 21–50 years of age | Cross-sectional | 2017 | Exposure to active leisure contact sports | Space available for the Cord (SAC) | SAC at C3-4 was 4.39 ± 0.28 mm contact sport group and 4.90 ± 0.30 mm in controls (p = 0.036) and at C4-5 was 4.16 ± 0.27 mm contact sport group and 4.56 ± 0.35 mm (group B) Significant effect of contact sports (p = 0.005), sex (p = 0.001), and age (p = 0.0001) were observed in relation to SAC |
Theme 1. Cervical spine and contact sport participation 1.3 Return to play considerations | ||||||
Cantu [51] | N/A | Informational | 1998 | N/A | Clinical criteria for diagnosis of cervical stenosis | Spinal stenosis can't be defined by bone measurement alone as this fails to control for dural compression Patients with functional spinal stenosis recovery far less frequently than those who have structural narrowing of the spine as measured by radiography Radiography is critical for initial work up to clear subluxation or fracture when symptoms are present |
Okonkwo [58] | N/a | Review | 2003 | N/A | N/A | Two million persons suffer a head injury each year in the United States; of these, approximately 350,000 are sports- and recreation-related head injuries Between 12,000 and 15,000 cases of spinal cord injury occur each year in the United States, of which 10–15% are sports-related Traumatic brain injury is the most common cause of death in persons under 45 in the western world |
Torg [59] | N/A | Systematic review | 2009 | N/A | N/A | The overriding principle regarding the return to football or any collision activity should be that the individual is asymptomatic, pain-free, and neurologically intact and have full cervical strength and range of cervical motion Any injury to C1-C2 is an immediate contraindication to contact sport participation |
Chao [52] | N/A | Review article | 2010 | N/A | N/A | Catastrophic cervical injuries at are rare and account for less than 3% of cervical spine injuries Transient neurological episodes are estimated at 7/10,000 and typically resolve in 10–15 min but may last up to days Most frequent mechanism of brachial plexus injury is traction and are associated with athletes with a higher rate of cervical stenosis, disk disease and other degenerative conditions |
Dailey [53] | N/A | Clinically based systematic review | 2010 | N/A | N/A | Weak recommendation that patients with transient neuropraxia and radiographic evidence of cervical canal compromise should be withheld from participation in contact sports Strong recommendation that patients with transient neuropraxia without radiographic evidence of cervical stenosis can return to full sports activities |
Kepler [55] | N/A | Expert opinion | 2012 | N/A | N/A | Benign injury types such as isolated spinous process fractures or compression fractures can be treated with immobilization and typically do not preclude return to play once healed Complex injuries must be evaluated based on spinal stability, need for fusion, and the number of levels fused if necessary; fusion of 3 or more cervical levels is a contraindication to return to play Players with a third stinger in a single season or a recurrent transient quadriparesis must undergo imaging to rule out stenosis and parenchymal injury; return to play is dependent on resolution of symptoms and severity of episode |
Mcana [57] | N/A | Commentary | 2014 | N/A | N/A | Cervical spondylolysis, unlike lumbar spondylolysis, is an exceedingly rare only 150 have been reported Limited knowledge is known about RTP guidelines following cervical spondylolysis |
Joaquim [54] | N/A | Systematic Review | 2016 | N/A | Relief of symptoms, RTP, career length after surgery, and permanent neurological deficits | Return to play is safe for athletes who are asymptomatic after disk fusion for cervical radiculopathy due to disc herniation Surgical treatment may provide a higher rate of return to play for these athletes than nonsurgical treatment Cervical cord signal changes may not be an absolute contraindication for return to play in neurologically intact patients Cervical contusions secondary to cervical stenosis may be associated with a worse outcome and a higher recurrence rate than those secondary to disc herniation |
Theme 2: Cervical afferents and postural control 2.1 Artificially induced afferent cervical dysfunction alters neuromotor control and posture maintenance | ||||||
McLain [23] | 21 cervical facet capsules, taken from three normal human subjects | Cross-sectional | 1994 | N/A | Mechanorece-ptor count Nociceptive nerve ending count | The presence of mechanoreceptive and nociceptive nerve endings in cervical facet capsules proves that these tissues are monitored by the central nervous system Protective muscular reflexes modulated by these types of mechanoreceptors are important in preventing joint instability and degeneration |
Allum [20] | 4–10 controls 3–7 bilateral labyrinthine deficient patients (depending on experiment) | Cross-sectional | 1997 | Labyrinthine deficient vs normal control | EMG Head acceleration | Head velocities observed during balance corrections depend to a large extent on the movements of the head-neck mass-viscoelastic system whose properties could be altered by co-contracting the neck muscles For experiments involving stance perturbations, much of the corrective response in neck muscles appeared to be triggered by trunk and leg proprioceptive signals Cervical reflexes modulate the amplitude of functionally stabilizing responses and dampen mechanically induced instability of the head and neck |
