A flexible battery system for wearable and robotic applications comprises rigid or semi-rigid battery cells interconnected by flexible interconnection sections that enable conformability to curved contours while maintaining electrical connectivity. Each flexible interconnection section includes a flexible substrate with embedded conductive elements such as conductive traces, wires, or accordion-folded materials. The system includes a protective encapsulation layer and the battery cells may be arranged in linear, circular, or matrix configurations, including auxetic patterns for enhanced three-dimensional conformability.

A protective pad assembly for removably positioning on an arm or a leg of a user of the protective pad assembly for protecting an elbow or a knee of the user. The protective pad assembly comprises an outer protective unit including a protective cushion pad configured to protect the elbow or the knee of the user from impact, and a self-retaining device mounted to the outer protective unit for retaining the outer protective unit on the arm or leg of the user. The self-retaining device includes a resilient retaining split-ring clamp having two opposite free ends spaced from one another. The free ends of the resilient retaining split-ring clamp are circumferentially expandable or contractable relative to one another for retaining the protective pad on an arm or a leg of the user of the protective pad assembly over one of the elbow and the knee thereof.

A kneepad device includes an outer cover having a curved body and including two or more protrusions positioned along, and extending away from, an inner surface of the curved body. The kneepad also includes an inner cushion configured to couple with the outer cover and contact a knee of a user when being worn. The outer cover has a hardness that is greater than that of the cushion, such that the outer cover provides a protective shell, and the inner cushion conforms to the surface of the user's knee. When coupled, the outer cover and inner cushion define an air pocket therebetween, which reduces the localized pressure exerted on the user's knee when kneeling. The two or more protrusions can define elongate strips of material, the space between which further defines the air pocket between the cover and the cushion.

A protective torso assembly to be worn by a player engaged in a contact sport, includes an outer protective member assembly including left and right front chest members having upper recessed segments and left and right arch members having frontal portions coupled to the chest members by flexible couplers such that said frontal portions overlie the upper recessed segments. When the protective torso assembly is in a neutral state, a first reference point of the frontal portion of the left arch member is positioned a first distance from a second reference point of the recessed segment of the left chest member. Additional embodiments of a protective torso assembly are disclosed having components and/or assemblies selected from a plurality of components and/or a plurality of assemblies based upon player data.