Table 2. Data extraction of the included publications.

Author, publication year, and country	Study aim and design	Study setting and population	Measurement and results
Adams et al (2018), Australia [29]	Aim: Whether playground design facilitated different levels of PA and FMS Design: Cross-sectional	Setting: Neighborhood (3 playgrounds in 1 city; traditional, adventure, contemporary). Population: 57 children, 5–10 yrs.	Measurement: SOFIT (modified) Results: There were no significant associations with FMS between the three playgrounds. The most frequent performed FMS were locomotor skills (31.3%), specifically walking (18.3%) and running (11.3%). Body management skills (15.2%) and climbing (12.3%) was also observed at all three playgrounds, whereas object control skills such as catching and throwing were rarely observed (0.0–0.2%) Children performed few FMS but used a wider variety of equipment in the contemporary and adventure playgrounds.
Famelia et al (2018), Indonesia [35]	Aim: Relationships among FMS, playground PA, and gender Design: Cross-sectional	Setting: 4 ECEC centers (2 urban—2 rural) Population: 66 children, 3–6 yrs.	Measurement: PMSC + the Test of Gross Motor Development-3 Results: No main effect of location for locomotor skills and perceived movement skill competence.
Fjørtoft (2001), Norway [30]	Aim: How playing in the natural environment might stimulate FMS Design: Intervention (play in forest versus traditional playground 1–2 hours/day for 9 months)	Setting: 3 ECEC centers (1 experimental—2 control) Population: 75 children, 5–7 yrs. (46 in the experimental group)	Measurement: EUROFIT + Beam walking and Indian skip Results: At the posttest 9 months after the pretest, significant differences were found in eight out of nine FMS test items in the experimental group (flamingo balance (p<0.001), plate tapping (p<0.001), standing broad jump (p<0.001), bent arm hang (p<0.001), Indian skip (p<0.001), sit-ups (p<0.01), beam walking (p<0.01), and shuttle run (p<0.01)) whereas the control group experienced a significant difference in three test items (standing broad jump (p<0.01), bent arm hang (p<0.001), and Indian skip (p<0.001). At the pretest the experimental group scored lower than the control group, but scored better in all test items at the posttest
Foweather et al (2021), England [21]	Aim: The association between play behavior and FMS during recess at preschool Design: Cross-sectional	Setting: 12 ECEC centers Population: 133 children, 3–5 yrs.	Measurement: Video-assessment using CMSP Results: Relative to time spent in other types of play behaviors, time spent in play without equipment was positively associated with total FMS and locomotor skills, while time spent in locomotion activities (moving while not engaged in an active play game) was negatively associated with total FMS and locomotor skills
Gil-Madrona et al (2019), Spain [37]	Aim: The contribution of public playgrounds to obesity reduction, motor, social, and creative development Design: Cross-sectional	Setting: Neighborhood (41 parks in 1 city) Population: 1019 adults	Measurement: Survey Results: 53.7% parents agreed with the positive contribution of public playgrounds to motor skills (38% quite agree and 15.7% totally agree).
Grunseit et al (2020), Australia [28]	Aim: Relationship between school playground size and PA, fitness, and FMS Design: Cross-sectional	Setting: 43 primary schools Population: 5238 children, 5–12 yrs.	Measurement: Scoring of 7 FMS skills Results: No association between playground space and motor skills.
Loftesnes (2021), Norway [31]	Aim: Evaluating a new-built nature playground for children aged 2–6 years Design: Cross-sectional post-intervention study (A nature playground used in one year for min. 2 days a week)	Setting: 9 ECEC centers Population: 30 adults (18 staff + 12 parents)	Measurement: Survey and interview Results: Parents found their child being more able to cope with motor skills.
