Aspects of Validity of the Single Leg Squat Test: A Cohort Study of Female Soccer Players.

Movement screening tests to identify deficits or poor movement quality is commonly used in soccer and other sports to assess injury, to evaluate rehabilitation goals and return to sport after injury.

Female soccer players have an increased risk of suffering a knee injury which can be related to a poor knee control. Knee control can be observed and assessed by the Single Leg Squat (SLS) test. The SLS test is reported to be reliable, but there still is an overall lack of clear evidence of the accuracy for tests used for assessing movement quality in sports medicine, and the discriminate and predictive validity of the SLS test in a female soccer cohort needs to be further investigated. It is also not clear what significance other physiological- psychosocial- and hormonal factors have for the outcome of the SLS and for injury.

The overall aim of this project is to investigate if the outcome of a visually assessed SLS test can discriminate between individuals with a previous injury in the lower extremity, and if the outcome, separate or together with physiological-, psychosocial- and hormonal factors can predict future injury in a cohort of female soccer players.

The authors hypothesises that the outcome of the SLS cannot discriminate between individuals with a previous injury in the lower extremity but that the outcome of the SLS, separate or together with physiological-, psychosocial- and hormonal factors can predict future injury in a cohort of female soccer players.

269 female soccer players (≥16 Yr.) from Damallsvenskan, Elitettan and division 1 in the area of Stockholm was enrolled in the study and baseline measurements were done during 2022-01-08 to 2022-02-21. The female soccer cohort will be followed during the season 2022 regarding injuries upcoming injuries.

Study Overview

• Status: Completed
• Conditions: Reproducibility of Results; Functional Movement Disorders; Sports Medicine
• Intervention / Treatment: Other: No intervention

Detailed Description

Movement screening tests to identify deficits or poor movement quality is commonly used in soccer and other sports to assess injury, to evaluate rehabilitation goals and return to sport after injury.

Female soccer players have an increased risk of suffering a knee injury which can be related to a poor knee control. Knee control can be observed and assessed by the Single Leg Squat (SLS) test which is one of the most commonly used clinical tests for assessing movement quality of the knee and other parts of the kinetic chain. The SLS test is reported to be reliable, but there still is an overall lack of clear evidence of the accuracy for tests used for assessing movement quality in sports medicine, and the discriminate and predictive validity of the SLS test in a female soccer cohort needs to be further investigated.

It is also not clear what significance physiological factors such as the range of ankle dorsi flexion, hip strength and psychosocial factors such as sleep, stress, anxiety and fear of avoidance have for the outcome of the SLS and for injury. Neither has hormonal factors such as self-assessed menstrual cycle, related factors and use of oral contraceptives been clarified regarding its significance in relation to the outcome of the SLS test and injury.

The overall aim of this project is to investigate if the outcome of a visually assessed SLS test can discriminate between individuals with a previous injury in the lower extremity, and if the outcome, separate or together with physiological-, psychosocial- and hormonal factors can predict future injury in a cohort of female soccer players.

• How is the outcome of a SLS test and its separate items associated to physical factors.
• Are the outcome of a SLS test and its separate items able to discriminate between players with and without previous injury in the lower extremity.
• Are the outcome of a SLS test, separate, or together with physical- (hip strength, ankle mobility), psychosocial- (stress, sleep, anxiety, fear of avoidance) and hormonal (self-assessed menstrual cycle, related factors and use of oral contraceptives) factors able to predict injury in the lower extremity measured every four weeks for10 months following the baseline measurements.

The authors hypothesises that the outcome of the SLS cannot discriminate between individuals with a previous injury in the lower extremity but that the outcome of the SLS, separate or together with physiological-, psychosocial- and hormonal factors can predict future injury in a cohort of female soccer players.

Twenty soccer teams from Damallsvenskan, Elitettan and division 1 in the area of Stockholm was contacted in order to recruit at least 200 female soccer players (≥16 Yr.). During autumn 2021 information about the study was sent out to the clubs by e-mail, and for those who wanted to participate, further written and verbal information was given. Before baseline assessment, which started 2022-01-08, information about the project was given verbally and in writing to the soccer players. Baseline assessment included physical assessments as well as psychosocial-, hormonal-, previous injury- and demographic questionnaires. Inclusion criteria was female soccer players contracted with a club in Damallsvenskan, Elitettan or division 1 for the season 2022 who was 16 years or older, and native in written and spoken Swedish. Exclusion was an ongoing injury in the lower extremity that made it impossible to perform the physical baseline assessments, or that the performance may present an additional risk for injury. The physical tests were performed at the local club by the doctoral student John Ressman. The time needed for baseline measurements per participant including physical tests and self-assessed questionnaires was approximately 15-20 minutes. In order to follow up on injuries during the soccer season 2022 a web-based questionnaire, the Oslo Sports Trauma Research Centre (OSTRC), was used. OSTRC is validated and designed to capture both injuries and overuse injuries in sports injury epidemiology. The web-based questionnaire will be sent via SurveyMonkey © every four weeks for 10 month following the baseline measurement.

• Study Type: Observational
• Enrollment (Actual): 269

Contacts and Locations

Study Locations

• Sweden
  • Huddinge, Sweden, 141 83
    • Karolinska Institutet

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Female soccer players contracted with a club in Damallsvenskan, Elitettan or division 1 for the season 2022.

Description

Inclusion Criteria:

• Female soccer players contracted with a club in Damallsvenskan, Elitettan or division 1 for the season 2022.
• Native in written and spoken Swedish.
• 16 years ol

Exclusion Criteria:

• Ongoing injury in the lower extremity that made it impossible to perform the physical baseline assessments, or that the performance may present an additional risk for injury

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Female soccer cohort; A female soccer cohort will be followed for 10 month regarding injuries	Other: No intervention; No intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Injury	Receiving an injury: time-loss or overuse	10 month
The Single Leg Squat	Fail/pass of the Single Leg squat	Cross sectional at baseline

Collaborators and Investigators

• Sponsor: Karolinska Institutet
• Investigators: Principal Investigator: Eva Rasmussen Barr, Karolinska Institutet. Alfred Nobels Allé 23, 141 83 Huddinge

Study record dates

Study Major Dates

• Study Start (Actual): January 8, 2022
• Primary Completion (Actual): December 21, 2022
• Study Completion (Actual): December 21, 2022

Study Registration Dates

• First Submitted: March 13, 2022
• First Submitted That Met QC Criteria: March 13, 2022
• First Posted (Actual): March 21, 2022

Study Record Updates

• Last Update Posted (Actual): December 13, 2023
• Last Update Submitted That Met QC Criteria: December 12, 2023
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Keywords: Sports Injury; The Single Leg Squat; Discriminative validity; Female Soccer players
• Additional Relevant MeSH Terms: Mental Disorders; Central Nervous System Diseases; Nervous System Diseases; Personality Disorders; Somatoform Disorders; Histrionic Personality Disorder; Movement Disorders; Conversion Disorder; Hysteria
• Other Study ID Numbers: Dnr 2021-05398-02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The datasets generated and/or analysed during the current study are not publicly available due to ethical regulation at the Karolinska Institute but are available from the corresponding author on reasonable request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No