OBJECTIVE:To establish reference values for isometric strength of 12 muscle groups and flexibility of 13 joint movements in 1,000 children and adults and investigate the influence of demographic and ...anthropometric factors.
METHODS:A standardized reliable protocol of hand-held and fixed dynamometry for isometric strength of ankle, knee, hip, elbow, and shoulder musculature as well as goniometry for flexibility of the ankle, knee, hip, elbow, shoulder, and cervical spine was performed in an observational study investigating 1,000 healthy male and female participants aged 3–101 years. Correlation and multiple regression analyses were performed to identify factors independently associated with strength and flexibility of children, adolescents, adults, and older adults.
RESULTS:Normative reference values of 25 strength and flexibility measures were generated. Strong linear correlations between age and strength were identified in the first 2 decades of life. Muscle strength significantly decreased with age in older adults. Regression modeling identified increasing height as the most significant predictor of strength in children, higher body mass in adolescents, and male sex in adults and older adults. Joint flexibility gradually decreased with age, with little sex difference. Waist circumference was a significant predictor of variability in joint flexibility in adolescents, adults, and older adults.
CONCLUSIONS:Reference values and associated age- and sex-stratified z scores generated from this study can be used to determine the presence and extent of impairments associated with neuromuscular and other neurologic disorders, monitor disease progression over time in natural history studies, and evaluate the effect of new treatments in clinical trials.
Background
Not all anterior cruciate ligament (ACL) injuries are preventable. While some ACL injuries are unavoidable such as those resulting from a tackle, others that occur in non-contact ...situations like twisting and turning in the absence of external contact might be more preventable. Because ACL injuries commonly occur in team ball-sports that involve jumping, landing and cutting manoeuvres, accurate information about the epidemiology of non-contact ACL injuries in these sports is needed to quantify their extent and burden to guide resource allocation for risk-reduction efforts.
Objective
To synthesize the evidence on the incidence and proportion of non-contact to total ACL injuries by sex, age, sport, participation level and exposure type in team ball-sports.
Methods
Six databases (MEDLINE, EMBASE, Web of Science, CINAHL, Scopus and SPORTDiscus) were searched from inception to July 2021. Cohort studies of team ball-sports reporting number of knee injuries as a function of exposure and injury mechanism were included.
Results
Forty-five studies covering 13 team ball-sports were included. The overall proportion of non-contact to total ACL injuries was 55% (95% CI 48–62,
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2
= 82%; females: 63%, 95% CI 53–71,
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2
= 84%; males: 50%, 95% CI 42–58,
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2
= 86%). The overall incidence of non-contact ACL injuries was 0.07 per 1000 player-hours (95% CI 0.05–0.10,
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= 77%), and 0.05 per 1000 player-exposures (95% CI 0.03–0.07,
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= 97%). Injury incidence was higher in female athletes (0.14 per 1000 player-hours, 95% CI 0.10–0.19,
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= 40%) than male athletes (0.05 per 1000 player-hours, 95% CI 0.03–0.07,
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= 48%), and this difference was significant. Injury incidence during competition was higher (0.48 per 1000 player-hours, 95% CI 0.32–0.72,
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= 77%; 0.32 per 1000 player-exposures, 95% CI 0.15–0.70,
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2
= 96%) than during training (0.04 per 1000 player-hours, 95% CI 0.02–0.07,
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= 63%; 0.02 per 1000 player-exposures, 95% CI 0.01–0.05,
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= 86%) and these differences were significant. Heterogeneity across studies was generally high.
Conclusion
This study quantifies several key epidemiological findings for ACL injuries in team ball-sports. Non-contact ACL injuries represented over half of all ACL injuries sustained. The proportion of non-contact to total ACL injuries and injury incidence were higher in female than in male athletes. Injuries mostly occurred in competition settings.
To determine the maximal isometric neck strength of male and female rugby and football (soccer) athletes, and to investigate the relationship between neck strength and sport played, sex, age, ...anthropometric measurements and concussion history.
Cross-sectional observational study.
In total, 358 (70% male) healthy football and rugby playing adolescents and adults participated. Isometric neck strength and anthropometry measurements were collected, as well as completion of a sociodemographic survey. The mean (standard deviation) of all measurements for each age group was calculated and compared between sports and sexes, with correlation analyses performed to determine associations between all variables.
In general, rugby athletes had stronger neck musculature compared to football athletes, and males had stronger neck musculature compared to age-matched females, with these strength differences becoming increasingly significant with age (p < 0.05). The athletes with stronger neck muscles were older, taller, heavier, had higher bilateral grip strength and larger neck girth compared to those with weaker neck muscles (p < 0.05). Male rugby athletes who self-reported higher rates of a previous concussion had lower neck flexor/extensor strength ratio (p < 0.01). In 11-12-year-old male footballers, increased heading was associated with increased self-reported previous concussion (p < 0.01).