Miller et al (2017), USA [27]	Aim: Quantify equipment/areas impacted for children with sensory challenges Design: Cross-sectional	Setting: Child rehabilitation center (1 playground) Population: 181 children, 3–15 yrs. (41 with special needs)	Measurement: Coding of camera recordings Results: The behavior most often observed across all pieces of equipment was novel use, ranging from 41.82–97.66% of the time. Least = Mobius, most = sand and water. Motor planning was highest for the Mobius Climber (58.18%) and lowest for sand and water.
Nobre et al (2023), Brazil [36]	Aim: factors associated with FMS in preschoolers from a Brazilian urban area Design: Cross-sectional	Setting: 9 ECEC centers Population: 211 children, 3–5 yrs.	Measurement: TGMD-2 Results: Children from ECEC centers with a park or courtyard had significant higher locomotion skills than those who did not have outdoor spaces in the ECEC center.
Szeszulski et al (2022), USA [25]	Aim: Association between the characteristics of the ECEC center environment and FMS Design: Cross-sectional	Setting: 16 ECEC centers Population: 172 children, 3–5 yrs.	Measurement: CMSP Results: Better outdoor play environment quality score and more outdoor equipment were positively associated with higher CMSP scores.
Tortella et al (2016), Italy [32]	Aim: Effects of structured and unstructured activities played at the playground on FMS Design: Intervention (10 weeks– 1 hour/week—half structured and half unstructured play at specific playground)	Setting: Neighborhood (1 playground) Population: 110 children, 5 yrs. (71 in the experimental group)	Measurement: Scoring of 9 FMS skills (3 for fine and 6 for gross motor skills) Results: The experimental group improved significantly in 4 out of 6 gross motor tasks (putting a medicine ball (p<0.001), one leg balance on left foot (p<0.05), balance on beam (p<0.001), and balance on platform (p<0.001)) and in none of the fine motor tasks.
Tortella et al (2022), Italy [33]	Aim: Effects of partly structured activities or free play on FMS Design: Intervention (10 weeks– 1 hour/week–partly structured versus free play at specific playground)	Setting: Neighborhood (1 playground) Population: 141 children, 4–6 yrs. (62 in experimental group 1; partly structured, 43 in experimental group 2; free play, 36 in control group)	Measurement: MABC-2 + TCM + Balance on Elastic Platforms Task and Balance on Beam Task Results: No significant difference in motor competence measured by the TCM or the MABC-2 between groups. A significant improvement was found in the Platforms Task and Balance on Beam Task in the partly structured activity group compared to the free play and control groups.
True et al (2017), USA [26]	Aim: The contribution of various preschool environmental characteristics to children’s FMS Design: Cross-sectional	Setting: 22 ECEC centers (4 head start, 7 faith-based, 11 commercial) Population: 229 children, 3–5 yrs.	Measurement: CMSP Results: Playground size is a significant predictor of total motor score (effect size 0.33) when adjusting the analyses for other significant predictors, e.g., age, classroom size, teacher education and electronic media use but not locomotor score and object control score, individually. Time spent in outdoor open spaces, fixed and portable playground equipment were non-significant predictors to total gross motor scores.
Virji-Babul et al (2006), Canada [34]	Aim: Analyzing the level of motor engagement within the playground Design: Cross-sectional	Setting: 1 Child rehabilitation center Population: 6 children with DS, 6–7 yrs.	Measurement: Coding of camera recordings Results: Children spent a great amount of time in motor-based activities (90%) in a playground setting. The primary motor activity was swinging. The tasks appeared to become more difficult as the environment became more complex (even surface versus grass and incline surface).

CMSP = the Champs Motor Skill Protocol; DS = Downs syndrome; ECEC = Early childhood education and care; EUROFIT = European Test of Physical Fitness, the Motor Fitness Test; FMS = fundamental movement skills; MABC-2 = Movement Assessment Battery for Children; PA = physical activity; PMSC = Pictorial Scale of Perceived Movement Skill Competence; yrs. = years; SOFIT = System for Observing Fitness Instruction Time; TGMD-2 = Test of Gross Motor Development; TMC = Test of Motor Competence.