Hip Strength Disparities in College Soccer Players: Implications for Injury Risk and Conditioning Practices

The Y-balance Test (YBT) has been used to identify potential risk factors associated with lower extremity injuries (LEI), while mobility and strength assessments are often used to monitor progress following an injury. PURPOSE: This study aimed to explore differences in YBT scores along with lower body mobility and strength in Division I male soccer players who have reported a LEI in the last 12 months (LEI-Y) compared those without reported injuries (LEI-N). METHODS: Twenty-eight male soccer players (age: 20.7 ± 1.8 y; height: 183.8 ± 7.1 cm; mass: 78.5 ± 6.7 kg) completed pre-season evaluations which included YBT, hip strength, hamstring flexibility, and hip and ankle range of motion (ROM). All players were cleared for testing by the head athletic trainer and team physician and had no current LEI precluding them from participating. However, players self-reported if they had experienced a lower extremity injury or surgery in the prior twelve months. Hip adduction and abduction strength was evaluated using a dynamometer and calculated relative to body weight. Hip and ankle ROM were measured using a goniometer, and hamstring flexibility was measured using the sit-and-reach test. The YBT scores and leg length were used to determine a composite score for each leg. Data was presented as means ± standard deviations. RESULTS: For LEI-N, there were no notable imbalances in right to left side comparisons for hip adduction strength (44.8 ± 6.8 vs 43.5 ± 7.5 %) or hip abduction strength (49.2 ± 5.3 vs 49.0 ± 9.1 %). In the LEI-Y group, there was a discernible difference between the right and left side for hip adduction strength (43.7 ± 7.8 vs 41.4 ± 6.1 %) and hip abduction strength (48.4 ± 8.3 vs 45.1 ± 6.3 %). Relative hip strength and ankle ROM scores were also lower overall in the LEI-Y group compared to the LEI-N group, but no such trends were observed for YBT composite scores, hip ROM, or hamstring flexibility. CONCLUSION: The findings of this study indicate that the LEI-Y group had greater bilateral imbalance in lower limb strength, lower hip strength, and lower ankle ROM scores compared with those without injury history. Future research is recommended to evaluate the impact of injury on these markers and examine their associations with future injury risk

Pelvic Tilt Disparities and Lower Extremity Strength and Mobility Differences in Collegiate Wrestlers

ABSTRACT The presence of excessive anterior pelvic tilt (PT) prior to performing loaded structural movements such as a squat or deadlift may be detrimental. However the ability to move from a neutral spine into a slight anterior PT during these movements may be beneficial for postural control, but this capability and relationship to hip function is under-represented in the literature. PURPOSE: The purpose of this study was to determine the relationship between the ability to move into an anterior PT, hip and hamstring range of motion (ROM), hip strength, and y-balance test (YBT) scores in Division I wrestlers. METHODS: Twenty-two collegiate wrestlers completed a PT test, YBT, hip and hamstring ROM, and hip strength tests during pre-season after clearance by the team physician. Wrestlers were divided into: 1) those that could perform an anterior PT without compensation (PT-N; n = 11; age 19.7 ± 1.6 y; height: 175.3 ± 8.4 cm; mass: 79.4 ± 26.1 kg), and 2) those showing mobility or stability concerns during the PT test (PT-C; n = 11; age 19.6 ± 1.7 y; height: 176.5 ± 4.6 cm; mass: 73.8 ± 10.4 kg). Total hip ROM on the right (R) and left (L) was measured by summing internal and external rotation measured using a goniometer. Hip adduction and abduction strength was measured using a dynamometer, and calculated relative to body weight. The standardized YBT approach included measures of leg length to determine a composite score for both legs. Hamstring ROM was measured using the sit-and-reach test (SRT). Data were recorded using mean ± standard deviations. RESULTS: PT-N had higher total ROM than PT-C in the R hip (78.2 ± 11.1o vs 74.1 ± 8.8 o), L hip (72.9 ± 10.8 o vs 71.5 ± 8.8o), and SRT scores (39.4 ± 4.3 cm vs 33.5 ± 8.3 cm). PT-N had greater relative strength than PT-C for R hip adduction (44.6 ± 10.5 vs 40.7 ± 11.1 kg), L hip adduction (42.5 ± 9.7 vs 39.1 ± 11.8 kg), and L hip abduction (40.3 ± 14.3 vs 36.0 ± 6.8 kg), however these differences were muted relative to body weight. PT-N had higher composite YBT scores on the R leg (95.2 ± 8.5 vs 92.4 ± 4.8 %) and L leg (97.1 ± 9.1 vs 90.9 ± 4.4 %). CONCLUSION: In collegiate wrestlers sufficient hip mobility, motor control, and hip symmetry may be related to optimal postural control at the hip when flexing under heavy load. Further research with a larger sample size and baseline measures of PT is recommended to examine these trends in more detail

