Subconcussive head impact exposure in sports is a complex public health issue. Although many head impacts are asymptomatic, the near point of convergence (NPC) that measures the closest point of ...focus before diplopia occurs, has been shown to reflect subclinical neuronal damage. Studies have not been conducted on the effect of repeated head impact exposure due to falls from heights, like in pole vaulting. This study examines the NPC response in collegiate pole vaulters with indirect head impact history due to falls from heights. This prospective observational study included four-pole vaulters and three decathletes. The study was conducted during the end of the Japanese collegiate track and field season. The measurements were taken at pre-practice, 0 h post-practice, 24 h post-practice, 1 week post-practice, 2 weeks post-practice, 3 weeks post-practice, and 4 weeks post-practice. Players completed the NPC test and the symptom checklist. There was a significant difference in the NPC value at pre-practice and 4 weeks post-practice; P = 0.048. Compared to pre-practice values, NPC significantly increased at 0 h post-practice (mean SE values: pre-practice, 5.61 0.69 cm; 0 h post-practice, 7.31 0.79 cm; P = 0.02). At 3 weeks post-practice and 4 weeks post-practice, NPC values were significantly reduced compared to the values at 0 h post-practice (mean SE values: 0 h post-practice, 7.31 0.79 cm; 3 weeks post-practice, 5.75 0.61 cm; 4 weeks post-practice, 5.52 0.64 cm). This study reveals that NPC can be impaired by pole vaulting. The increased NPC returned to normal after 3 - 4 weeks of rest.
This study aimed to evaluate how a two-week program using the in-phase mode of a balance adjustment system (the BASYS) affected postural control in participants with chronic ankle instability (CAI). ...It was hypothesized that the in-phase mode on the BASYS would lead to improved postural control compared with training on a balance disc.
Randomized control trial.
Twenty participants with CAI were recruited. The participants were divided into two intervention groups: the BASYS (n = 10) and Balance Disc (BD; cushion type, n = 10). All participants underwent six supervised training sessions over a two-week period. Static postural control during single leg standing with closed eyes was assessed for the CAI limb. We collected COP data while participants balanced on the BASYS. The test was performed for 30 sec, and the total trajectory length and 95% ellipse area were calculated. In the assessment of dynamic postural stability, Y-Balance tests-anterior, posteromedial, and posterolateral directions were measured on the CAI limb for all participants and normalized to the individual's leg length. Participants were recorded at three instances: pretraining (Pre), post-training 1 (Post1: after the first training), and post-training 2 (Post2: after the last training).
There was an effect on time in the COP total trajectory length of the BASYS group, which was significantly decreased for Post 1 and Post 2 than for the Pre (p = 0.001, 0.0001). Group differences and time-by-group interactions were not observed for either of the Y-balance test reach distances.
The study's primary finding was that two weeks of intervention in the in-phase mode on the BASYS improved static postural control in participants with CAI.
Level Ⅰ, randomized control trial.
Background:
Pole vaulters and decathletes frequently experience several types of injuries to their lower back, often resulting in mechanical low back pain (LBP). However, the risk factors for the ...occurrence of LBP in these athletes have not been defined.
Purpose:
To determine the physical factors that relate to LBP occurrence for collegiate pole vaulters and decathletes.
Study Design:
Cohort study; Level of evidence, 2.
Methods:
We observed 31 pole vaulters and decathletes for 1 year. At the start of the observation period, isokinetic flexion and extension muscle strength of the knee and hip joints were recorded along with active and passive range of motion (ROM) and muscle tightness. Participants were then divided into 2 groups using the median value of each measurement: those below the median (low group) and those above the median (high group). The log-rank test was used to compare LBP occurrence between the low group and high group for all measurements. Multivariate regression analyses were thereafter applied using the Cox proportional hazards regression.
Results:
Log-rank tests revealed a statistically significant change in the survival curve for the occurrence of LBP in the participants with chronic LBP (P = .037), the low group for hip flexion peak torque per body weight on the non-takeoff leg (P = .047), and the low group for passive hip flexion angle on both legs (takeoff leg: P = .034; non-takeoff leg: P = .023). In addition, log-rank tests revealed a statistically significant change in the survival curve for the occurrence of LBP in the low group for passive hip extension angle on the takeoff leg only for the participants without chronic LBP (P = .014).