These normative neck strength data can form important reference values for rugby and football athletes from adolescence into adulthood. Male rugby athletes with a previous history of concussion demonstrated strength imbalances of their neck musculature (lower flexor/extensor ratio), with this finding having potentially important implications for training protocols and injury prevention initiatives.
Proximal phalangeal fractures are one of the most commonly treated hand injuries in children. Conservative management of these fractures is often to splint for 5 weeks post injury, despite children ...presenting as clinically healed at 3 weeks post injury. Therefore, we investigated the effect of splinting for only 3 weeks in children who present with clinically healed proximal phalangeal fractures at 3 weeks compared with usual care.
Participants (n=80, aged 10.3 ±2.5 years) presenting to the Hand Clinic of a tertiary Children's Hospital in Sydney, Australia, were randomly allocated into a Current Protocol and a New Protocol group. Following were the inclusion criteria: aged between 5 and 16 years; present with an non-displaced or minimally displaced and stable fracture; no surgical intervention; assessed as clinically healed at 3-week visit. The primary outcome measure was total active motion (TAM) of the injured digit compared with the contralateral digit (deg), at 5 weeks post injury. Secondary outcome measures were grip strength, and a parent-reported questionnaire. Statistical analysis used χ 2 test and the absolute difference described by a 90% CI. The New Protocol was considered noninferior if the 90% CI overlap was > 20% of the Current Protocol. Analysis was by intention to treat.
There was a 10% loss to follow up at 5 weeks (Current Protocol =4, New Protocol =4). All CIs between groups overlapped by >10%. TAM 90% CI for Current Protocol was 17.7 to 5.4 degrees and for the New Protocol was 4.7 to 1.6 degrees.
A change in practice is warranted to cease immobilization for children with conservatively managed proximal phalangeal fractures who present as clinically healed at 3 weeks. Therapist assessment of fracture healing is an appropriate indicator for intervention and can be utilized in a therapist-led model of care.
Level 1-noninferiority randomized control trial with 2 parallel arms.
•Whole of life spatiotemporal and pressure data were generated from 1000 individuals.•Gait speed was similar in adolescents and adults, and in children and older adults.•Peak pressure was highest ...under the rearfoot in children and forefoot in adolescents and adults.•Peak pressures under forefoot and whole foot increased with age and were greatest in older adults.
The purpose of this study was to establish normative reference values for spatiotemporal and plantar pressure parameters, and to investigate the influence of demographic, anthropometric and physical characteristics.
In 1000 healthy males and females aged 3–101 years, spatiotemporal and plantar pressure data were collected barefoot with the Zeno™ walkway and Emed® platform. Correlograms were developed to visualise the relationships between widely reported spatiotemporal and pressure variables with demographic (age, gender), anthropometric (height, mass, waist circumference) and physical characteristics (ankle strength, ankle range of motion, vibration perception) in children aged 3–9 years, adolescents aged 10–19 years, adults aged 20–59 years and older adults aged over 60 years.
A comprehensive catalogue of 31 spatiotemporal and pressure variables were generated from 1000 healthy individuals. The key findings were that gait velocity was stable during adolescence and adulthood, while children and older adults walked at a comparable slower speed. Peak pressures increased during childhood to older adulthood. Children demonstrated highest peak pressures beneath the rearfoot whilst adolescents, adults and older adults demonstrated highest pressures at the forefoot. Main factors influencing spatiotemporal and pressure parameters were: increased age, height, body mass and waist circumference, as well as ankle dorsiflexion and plantarflexion strength.
This study has established whole of life normative reference values of widely used spatiotemporal and plantar pressure parameters, and revealed changes to be expected across the lifespan.
To investigate the injury characteristics and insurance cost of anterior cruciate ligament injuries in sub-elite football players in New South Wales, Australia.
Descriptive epidemiological study.
...Three years of insurance records (2018–2020) was used to describe anterior cruciate ligament injury costs and characteristics. Concomitant injuries and the mechanism of injury were determined by analysing the injury descriptions. Claim characteristics and costs are presented by age group (junior = 7–17 years, senior = 18–34 years, and veteran = 35 + years) and sex. Categorical data (including age-groups and sex) are presented as counts and percentages and analysed using a Chi squared or Fisher’s exact test. Cost data are reported as means ± standard deviation with 95 % confidence intervals.