Force Plate Determined Jump Height, Braking Symmetry, and Reactive Strength Index in Collegiate Athletes

Many athletes are required to perform high intensity (HI) movements unilaterally and bilaterally. Force plate technology can measure is capable of quantifying performance during HI movements, such as vertical jump (VJ), as well as any asymmetries involved in the movement, but limited data using this modality is currently available. PURPOSE: The purpose of this study is to present descriptive data of VJ height, left and right leg braking symmetry (L/R-S), and modified reactive strength index (mRSI) during a no-hand countermovement VJ (CMJ) measured using a force plate on male (M) and female (F) Division I athletes. METHODS: Forty-nine M lacrosse players (MLAX; age: 20.0 ± 1.6 y; height: 182.0 ± 6.3 cm), 28 F lacrosse players (WLAX; age: 19.5 ± 1.6 y; height: 165.7 ± 3.8 cm), 31 M baseball players (BB; age: 20.0 ± 1.7 y; height: 183.1 ± 9.8 cm), 19 F softball players (SB; age: 19.7 ± 1.6 y; height: 169.8 ± 7.0 cm), 7 M tennis players (MTN; age: 20.6 ± 1.5 y; height: 181.8 ± 8.9 cm), and 11 F tennis players (FTN; age: 20.1 ± 1.3 y; height: 163.7 ± 8.9 cm), completed a no-hands countermovement VJ test on a force plate system. Jump height, L/R-S (0 being symmetrical, negative values indicate more force applied through the right foot and more positive indicates the same for the left foot), and mRSI were recorded using mean ± standard deviation. VJ testing was conducted during pre-season following physician clearance. RESULTS: VJ height for M was highest in BB (40.2 ± 7.3 cm) and lowest in MTN (33.8 ± 3.9 cm). VJ height for F was highest in SB (26.3 ± 4.3 cm) and lowest in WTN (23.3 ± 5.3 cm). The largest discrimination between L/R-S was seen for M in BB (-5.5 ± 13.9) with the smallest in MLAX (-1.29 ± 14.45). For F the largest L/R-S was seen in WTN (-2.86 ± 15.34) and the smallest in SB (0.44 ± 7.09). BB had the highest mRSI (0.50 ± 0.08) and MTN had the lowest (0.36 ± 0.12) in M. SB had the highest mRSI in F (0.36 ± 0.05) with WTN showing the smallest (0.29 ± 0.15). CONCLUSION: The differences seen in VJ data between sports and gender may be explained by the specific demands placed on the body during competition. This data may be able to provide strength and conditioning coaches and other sports medicine professionals insight into common trends related to explosive power and L/R-S in each sport to provide more specialized training to address potential asymmetries and target VJ goals

Lower Extremity Injury and Y-Balance Scores in Division I Women’s Soccer

The Y-Balance Test (YBT) is a functional, portable assessment used to examine stability and mobility in the lower extremities (LE). However descriptive YBT data and how scores may compare across healthy and previously injured women’s soccer players is scarce but in demand. PURPOSE: The purpose of this study was to explore the difference in YBT scores in female collegiate-level soccer athletes with and without a recent history of LE injury. METHODS: Twenty-two Division I female soccer players completed a YBT during pre-season. All of the subjects were cleared for testing by the head athletic trainer and the team physician and had no current LE injury precluding them from participating. Players were also asked to self-report if they had experienced a lower extremity injury or surgery in the prior twelve months, which divided the sample into two groups – those who did report having a LE injury in the past 12 months (LEI; n = 13, age = 19.9 ± 1.4 y, height = 166.9 ± 6.9 cm) and those who did not (LEI-N; n = 9, age = 19.8 ± 1.7 y, height = 169.2 ± 7.9 cm). Standardized approaches were used for the YBT to obtain scores for all three directions (anterior, posterior medial, posterior lateral) for both legs, along with the measurement of right and left leg length to determine a composite score for both legs. Descriptive statistics were calculated as mean ± standard deviation. RESULTS: The LEI group had a lower YBT composite score compared to the LEI-N group on the left side (86.0 ± 26.6 vs 90.04 ± 9.1 %) and the right side (85.2 ± 26.4 vs 87.2 ± 8.0 %). CONCLUSION: YBT screening during pre-season may help identify ongoing imbalances in soccer players with a prior LE injury, even after they have been cleared to practice or condition by the sports medicine team. However, ongoing research is needed comparing YBT scores prior to the injury to further support the use of the YBT in this manner