Conclusion:
It may be necessary to acquire sufficient ROM and hip flexion to prevent LBP occurrence in pole vaulters and decathletes.
Background:
Athletes participating in track and field jumping events (long jump, triple jump, high jump, and pole vault) are exposed to ground-reaction forces on the takeoff leg that are several ...times their body weight. This can cause injuries specific to such activities.
Purpose:
To determine the incidence of injuries in collegiate jumpers using the guidelines set forth by a 2014 consensus statement on injury surveillance during track and field events.
Study Design:
Descriptive epidemiology study.
Methods:
A total of 51 jumpers between April 2016 and March 2017 and 54 jumpers between April 2017 and March 2018 participated in this study. All athletes were from a single college in Japan. Baseline information on athletes participating in the long jump, triple jump, high jump, and pole vault was collected at study enrollment. Practice and competition exposures were reported by the team trainer. Injury incidence was calculated as the number of injuries per 1000 athlete-exposures (AEs).
Results:
A total of 147 injuries were reported among 16,998 exposures (8.65 injuries per 1000 AEs). The most common injury locations were the posterior thigh and lateral ankle (17.0%), followed by the posterior foot or toe (12.9%); the most frequent type of injury was strain/muscle rupture/tear (21.1%). The most common injury for long jumpers was ankle sprain (23.3%); for high jumpers, flexor hallucis longus tendinosis (15.8%); and for pole vaulters, hamstring strain (13.2%).
Conclusion:
The overall characteristics are different for each event; therefore, injuries for each event need to be investigated.
: To determine the difference in joint angles of the shoulder, hip, and trunk (angle of the upper torso and lower torso) during vaulting between male pole vaulters with and without chronic low back ...pain (LBP) and to examine the relationship between the range of motion (ROM) and maximum angle of the same joint during vaulting in all participants.
: This cross-sectional study included 17 male vaulters. The participants were divided into two groups (chronic LBP and control) based on their questionnaire results. Four high-speed cameras were used to record at 240 Hz from the touchdown of the last step on the run-up to the pole straight phase. The vaulter cleared the bungee bars that were set at 90% of their personal best record. The ROM of hip flexion and extension, shoulder flexion, and straight leg raise were measured.
: There was no difference in the joint angles between the chronic LBP group and control group. In contrast, there was a significantly positive correlation between ROM and the maximum joint angle during hip extension (p = 0.01, r = 0.58).
: Insufficient hip ROM may result in compensatory motion in lumbar extension during pole vaulting.
The low back is the most common injury location in pole vaulters, and low back pain (LBP) can easily become chronic. Therefore, knowing the physical characteristics of athletes experiencing repeated ...LBP may be beneficial for recovery and injury prevention.
The purpose of this study was to describe and analyze the physical characteristics of pole vaulters with chronic LBP.
A cross-sectional study.
Twenty male pole vaulters participated in this study. A questionnaire was used to garner descriptive and personal data, including personal best performance in the pole vault. Additionally, the following physical characteristics were measured: 1) isokinetic muscle strength of hip and knee flexors and extensors, 2) active/passive range of motion and muscle flexibility in multiple joints and regions, 3) performance on the Functional Movement Screen™ (FMS™) and 4) spinal column alignment. Subjects were categorized using the questionnaire and divided into two groups, one with and one without chronic LBP.
The personal best performance and angle on the active straight leg raise test (SLR) were significantly lower and smaller, respectively, in the chronic LBP group than in the non-chronic LBP group. Additionally, the difference between the passive SLR angle and active SLR angle (ΔSLR) was significantly larger in the chronic LBP group than in the non-chronic LBP group. Those with chronic LBP had were more likely to have a FMS™ composite score ≤14.
The active SLR angle and ΔSLR were significantly smaller and larger, respectively, in the chronic LBP group than in the non-chronic LBP group. This may be because of the poor stability of trunk or incompetence of the kinetic chain required for raising the lower limbs. The chronic LBP group had a significantly higher probability of having an FMS™ composite score of ≤14. it may be important to examine the active straight leg raise (vs. passive only), and fundamental movements as screened by the FMS ™ in pole vaulters.
