Reference values of hip abductor torque among youth athletes: Influence of age, sex and sports

Normal hip strength and range of motion values in youth and adult female national football teams: Data from 504 assessments

OBJECTIVES

To determine normal hip adduction- and abduction strength and range of motion (ROM) values for youth and adult female national team football players, and evaluate if increasing age, playing position and leg dominance were associated with these strength and ROM values.

DESIGN

Cohort study.

SETTING

National football center.

PARTICIPANTS

344 unique asymptomatic female football players.

MAIN OUTCOME MEASURES

Hip internal/external rotation (°), Bent Knee Fall Out test (cm), hip adduction/abduction strength(N) and ratio, and normalised hip adduction/abduction torque (Nm/kg).

RESULTS

A total of 504 assessments were performed. A total of 107 players underwent two (n = 67), three (n = 27) or four (n = 13) assessments. Mean peak hip adduction strength was 39% greater in 20 + Y old players 170 (±53 N) than in 13Y old players 122 (±28 N). Normalised hip adduction torque was 9% greater: 2.5 (±0.8Nm/kg) versus 2.3 (±0.5Nm/kg). A positive association between age and all strength measurements was found, while a negative association between age and hip external rotation and total hip rotation was found. No clinically relevant differences were found for the associations between playing position, leg dominance and hip strength- and ROM values.

CONCLUSION

Normal values for hip strength and range of motion in youth and adult female national football players are presented that can be used as clinical reference values.

Functional capacity and risk of injury in CrossFit practitioners measured through smartphone apps

BACKGROUND

CrossFit is a high intensity functional training that tends to challenge physical limits. The objectives of this study were to assess functional capacity, prevalence and risk of injury in CrossFit practitioners.

METHODS

This cross-sectional, observational and prospective study evaluate the rate of injuries that occurred in CrossFit practitioners in the last 12 months and their functional capacities. The sample was given for convenience, with a total of 22 participants. Functional capacities and risk of injury were measured by functional tests using PHAST and Clinometer applications. The prevalence of injuries was cataloged using the Nordic Musculoskeletal Questionnaire.

RESULTS

5% of the injuries occurred in the neck; 9% in shoulder, hip, thighs, ankles and feet; 14% in the lumbar spine and knees. The worst functional results were for the shoulder medial rotation ROM test, where 86-95% of the athletes were classified as "Bad"; the dorsiflexion ROM test also performed poorly in 68% of athletes.

CONCLUSION

This study shows that the CrossFit practice suggests that the injury prevalence is relatively low, affecting mainly knees, lumbar spine, wrists and hands. However, the risk of injuries shown by the functional musculoskeletal assessment is higher, especially in the shoulder and ankle, and it is important for the practitioner to realize a specific functional assessment before starting training.

Association Between Protocols of the Sit-to-Stand Test and Lower Limb Muscle Force Output in Patients on Hemodialysis and Subjects Without Chronic Kidney Disease

OBJECTIVE

To evaluate the association of three protocols of the sit-to-stand (STS) test with muscle force output of knee extension (KE) and knee flexion (KF) in patients on hemodialysis and subjects without chronic kidney disease.

METHODS

This cross-sectional study included a hemodialysis group [n = 60, 59.5 (16.8) years, 55% female] and a control group [n = 60, 43.0 (11.8) years, 50% female]. The assessments were performed in 2 days, and the participants were submitted to three protocols of STS test (5-repetition STS, 10-repetition STS and 30-s STS) or muscle force output of the KE and KF evaluation by handheld dynamometer based on randomization.

RESULTS

The hemodialysis group presented reduced muscle force output of the KE and KF, a longer time to perform the 5 STS and 10 STS tests, and a lower number of repetitions in the 30-s STS test. The three STS tests were associated with muscle force output of the KE in the hemodialysis group, in which the 10-repetition STS test showed the best association (R² = 0.47; adjusted R² = 0.42). However, the only association between the STS test and muscle force output of the KE in the control group was found in the 10-repetition STS test (R² = 0.20; adjusted R² = 0.13).

CONCLUSIONS

The three protocols of STS tests were associated with muscle force output of the KE in patients on hemodialysis. However, the 10-repetition STS test was the best protocol to estimate the quadriceps muscle torque in these patients.

Hip external rotation isometric torque for soccer, basketball, and volleyball athletes: normative data and asymmetry index

BACKGROUND

Deficits in strength of the hip external rotators (ER) affect trunk, hip, and knee movement patterns, potentially contributing to injury in athletes.

OBJECTIVES

To provide normative data on isometric torque for hip ER in athletes of three distinct sports and to determine if isometric torque for the hip ER and torque asymmetry between legs differ among sports and between sexes.

METHODS

Basketball, soccer, and volleyball athletes (n=451) were evaluated. Hip ER torque was quantified bilaterally with athletes in prone and 90° of knee flexion using a hand-held dynamometer.