Over the course of three football seasons (2018–2020), 786 anterior cruciate ligament injuries were reported to the injury insurance company. The total insurance cost was AU$3,614,742 with direct injury insurance costs accounting for 36.3 % of the total costs. The mean indirect insurance costs were six-fold higher than direct insurance costs (AU$11,458 vs AU$1914). Isolated injuries had an average cost of $4466 whilst concomitant injuries had an average cost of $4951. Surgical costs are excluded from direct cost calculations. The peak injury count occurred in the first month of all three football seasons, immediately after the pre-season.
Anterior cruciate ligament injuries represent a substantial economic burden to the insurer and individual. The cost data provided can be used for future economic and modelling studies.
Muscle strength is routinely measured in patients with neuromuscular disorders by hand-held dynamometry incorporating a wireless load cell to evaluate disease severity and therapeutic efficacy, with ...magnitude of effect often based on normative reference values. While several hand-held dynamometers exist, their interchangeability is unknown which limits the utility of normative data. We investigated the variability between six commercially available dynamometers for measuring the isometric muscle strength of four muscle groups in thirty healthy individuals. Following electro-mechanical sensor calibration against knowns loads, Citec, Nicholas, MicroFET2, and Commander dynamometers were used to assess the strength of ankle dorsiflexors, hip internal rotators, and shoulder external rotators. Citec, Jamar Plus, and Baseline Hydraulic dynamometers were used to capture hand grip strength. Variability between dynamometers was represented as percent differences and statistical significance was calculated with one-way repeated measures ANOVA. Percent differences between dynamometers ranged from 0.2% to 16%. No significant differences were recorded between the Citec, Nicholas, and MicroFET2 dynamometers (
> 0.05). Citec grip strength measures differed to the Jamar Plus and Baseline Hydraulic dynamometers (
< 0.01). However, when controlling for grip circumference, they were comparable (
> 0.05). Several hand-held dynamometers can be used interchangeably to measure upper and lower limb strength, thereby maximising the use of normative reference values.
Higher neck strength has been postulated to reduce head impact magnitude during purposeful heading in football.
This pilot trial explored the effect of a neck exercise programme on (1) neck strength ...and (2) head impact magnitude during heading in male and female adolescent football players.
Boys and girls (aged 12-17 years) were randomised by team to the intervention (5 weeks of supervised neuromuscular neck exercises integrated into part 2 of the FIFA 11 + , completed three times per week) or the control group (usual part 2 of the FIFA 11 + , no neck exercises). Outcomes included isometric neck strength and head impact magnitude (peak linear acceleration and peak angular velocity) during standardised heading from a throw-in (at baseline and 6 weeks) plus completion of an evaluation survey by intervention players and coaches.
In total, 52 players (n = 31 intervention; n = 21 control) completed the study. Mixed-model analysis of variance (ANOVA) revealed significant differences in neck strength variables (p < 0.001), peak linear acceleration (p = 0.04) and peak angular velocity (p = 0.04) between the intervention and control groups over time. Intervention players demonstrated increases in mean composite neck strength (53.8% intervention vs 15.6% control) as well as decreases in mean peak linear head acceleration during heading (- 11.8% vs - 5.0%) from baseline to follow-up. Reduction in peak angular velocity was more pronounced in girls (- 27.7%) than boys (- 11.5%) in the intervention group. The addition of neck exercises into part 2 of the FIFA 11 + was feasible and accepted by players and coaches.
On average, players who completed neck exercises demonstrated an increase in isometric neck strength and a decrease in head impact magnitude during heading. These exercises were easily incorporated into usual training. Australian New Zealand Clinical Trials Registry (no: ACTRN12619001375145).
Inertial Measurement Units (IMUs) are promising alternatives to laboratory-based motion capture methods in biomechanical assessment of athletic movements. The aim of this study was to investigate the ...validity of an IMU system for determining knee and trunk kinematics during landing and cutting tasks for clinical and research applications in sporting populations. Twenty-seven participants performed five cutting and landing tasks while being recorded using a gold-standard optoelectronic motion capture system and an IMU system. Intra-class coefficients, Pearson’s r, root-mean-square error (RMSE), bias, and Bland-Altman limits of agreements between the motion capture and IMU systems were quantified for knee and trunk sagittal- and frontal-plane range-of-motion (ROM) and peak angles. Our results indicate that IMU validity was task-, joint-, and plane-dependent. Based on good-to-excellent (ICC) correlation, reasonable accuracy (RMSE < 5°), bias within 2°, and limits of agreements within 10°, we recommend the use of this IMU system for knee sagittal-plane ROM estimations during cutting, trunk sagittal-plane peak angle estimation during the double-leg landing task, trunk sagittal-plane ROM estimation for almost all tasks, and trunk frontal-plane peak angle estimation for the right single-leg landing task. Due to poor comparisons with the optoelectronic system, we do not recommend this IMU system for knee frontal-plane kinematic estimations.
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