Strength and Mobility Measures in Division I Female Volleyball Student Athletes Across Different Positions

Shoulder internal and external rotation and hand grip measures are commonly used to evaluate upper extremity mobility and strength in college athletes. However, positional differences and their impact on these scores are rarely considered, therefore further research is needed in sports such as volleyball where information on these potential trends is lacking. PURPOSE: The purpose of this study was to identify possible differences between strength and mobility measures in female volleyball student-athletes whose responsibilities include hitting (predominantly overhead roles) versus those who are primarily passers and diggers (non-overhead roles). METHODS: Thirteen Division I volleyball student-athletes who volunteered to participate in this study were divided into two groups - hitters (H; age = 19.6 ± 1.5 y, height = 180.7 ± 6.7 cm) and passers (P; age = 19.3 ± 1.2 y, height = 172.0 ± 10.0 cm). Players were tested on their shoulder range of motion (ROM) for internal rotation (IR), external rotation (ER), and flexion using a goniometer. Total ROM was identified as a sum of IR and ER. Hand grip strength was measured in the dominant hand using a hand grip dynamometer. All testing was completed by certified healthcare professionals prior to preseason following clearance by the team physician. Descriptive statistics were calculated as mean ± standard deviations. RESULTS: H had higher total ROM than P in both the right arm (158.6 ± 65.8° vs 144.1 ± 65.8°) and left arm (165.0 ± 67.8° vs 155.7 ± 69.7°). H had higher flexion than P in the right, dominant arm (176.9 ± 7.9° vs 171.5 ± 18.7°), but similar flexion in the left, nondominant arm (180.1 ± 5.6° vs 180.7 ± 3.4°). H and P both had higher than average values for shoulder ROM compared to published normative data. Hand grip strength was also higher in H compared to P (31.6 ± 6.2 kg vs 26.1 ± 2.5 kg). CONCLUSIONS: H displayed greater total ROM in both arms, a higher flexion ROM in their dominant arm than P as well as greater strength in their dominant arm. This emphasizes the importance of mobility and strength in their positional demands, and the need for shoulder stability. This information provides strength and conditioning coaches preliminary information on possible foci for training and areas where further research is still needed

Relationship Between the Y-Balance Test and Lower Extremity Strength and Mobility in Collegiate Lacrosse Players

Lacrosse players must make quick directional changes, often on one leg while under force. This demands strength, mobility, and motor control throughout the kinetic chain. The Y-Balance test (YBT) has been used to gauge motor control in athletes. Still, more research on the relationship between the YBT and lower extremity (LE) mobility and strength in lacrosse players is needed. PURPOSE: The purpose of this study was to examine the relationship between YBT scores, hip range of motion (ROM), ankle dorsiflexion, hip abduction (ABD) and adduction (ADD) strength, and passive and active thoracic rotation in male college lacrosse players. METHODS: Fifty Division I male lacrosse players (age: 20 ± 1.6 y; height: 182.0 ± 6.3 cm; weight: 83.2 ± 6.0 kg) performed a YBT including measures of leg length to determine a composite score for the right and left leg (YBT-R and YBT-L, respectively). Thoracic spine active rotation (TS-AR), passive rotation (TS-PR), and range of motion (ROM) at the hip (sum of internal and external rotation) for each limb was measured with a goniometer. Ankle dorsiflexion was assessed using a clinometer instrument. Hip abduction (ABD) and adduction (ADD) strength was measured using a dynamometer and calculated relative to body weight. Hamstring flexibility was measured using the sit-and-reach test. All players were cleared for testing by the team physician and had no current LE injury precluding them from participating. Descriptive statistics were calculated as mean ± standard deviation and Pearson product-moment correlation coefficients were calculated. The level of significance was set at p \u3c 0.05. RESULTS: YBT-R (but not YBT-L) was significantly correlated with TS-AR to the right and left (r = 0.41 and r = 0.31, p \u3c 0.05), and with the sit-and-reach test (r = 0.28, p \u3c 0.05). Both YBT-R and YBT-L were significantly correlated with hip ROM on the right only but with both right and left ankle dorsiflexion (p \u3c 0.05). CONCLUSIONS: YBT scores on the right and left side were related to thoracic spine, hip, and ankle mobility, but not to hip ADD and ABD strength in collegiate male lacrosse players. Hip rotation measures could reflect capabilities for single-leg balance, stability, and proprioception and could improve YBT performance, however further research incorporating alternative LE strength measures is recommended