RESULTS

Data are expressed as mean and 95% confidence interval. Hip ER torque values in Nm/kg for the dominant and non-dominant limbs were, respectively, 0.46 (0.44, 0.48) and 0.42 (0.40, 0.44) for male soccer athletes; 0.35 (0.32, 0.37) and 0.27 (0.25, 0.29) for male basketball athletes; and 0.37 (0.34, 0.39) and 0.35 (0.32, 0.37) for male volleyball athletes. Hip ER torque in Nm/kg for the female volleyball athletes was 0.29 (0.26, 0.33) for the dominant and 0.29 (0.25, 0.32) for the non-dominant limb. The Limb Symmetry Index for male soccer, basketball, and volleyball players was, respectively, 94% (91, 97), 81% (75, 87), and 95% (91, 99). For female volleyball players the Limb Asymmetry Index was 102% (95, 108). Male volleyball athletes showed higher torque values than female volleyball athletes.

CONCLUSIONS

This study reported normative values for hip ER isometric torque of youth athletes. Clinicians can use the reported data as reference to identify torque deficits in athletes of the three reported sports.

Meeting movement quantity or quality return to sport criteria is associated with reduced second ACL injury rate

The purposes of this prospective cohort study were (1) to assess if second anterior cruciate ligament (ACL) injury rate 2 years after ACL reconstruction (ACLR) in those who returned to pivoting sport was associated with meeting (a) quantitative return to sport (RTS) criteria, (b) qualitative RTS criteria, and (c) combined quantitative and qualitative RTS criteria, and (2) to determine why athletes did not return to their preinjury (level of) sport. Athletes after ACLR performed RTS tests immediately before RTS: seven movement quantity (strength and hop test battery) and two movement quality (countermovement jump with LESS score and hop-and-hold test) tests. A 2-year postoperative questionnaire asked for RTS, reasons for not returning to the same (level of) sport and second ACL injuries. One hundred and forty-four athletes (82%) completed the questionnaire and 97 of them returned to a pivoting sport. Seven of these athletes had a second ACL injury. Meeting the hop test battery RTS criterion (absolute risk reduction 11%; p = .047) and hop-and-hold test RTS criterion (absolute risk reduction 15%; p = .031) were both significantly associated with a reduced second ACL injury rate. Meeting combined RTS criteria were not significantly associated with second ACL injury rate. Therefore, RTS tests after ACLR should at least comprise a hop test battery or the hop-and-hold test to reduce second ACL injury risk after return to pivoting sport. Also, one-third of all athletes mentioned fear of reinjury as the main reason for not returning to their preinjury (level of) sport. This psychological component should be taken seriously and discussed during rehabilitation.

Physical Performance Measures of Flexibility, Hip Strength, Lower Limb Power, and Trunk Endurance in Healthy Navy Cadets: Normative Data and Differences Between Sex and Limb Dominance

ABSTRACT

Lopes, TJA, Simic, M, Alves, DdS, Bunn, PdS, Rodrigues, AI, Terra, BdS, Lima, MdS, Ribeiro, FM, Vilão, P, and Pappas, E. Physical performance measures of flexibility, hip strength, lower limb power, and trunk endurance in healthy navy cadets: Normative data and differences between sex and limb dominance. J Strength Cond Res 35(2): 458-464, 2021-The objectives were to provide normative data on commonly used physical performance tests that may be associated with musculoskeletal injuries in Navy cadets and assess for sex and limb dominance differences. A large cohort of Navy cadets were assessed for physical performance tests of flexibility (ankle dorsiflexion range of motion and sit and reach), isometric hip strength, lower limb power (single-leg hop), and trunk endurance (plank and side plank tests). Besides providing normative data tables, sex and limb dominance differences were assessed by a 2-way mixed analysis of variance. A total of 545 Brazilian Navy cadets (394 men) representing 79% of the cadets in the Academy participated. Normative reference values were reported as mean ± SD, 95% confidence interval and percentiles. For tests of muscle strength, power, and endurance, men performed better than women (p < 0.001). For flexibility tests, women achieved greater distances than men for the sit and reach test (p < 0.001), but no difference for ankle dorsiflexion (p = 0.51). Overall, there were no clinically relevant differences between limbs. In conclusion, normative data for commonly used physical performance tests were provided. Although no clinically relevant side-to-side differences were found, men presented higher values for lower limb strength and power, as well as trunk endurance than women, whereas women demonstrated increased flexibility. Valuable normative data are provided to professionals who work with young, active populations from the injury prevention or rehabilitation perspective because the current study may help professionals to identify athletes or cadets whose performance is outside the normative values and may be at risk for injury.

LESS THAN HALF OF ACL-RECONSTRUCTED ATHLETES ARE CLEARED FOR RETURN TO PLAY BASED ON PRACTICE GUIDELINE CRITERIA: RESULTS FROM A PROSPECTIVE COHORT STUDY

Background

A recently published Dutch practice guideline emphasizes criterion-based rehabilitation after anterior cruciate ligament reconstruction (ACLR) instead of time-based. As a consequence of this criterion-based rehabilitation, return to play is only suggested when athletes meet specific return to play (RTP) criteria.

