Abdominal Crunch Machine With Secondary-Arm Backrest Motion
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Solution Overview
Problem
Existing abdominal exercise machines fail to provide a natural rolling motion for the back during crunch exercises, often leading to strain and improper muscle engagement due to rigid bench surfaces and fixed axis rotations.
Innovation Solution
The seat and backrest of the exercise machine are rotationally attached to secondary arms, which are then connected to the frame via spaced axes of rotation, allowing for a more natural rolling motion and variable resistance through a translation bar and resistance mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the seat and backrest are rigidly attached to the frame with fixed axis rotation, then the structural stability is improved, but the natural rolling motion of the back during crunch exercises is restricted
Solution Approach 1:
The seat and backrest are divided into separate components, each capable of independent rotation about spaced axes. This segmentation allows the backrest to rotate independently to accommodate the natural rolling motion of the back during crunches, while the seat remains relatively stable, thus resolving the contradiction between structural stability and natural motion.
Solution Approach 2:
The attachment system transitions from a rigid fixed-axis rotation to a dynamic multi-axis rotation system. The spaced axes of rotation allow the backrest to adapt its orientation dynamically during the exercise motion, enabling the natural rolling motion of the back while maintaining structural stability through the constrained rotational paths.
2Stability of the object's composition
If a rigid bench surface is used, then the support stability is improved, but the strain on the back during crunch exercises increases
Solution Approach 1:
The backrest is designed with rotational freedom about spaced axes, allowing it to dynamically adapt to the user's back curvature during crunches. This dynamic adjustment reduces strain on the back by accommodating natural spinal rolling motion, while the overall structure remains stable due to the constrained rotational mechanism.
3Device complexity
If fixed axis rotation is used, then the mechanical simplicity is improved, but the exercise effectiveness for isolating abdominal muscles is reduced
Solution Approach 1:
The rotation system is segmented into multiple independent rotational axes rather than a single fixed axis. This segmentation allows the backrest to follow the natural curved path of the back during crunches, improving exercise effectiveness by properly isolating the abdominal muscles, while adding only moderate complexity to the mechanical structure.
Data Source
AI summary
An exercise machine, components of the exercise machine, and methods related to using the exercise machine that allow for a performance of an abdominal exercise which provides for a more natural rolling motion for a back of a user while providing variable resistance. Specifically, at least one of a seat or a backrest of the exercise machine, and preferably both, is not rotationally attached directly to a frame of the exercise machine, but is instead rotationally attached to a secondary arm of the exercise machine which is then rotationally attached to the frame.