MalmstrÃm [64] | 16 healthy subjects | Cross-sectional experimental | 2017 | Disturbance of cervical proprioception by vibration | Spatial body position | Significant differences were seen in posturography between no vibration (628 mm or 25.1 mm/s) relative to each vibration condition When vibration was applied on the left-sided muscles, rotation to the right was induced (p = 0.005) Cervical proprioception is a critical component of internal spatial orientation and postural control |
Theme 2: Cervical afferents and postural control 2.2 Cervical pathology is linked to altered neuromotor control and poor posture maintenance | ||||||
Karlberg [63] | 17 with cervicogenic dizziness 17 healthy controls | Randomized controlled trial | 1996 | Physical therapy to reduce symptoms | Vibration-induced body sway, intensity and frequency of neck pain | Neck pain patients manifested significantly poorer postural performance than did healthy subjects (0.05 > p > 0.0001) Physiotherapy significantly reduced neck pain and intensity and the frequency of dizziness (p < 0.01), and significantly improved postural performance (0.05 > p > 0.0007) |
Sjostrom [66] | 25 whiplash participant 170 healthy age-matched control participants | Cross-sectional | 2003 | Whiplash vs healthy | Trunk sway | Greater trunk sway for stance tasks and for complex gait tasks that required task-specific gaze control such as walking up and down stairs or walking while turning the head |
Treleaven [68] | 100 whiplash participants (50 dizziness/50 no dizziness) 50 healthy controls | Prospective observational design | 2005 | Whiplash with and without dizziness vs healthy control | Clinical test for sensory Interaction in balance | Energy of the sway signal for comfortable stance tests was significantly greater in the group with dizziness compared with the group without dizziness Subjects with dizziness were significantly less able to complete the test than subjects without dizziness and controls after controlling for medications, compensation, anxiety or age and are likely to be due to disturbances to the postural control system possibly originating from abnormal cervical afferent input |
Theme 3: Damage to cervical afferents and increased risk of injury | ||||||
Treleaven [67] | N/A | Masterclass | 2008 | N/A | N/A | The importance of the cervical reflex connections on postural control can be understood by observing changes in postural sway in response to artificial disturbances to the cervical afferents in asymptomatic individuals Dysfunction of the cervical receptors following injury to the cervical spine can alter afferent input subsequently changing the integration, timing and tuning of sensorimotor control of the extremities Afferent information from the cervical receptors can be altered via a number of mechanisms such as trauma and or functional impairment of the receptors, changes in muscle spindle sensitivity and the vast effects of pain at many levels of the nervous system |
Freppel [62] | 17 patients with degenerative cervical spine disease 31 healthy controls | Pre-test, post-test | 2013 | Surgery to correct either herniated disk or cervical degenerative disease | Displacement in center of foot pressure Static posture tests | C ontribution of visual input to postural control is reduced in a dynamic visual environment where cervical spine diseases is present The relative importance of visual and proprioceptive inputs to postural control varies according to the type of pathology and surgery tends to reduce visual contribution mostly in the spondylosis group |
Treleaven | 140 whiplash patient | Randomized controlled trial | 2016 | whiplash vs healthy control | Static and dynamic clinical balance tests and cervical joint position error | Between and within group comparisons suggest that physiotherapist led neck exercise groups had advantages in improving measures of dizziness compared with the general physical activity group, although many still complained of dizziness and balance impairment |
Wannaprom [69] | 30 adults withchronic neck pain 30 healthy control | Cross-sectional | 2018 | neck pain vs healthy control Vibration of suboccipital muscles | Balance in a comfortable stance and timed gait test using a 10 m walk test | At baseline, neck pain participants had greater postural sway, and slower gait speed than healthy controls (p < 0.001) Immediately after vibration, neck pain participants displayed decreased postural sway, and increased gait speed (p < 0.001) Neck muscle vibration improved standing balance and gait speed in participants with neck pain but reduced performance in healthy controls |
Reddy [65] | 132 subjects with cervical spondylosis (CS) and 132 healthy age-matched control | Cross sectional | 2019 | Cervical JPE testing, neck pain assessment, | Cervical spine injury subjects (CS) showed significantly larger cervical joint position sense error than healthy control subjects in all the directions tested(flexion, extension, right and left rotation) with a p value (< 0.001) Comparing all the movement directions in the CS and healthy control groups, the cervical joint position sense were largest in cervical extension (CS groups = 8.28° ± 1.80°; healthy group = 4.48° ± 1.26°) with standard error of measurements of 0.21° and minimal detectable change of 0.48° | |
