# Could Mini-Trampoline Training Be Considered as a New Strategy to Reduce Asymmetries?
## 1 Introduction  
The inter-limb asymmetry or inter-limb imbalance describes the concept of comparing the function (i.e., strength, balance) of a limb respect to the other [1]. Recently, the inter-limb asymmetry concept has been fully investigated, with inconsistent findings, particularly related to physical health and sporting performances [1]. Asymmetries between legs are influenced by several factors such as lateral dominance (left vs. right), injuries and sport specificity [2, 3, 4]. In particular, leg dominance is an important factor both in sports and in everyday tasks [5]. It leads to an increase in asymmetry magnitude and can contribute to the development of injuries, thus influencing sport and everyday tasks [6]. The type of activity in which the athlete is engaged and the training volume of sport exposure influence the magnitude of asymmetry [3, 7]. In fact, team-sport athletes exhibit significantly greater inter-limb asymmetries values with respect to non-athlete, due to the large number of unilateral actions such as jumping and changes in direction [2, 7].  
In this context, training programs should be structured aiming to eliminate or limit the asymmetries in order to avoid negative effects on health and performances of athletes and non-athletes on the long-term. Previous research demonstrated how training strategies,such as balance training, resistance training and warm-up programs, could minimize inter-limb asymmetries and the relative risk of injuries [4,8,9]. Furthermore, studies show that by polymetric training could contribute to improve several sports/physical domains as vertical jump performance, acceleration, leg strength, muscular power and postural control [10,11]. Among the different pyometric training modalities, an effective method is represented by mini-trampoline training as it has been shown to increase lower body strength, bipodalic static and dynamic balance, and coordination in young subjects [12, 13, 14]. Among the mini-trampoline activities, in 2009, the American fitness teacher [PERSON] developed the SuperJump(r) training (SJ) comprising aerobic and anaerobic exercises alternating upper and lower limbs performed to the rhythm of music. SJ training facilitates the reduction in body mass (\(-\)5%) and fat mass (\(-\)7%), the improvement of the lipid profile with the reduction in low-density lipoprotein (\(-\)28%), and the reduction in bone resorption (\(+\)34%) and parathyroid hormone (\(-\)23%) [15,16]. Despite the beneficial acute and chronic effects of SJ on several physical outcomes, no study has yet investigated its acute effects on dynamic balance performances and balance inter-limb asymmetries in young subjects. Therefore, this study aimed to evaluate the acute effects of SJ training on dynamic balance performance and Bilateral Asymmetry (BA) and Unilateral Asymmetry (UA) Indexes in healthy young adults. Based on the positive effects of SJ on health-related domains, it could be hypothesized that SJ training might represent a good strategy in reducing dynamic BA and UA Indexes, providing an enjoyable and alternative training modality for both subjects and health specialists and/or coaches.