Internal Risk Factors for Low Back Pain in Pole Vaulters and Decathletes: A Prospective Study.

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.

THE RELATIONSHIP BETWEEN CHRONIC LOW BACK PAIN AND PHYSICAL FACTORS IN COLLEGIATE POLE VAULTERS: A CROSS-SECTIONAL STUDY.

BACKGROUND: 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. PURPOSE: The purpose of this study was to describe and analyze the physical characteristics of pole vaulters with chronic LBP. STUDY DESIGN: A cross-sectional study. METHODS: 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. RESULTS: 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. CONCLUSION: 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. LEVEL OF EVIDENCE: 2b.

Hamstring muscles' function deficit during overground sprinting in track and field athletes with a history of strain injury.

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.

The Risk Factors of Hamstring Strain Injury Induced by High-Speed Running.

Hamstring strain injury is a multifactorial and complex problem involving interactions among various factors. Information about risk factors for this injury is inconsistent among studies because the strong effects of confounding factors and injury situations are often ignored. We investigated the relationship between hamstring strain induced by high-speed running and intrinsic risk factors, including hip muscle morphology and function, by excluding the influences of confounding factors. Sixty-one male track and field athletes (age, 19.6 ± 1.1 years; 95% confidence interval, 19.3-19.9) who often performed high-speed running were monitored throughout one season. Before the season, we measured hip and knee strength, muscle thickness of the gluteus maximus and biceps femoris, and hip and knee joint range of motion (ROM). We also obtained information about each athlete's history of hamstring injury by questionnaire. Eighteen athletes sustained hamstring strain injuries induced by high-speed running. Eighteen uninjured athletes who had the same profile of confounding factors as the injured athletes were selected as controls. Previously injured athletes had a significantly higher injury rate than uninjured athletes (p < .05; odds ratio, 2.85). No other measurements had a significant relationship with the occurrence of injury. However, passive hip ROM (flexion and extension) tended to be larger in the injured than control group. A history of hamstring strain was a strong risk factor for hamstring strain injury, and it may affect other factors. Therefore, the risk factors for hamstring strain injury should be investigated by eliminating the impact of a history of hamstring strain.