Carrick [61] | 575 concussion patients 60 healthy controls | Repeated measures experimental | 2020 | Concussed vs healthy Changes in head position during static posture assessment | Computerized dynamic posturographic measurement | Postural stability scores are correlated with changes in head position in subjects following a concussion The position of the head and neck induced by statically maintained head turns is associated with significantly lower stability scores than the standardized head neutral position in Post-concussion Syndrome subjects but not in normal healthy controls Head positions on the neutral plane provide novel biomarkers that identify and differentiate subjects suffering from persistent post-concussion symptoms from healthy normal subjects |
Hammerle | 48 post-concussion patients with dizziness | Retrospective record review | 2019 | Vestibular vs. cervical therapy | Improvement in dizziness | Patients who received cervical specific therapy were 30 times more likely to report improvement in dizziness symptoms compared with those who received vestibular therapy alone (adjusted odds ratio: 30.12; 95% confidence interval 4.44–204.26, p < 0.001) when cervical spine symptoms were present |
Hides [72] | 190 Male rugby players 47 reported history of concussion | Prospective cohort study | 2017 | History of reported concussion | Balance Vestibular function Cervical Joint position error Trunk muscle function | A history of concussion was related to changes in size and contraction of trunk muscles 22 (11.6%) players sustained a head/neck injury during the playing season of which 14 (63.6%) players had a previous history of SRC Five risk factors in total were identified (cervical joint position error, history of concussion, and 3 measures of trunk muscle function) athletes with 3 or more were 14 times more likely to suffer a neck/head injury (sensitivity 75% and specificity 82) then players with 2 or fewer risk factors |
Hides [19] | 54 Professional rugby league players 14 suffered concussion | Prospective cohort study | 2017 | Pre/Post Concussion | Trunk muscle imaging Cervical joint position error Balance assessment | Significant decreases in sway velocity and increased size/contraction of trunk muscles, were identified following concussion Whilst not significant overall, large inter-individual variation of test results for cervical proprioception and the vestibular system was observed Preliminary findings Post-concussion suggest an altered balance strategy and trunk muscle control with splinting/over-holding requiring consideration as part of the development of appropriate physiotherapy management strategies |
Howell [27] | N/A | Scoping review | 2018 | N/A | N/A | Based on existing literature, athletes appear more likely to sustain a musculoskeletal injury in the year after sustaining a concussion There are no known mechanisms for the increase in lower extremity injury following concussion, but one contributing factor may be that continued neuromuscular control deficits exist for a longer period than standard clinical tests are equipped to identify |
Abdelkader [71] | 45 (18–40 years old) | Repeated measures | 2020 | Fatigue | Neck Reposition Error Postural control (biodex balance system multidirectional reach test) | Declines in postural stability were correlated with increased cervical joint position error Subjects suffering from cervical muscles fatigue are vulnerable to neck proprioception deficits and postural instability Clinicians and patients should avoid overload fatigue of the cervical muscles because it affects overall postural balance, neck proprioception & righting reaction |
Cheever [13] | 40 female colligate club soccer athletes | Repeated measures pre-test post-test design with 4 groups | 2020 | Instrumented head impacts Fatigue workout | Cervical joint position error test, Neck Disability Index | A 65%,54%,and49% increases in cervical joint position error were observed following soccer heading, fatigue only, and soccer heading + fatigue interventions, respectively. Meanwhile, the controls who did not head soccer balls or complete the fatigue protocol saw a 6% decrease in neck position error No difference between fatigue group and head impact group |
Cheever [14] | 27 contact sport athletes 20 controls | Cross-sectional | 2021 | History of contact sport participation | Cervical strength Cervical joint reposition error Neck Disability Index | Amateur sport athletes with a history of contact sport exposure exhibited 25.2% more total neck reposition error and 24.6% more maximum neck reposition error than athletes with no history of contact sport participation S/S number (r2 = 0.12, F(2,44 = 6.2, p = 0.017) and S/S severity (r2 = 0.14, F(2,44) = 5.6, p = 0.02) were significantly correlated with total neck reposition error |
Peng | N/A | Narrative Review | 2021 | N/A | N/A | Main problem in patients with neck pain is the impairment of cervical proprioception, which subsequently leads to cervical sensorimotor control disturbances Experimental neck muscle pain induced by injection of hypertonic saline results in significant inhibition of the activation of painful muscles suggesting chronic neck pain may cause structural and functional impairment of cervical muscles leading to excessive activation of mechanoreceptors in degenerative cervical discs and facet joints producing a large number of erroneous sensory signals |