... Characteristics and described results of the 55 included studies are provided in Table 2. Forty-one studies compared treadmill walking to indoor overground walking (Anders et al., 2019;Barela et al., 2019;Bechard et al., 2011;Bizovska et al., 2018;Carpinella et al., 2010;Chockalingam et al., 2006Chockalingam et al., , 2012Cronin & Finni, 2013;Damiano et al., 2011;Das Gupta et al., 2021;Dewig et al., 2022;Dingwell et al., 2001;Dufek & Bates, 1990;Fellin et al., 2016;Galloway et al., 2021;Hall et al., 2004;Hollman et al., 2016aHollman et al., , 2016bHutchinson et al., 2021;Lee & Hidler, 2008;Lim & Lee, 2018;Martin & Li, 2017;Matsas et al., 2000;Montes et al., 2019;Montgomery et al., 2016;Murray et al., 1985;Nagano et al., 2013;Nymark et al., 2005;Park et al., 2022;Parvataneni et al., 2009;Pearce et al., 1983;Prosser et al., 2011;Ralston, 1960;Riley et al., 2007;Ryu et al., 2018;Stolze et al., 1997;Strathy et al., 1983;Strutzenberger et al., 2022;Vickery-Howe et al., 2021;White et al., 1998;Wrightson et al., 2020;Yngve et al., 2003), five studies compared treadmill walking to outdoor overground walking (Barnett et al., 2015;Custance, 1970;Daniels et al., 1953;Shi et al., 2019;Wyndham et al., 1971), and nine studies did not clearly describe the overground surface (Cronin & Finni, 2013;Fallahtafti et al., 2021;Fullenkamp et al., 2018;Hossain et al., 2022;Khademi-Kalantari et al., 2017;Korvas et al., 2013;Mazaheri et al., 2016;Mileti et al., 2020;Tong et al., 2020 Murray et al., 1985;Riley et al., 2007;Stolze et al., 1997;Strutzenberger et al., 2022) and four studies included the addition of carried external load (Custance, 1970;Daniels et al., 1953;Fellin et al., 2016;Vickery-Howe et al., 2021), whereas 15 studies did not report walking speed (Chockalingam et al., 2012;Damiano et al., 2011;Dingwell et al., 2001;Fellin et al., 2016;Hossain et al., 2022;Hutchinson et al., 2021;Khademi-Kalantari et al., 2017;Lee & Hidler, 2008;Lim & Lee, 2018;Mazaheri et al., 2016;Montes et al., 2019;Nymark et al., 2005;Shi et al., 2019;Strathy et al., 1983;Tong et al., 2020). The results of Downs and Black quality assessment scores are presented in Table 3. ...