Purpose

The goal of this prospective observational study was to analyze if physical therapists adhere to ACLR practice guideline RTP criteria for testing and return to sport decisions, and to explore whether there is a difference in adherence between physical therapists specialized in sports versus those who are not.

Methods

When the treating physical therapist cleared an athlete for RTP after ACLR, the primary researcher performed RTP measurements according to the ACLR practice guideline to investigate if all nine quantitative and qualitative RTP criteria were met.

Results

Of the 158 athletes (54 females and 104 males, mean age 24 ± 6 years, 12 ± 3 months after surgery), 69 (44%) had performed the RTP measurements with their primary physical therapist. Of the athletes tested by their primary physical therapist 23% met all RTP criteria compared to 10% of the athletes who were not tested at all by their primary physical therapist (p = 0.026). Of the athletes rehabilitating with a sports physical therapist, 52% had been tested by their primary physical therapist compared to 34% of the athletes rehabilitating with a non-sports physical therapist (p = 0.024).

Conclusion

Only 44% of the athletes were tested according to the guideline RTP criteria and only 23% of them were given an RTP advice consistent with the ACLR guideline. Although sports physical therapists adhered to the guideline more often than non-sports physical therapists, the adherence is still alarmingly low. More attention for the implementation of ACLR guidelines and RTP criteria is needed.

Level of evidence

Therapy, level 2b.

Hip-Muscle Activity in Men and Women During Resisted Side Stepping With Different Band Positions

CONTEXT

Weakness or decreased activation of the hip abductors and external rotators has been associated with lower extremity injury, especially in females. Resisted side stepping is commonly used to address hip weakness. Whereas multiple variations of this exercise are used clinically, few data exist regarding which variations to select.

OBJECTIVE

To investigate differences in muscle-activation and movement patterns and determine kinematic and limb-specific differences between men and women during resisted side stepping with 3 resistive-band positions.

DESIGN

Controlled laboratory study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 22 healthy adults (11 men, 11 women; age = 22.8 ± 3.0 years, height = 171.6 ± 10.7 cm, mass = 68.5 ± 11.8 kg).

INTERVENTION(S)

Participants side stepped with the resistive band at 3 locations (knees, ankles, feet).

MAIN OUTCOME MEASURE(S)

We collected surface electromyography of the gluteus maximus, gluteus medius, and tensor fascia lata (TFL) for the moving and stance limbs during the concentric and eccentric phases. We also measured trunk inclination, hip and knee flexion, and hip-abduction excursion.

RESULTS

Hip-abductor activity was higher in women than in men ( P ≤ .04). The pattern of TFL activity in the stance limb differed by sex. Women performed the exercise in greater forward trunk inclination ( P = .009) and had greater hip excursion ( P = .003). Gluteus maximus and medius activity increased when the band was moved from the knees to the ankles and from the ankles to the feet, whereas TFL activity increased only when the band was moved from the knees to the ankles. Findings were similar for both the stance and moving limbs, but the magnitudes of the changes differed.

CONCLUSIONS

Compared with placing the band around the ankles, placing the band around the feet for resisted side stepping elicited more activity in the gluteal muscles without increasing TFL activity. This band placement is most appropriate when the therapeutic goal is to activate the muscles that resist hip adduction and internal rotation.

Isometric muscle strength in children and adolescents using Handheld dynamometry: reliability and normative data for the Brazilian population

OBJECTIVE

Isometric muscle strength measured by Handheld dynamometer indicates physical ability. There is no normative data for the Brazilian population. This study aims (a) to describe the development of isometric muscle strength in healthy children and adolescents 5-15 years of age; (b) to evaluate Handheld dynamometer inter and intra-rater reliability.

METHODS

Isometric muscle strength was obtained for shoulder abduction, elbow and knee flexion and extension, dorsiflexion and plantar flexion in 55 boys and 55 girls, aged between 5 and 15 years. Inter-rater reliability was determined based on the evaluation of 2 raters, with a 20-min interval between them. Intra-rater reliability was based on 2 evaluations from the same rater, one week apart. Interclass correlation coefficient (ICC_{2,1; 3,1}), Bland Altman plots and linear regression models with mixed effects were used to quantify inter and intra-rater reliability, agreement and associations with physical activity level and maturational factors.

RESULTS

A linear development of isometric muscular strength was observed for ages between 5 and 10. After age 10, boys showed a larger isometric muscular strength, when compared to girls. Both inter and intra-rater measurements of the Handheld dynamometer are reliable (ICC>0.63).

CONCLUSIONS

This study shows increase in isometric muscle strength starting at 10 years of age for boys, when compared to girls and inter and intra-rater reliability for the assessment of isometric strength, using the Handheld dynamometer for the muscle groups tested on the dominant and non-dominant side, for children between 5 and 15 years of age.