## 1 Introduction  
Sound muscle flexibility is a critical issue in athletic settings, and it determines the athletic performance of the lower-limb biomechanics [1]. In recent years, the floss band (FB) has been popularized by authors [PERSON] and [PERSON], who claim that the FB can increase range of motion (ROM), strength, and jumping performance and can enhance fatigue recovery [2,3]. The FB can be applied on a joint and on soft tissue. The FB technique consists of tightly wrapping part of a limb or a joint with a thick elastic band, resulting in fractional vascular occlusion of the blood flow distal to the wrapped area [4]. The reperfusion effect, fascial shearing, and occlusion of blood to the muscle may be the physiological mechanisms that underlie flossing [5]. When FB intervention involves passive twisting with the FB and active functional movements with a joint or muscle tightly wrapped by the FB for approximately 2-5 min, this technique could produce a localized effect of vascular occlusion and blood flow restriction and affect the relationship of the fascia with the neuromusculoskeletal system; this effect allows the fascia to stretch and move freely [5]. When the FB is loosened and the pressure is released, blood quickly flows back to the oppressed site, and this return of blood flow may increase localized microenvironmental changes, such as growth hormone levels and the catecholamine response; this blood flow may also increase muscle strength and muscle contraction efficiency [6, 7, 8, 9]. Moreover, studies have indicated that this process may increase the ROM of the joints. Therefore, pressure may be employed with the FB to compress the soft tissue to achieve the ischemic effect on the tissue [10,11]; subsequently, actions and stretches must be used to treat the localized part, remove the adhesion, allow the myofasical connective tissue to slide, and then restore the original muscle elasticity [11].  
Despite a lack of empirical evidence, tissue flossing is widely performed among athletes because of its immediate benefits. According to a scoping review, floss band use likely can enhance joint ROM but with a small to moderate effect on ankle, calf, thigh, and shoulder ROM [12,13]. The FB may be similar to blood flow restriction (BFR), but it is known to be used more frequently in warmups for promising outcomes [14]. [PERSON] et al. discovered that an FB could increase the ankle dorsiflexion angle by 6%, weight-bearing lunge value by 14%, and single-leg jump velocity by 6% in recreational athletes, which are all significant changes [15]. [PERSON] et al. indicated that an FB applied to the ankle is an effective method to increase ankle ROM [16]. [PERSON] et al. demonstrated that an FB used on hamstring muscles is more beneficial than dynamic stretching with respect to increasing hamstring muscle flexibility in healthy young men [5]. By contrast, another crossover study by [PERSON] indicated limited support for the use of an FB to improve ankle ROM, countermovement jumping, and sprinting performance up to 30 min postapplication in elite rugby union athletes.  
The effectiveness of flossing remains inconclusive. A recent systematic review and meta-analysis published by [PERSON] and [PERSON] focused on changes of ankle dorsiflexion using FB, but they did not investigate other outcome variables such as balance, muscle force output, or functional tests [17]. Taken together, substantial research on FB has been emerging, but the literature on FB effectiveness in knee joint ROM and athletic performance has yet to be evaluated, particularly in the knee joint in adults. To understand the effectiveness behind the FB, the objectives of this study were to investigate the effects of an FB on the flexibility of the quadriceps and hamstrings, knee proprioception, dynamic balance, and maximal muscle force output in recreationally active men.