2b.
BACKGROUND: Deadlift (DL) and back squat (BSQ) are considered different exercises because of their kinematic and kinetic characteristics. However, there are similarities, such as joint movement and ...the maximal muscle strength generated. Although there are differences and similarities, it is unclear which is more related to athletic performance. OBJECTIVE: This study aimed to determine the relationship between DL and jump, acceleration, and change of direction and compare whether DL or BSQ differ in their relationship to jumping, acceleration, and change of direction. METHODS: Eighty male volleyball players (age: 19.6 ± 0.9 years, height: 179.2 ± 6.7 cm, mass: 71.9 ± 9.4 kg) volunteered to participate in this study. Countermovement jump (CMJ), 10-m sprint, and 1–5 repetition maximum (1–5 RM) BSQ were measured on day 1. The T-test and 1–5 RM DL were measured on day 2. RESULTS: DL had a significant and moderate relationship with all parameters of CMJ (r= 0.328, p< 0.01), 10-m sprint (r=-0.471, p< 0.01), and T-test (r=-0.441, p< 0.01). BSQ showed a significant and moderate relationship with the 10-m sprint (r=-0.489, p< 0.01) and T-test (r=-0.356, p< 0.01), but a significant and weak relationship only with CMJ (r=- 0.289, p< 0.01). In addition, no significant differences were found in the comparison of correlation coefficients (p> 0.05). CONCLUSIONS: Deadlift may be introduced as an alternative exercise to BSQ when there are limitations in the training environment, such as the lack of a squat rack to safely perform BSQ or home confinement due to external factors like pandemics.
Background: Few descriptive epidemiological studies have investigated the prevalence and risk factors of hamstring strain injury in athletics. Objectives: To investigate the variations in the ...incidence of hamstring strain injury between seasons in track and field athletes, and further to investigate the relationship between environmental temperature and occurrence of hamstring strain injury. Methods: We recruited track and field athletes and recorded information about hamstring strain injuries between January 2013 and December 2016. Each year was divided into four seasons (March - May: early-season; June - August: mid-season; September - November: late-season, and December - February: off-season), and the incidence of hamstring strain injury in each season was calculated. The incidence rate ratio for each season was calculated according to the temperature of the day when an injury was recorded. Results: In total, 183 hamstring strain injuries were recorded (16.98/100 person-years). The incidence was significantly higher in early-season (IRR = 2.23) than in other seasons. The incidences in mid-and late-seasons (IRR= 0.64, and 0.57, respectively) were significantly lower than those in other seasons. The very-high-temperature zone showed a significantly lower incidence of hamstring strain injuries (IRR= 0.53) than did other temperature zones. The lower-middle-temperature zone showed a significantly higher incidence of hamstring strain injury (IRR = 1.46) than the other temperature zones. Conclusions: This study results suggest that hamstring strain injury is most likely to occur in early-season, possibly due to the low temperatures that characterize this season and the rapid increase of running speed required for subsequent competitions. Keywords: Periodization, Athletics, Injury Surveillance, High-Speed Running
In this study, we aimed to clarify the characteristics of neuromuscular function, kinetics, and kinematics of the lower extremity during sprinting in track and field athletes with a history of strain ...injury. Ten male college sprinters with a history of unilateral hamstring injury performed maximum effort sprint on an athletic track. The electromyographic (EMG) activity of the long head of the biceps femoris (BFlh) and gluteus maximus (Gmax) muscles and three-dimensional kinematic data were recorded. Bilateral comparisons were performed for the EMG activities, pelvic anterior tilt angle, hip and knee joint angles and torques, and the musculotendon length of BFlh. The activity of BFlh in the previously injured limb was significantly lower than that in the uninjured limb during the late-swing phase of sprinting (p < 0.05). However, the EMG activity of Gmax was not significantly different between the previously injured and uninjured limbs. Furthermore, during the late-swing phase, a significantly more flexed knee angle (p < 0.05) and a decrease in BFlh muscle length (p < 0.05) were noted in the injured limb. It was concluded that previously injured hamstring muscles demonstrate functional deficits during the late swing phase of sprinting in comparison with the uninjured contralateral muscles.
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