Lower Extremity Strength and Mobility in Division I Male Basketball Players Across Vertical Jump Performance

Vertical jump (VJ) performance is a commonly used assessment to measure explosive muscular power in collegiate strength and power athletes such as basketball players. However, research on the relationship between VJ performance and measures of lower extremity (LE) strength and mobility is inconsistent. PURPOSE: The purpose of this study was to analyze hip and ankle strength and mobility measures among collegiate male basketball players by comparing those with higher and lower VJ performance. METHODS: During pre-season screening, ten Division I male basketball players were assessed to determine VJ height by completing a countermovement VJ test. Players were divided into two groups based on VJ performance which were comprised of the top 5 performers (T; 20.8 ± 2.0 years, 186.4 ± 7.4 cm, 79.6 ± 8.6 kg; VJ: 70.4 ± 6.9 cm) and the bottom 5 performers (B; 20.0 ± 1.6 years, 197.4 ± 9.9 cm, 94.2.6 ± 19.7 kg; VJ: 56.9 ± 2.5 cm). Hip range of motion (ROM) was measured with a goniometer, and total hip ROM was calculated as the sum of internal and external rotation for each limb. Ankle dorsiflexion was assessed using a clinometer instrument. Hip abduction (ABD) and adduction (ADD) strength was measured using a dynamometer, and calculated relative to body weight. Players also self-reported LE injuries in the prior 12 months. Descriptive statistics were calculated as mean ± standard deviation. RESULTS: Compared to B, T had lower left leg hip ROM (69.4 ± 6.6° vs 72.6 ± 7.5°). T had higher right leg hip ROM (73.4 ± 5.0° vs 70.0 ± 11.9°) and left/right ankle ROM (36.8 ± 4.1° vs 33.2 ± 3.0° and 35.4 ± 2.4° vs 32.8 ± 4.0°, respectively). T had higher relative right/left leg ABD strength (43.5 ± 6.3 vs 37.5 ± 10.9 % and 37.8 ± 7.1 vs 36.8 ± 11.8 %, respectively), and right/left leg ADD strength (44.0 ± 21.4 vs 40.9 ± 6.1 % and 41.2 ± 10.5 vs 39.5 ± 12.3 %, respectively). However, only 20% of the T group compared to 60% of the B group reported experiencing a recent LE injury. CONCLUSION: Although the T group had higher right leg hip ROM, ankle ROM, and greater hip strength these were just trends, making it difficult to draw any inferences about the association between hip and ankle strength and mobility measures on VJ performance. It is also possible that the greater presence of recent LE injury in the B group may have impacted the findings of this study

The SUMup collaborative database: Surface mass balance, subsurface temperature and density measurements from the Greenland and Antarctic ice sheets (1912 - 2023)

The SUMup database is a compilation of surface mass balance (SMB), subsurface temperature and density measurements from the Greenland and Antarctic ice sheets. This 2023 release contains 4 490 442 data points: 1 778 540 SMB measurements, 2 706 413 density measurements and 5 489 subsurface temperature measurements. This is respectively 1 477 132, 420 825 and 4 715 additional observations of SMB, density and temperature compared to the 2022 release. This new release provides not only snow accumulation on ice sheets, like its predecessors, but all types of SMB measurements, including from ablation areas. On the other hand, snow depth on sea ice is discontinued, but can still be found in the previous releases. The data files are provided in both CSV and NetCDF format and contain, for each measurement, the following metadata: latitude, longitude, elevation, timestamp, method, reference of the data source and, when applicable, the name of the measurement group it belongs to (core name for SMB, profile name for density, station name for temperature). Data users are encouraged to cite all the original data sources that are being used. Issues about this release as well as suggestions of datasets to be added in next releases can be done on a dedicated user forum: https://github.com/SUMup-database/SUMup-data-suggestion/issues. Example scripts to use the SUMup 2023 files are made available on our script repository: https://github.com/SUMup-database/SUMup-example-scripts