Establishing the association between comfortable riding posture and rider’s physical attributes (anthropometry and ROM measurements):
From the literature survey, it is evident that the earlier researchers studied the relationship between comfortable posture (in terms of comfort joint angles) and anthropometry of the occupant (rider or driver) in two/ four wheeler context (Park et al., 2019, 2000; Porter and Gyi, 1998). It is also noticed that none of them attempted to establish the association between CRP and rider’s anthropometric and ROM variables. Thus, the association study of motorcyclist’s CRP with anthropometric and ROM characteristics, using stepwise multiple linear regression is some new addition in knowledge-base. Result of the present research also included the intra and inter correlations between CRP and rider’s physical characteristics (anthropometry and ROM) by mentioning the strength and direction of the relationships.
Establishing the association between motorcycles attributes (comfortable riding position) and rider’s physical attributes (anthropometry and ROM measurements):
Reported researches are available regarding association between anthropometry and riding/
driving position in case of bi-cycle and car (Fatollahzadeh, 2006; Park et al., 2019, 2000; Porter and Gyi, 1998) From the literature survey, it is evident that none of the earlier researchers attempted to establish the association between comfortable riding position (RP) and rider’s anthropometric and ROM characteristics together. Thus, the present research is the first of its kind study to establish such association (using multiple linear regression) by considering both anthropometric and ROM of the rider in case of motorcycle. Result of the present research also included the intra and inter variable correlations between dimensions of RP and rider’s physical characteristics (anthropometry and ROM) by mentioning the strength and direction of the relationships.
6.5.2 Contribution towards methodological perspective
Methodology adopted in the present research was robust in terms of the selection of appropriate tools and techniques backed by the reliability and validity through statistical analyses.
Developed co-ordinate measurement instrument (laser-based and in-house fabricated) for measuring the dimensions of motorcycles was calibrated, and reliability of the measurements were checked (R2=0.999). For measuring anthropometric dimensions, ROM and CRP (perceived comfort body joint angles), standard methodologies were adopted along with the
assessment of reliability of the measurement process. Image processing technique was utilized for easy capturing of riding postures as well as riding positions. Moreover, principal component analysis was used to identify the key anthropometric dimensions, ROM variables, CRP and RP. The optimal riding position out of the nine test conditions (defined by the positions of the 3 interface points) was estimated using Taguchi Design of Experiments (DOE).
The methodologies adopted for data acquisition, representation, and statistical analysis for interpretation in the context of defining CRP and optimal riding position to ensure ergonomic design of motorcycle would be very useful for the motorcycle designers/ engineers. The present research methodology would act as guide-book to address the postural discomfort due anthropometric and ROM incompatibility of the targeted users with the design of the motorcycles. Indian motorcycle manufacturers should be encouraged to implement the design methodology adopted in this study. It will undoubtedly help in improving the ergonomics design of Indian motorcycle models.
6.5.3 Contribution to the motorcycle design process
Dimensional data of the standard motorcycles generated from the present research would be useful for deciding the dimensions of the standard motorcycle simulator or test-rig for the experimental and training purposes. It is expected that this data would act as a benchmarking dataset for the designers during their design modification or conceptualizing a new design of motorcycle. Developed anthropometric, ROM, and comfort joint angle data-sets would be used in the proactive ergonomic assessment (using DHM software) of the new motorcycle design as described in section 6.4. In addition, an optimum riding position, and thereby CRP could be ensured during the conceptual stage of the motorcycle design process. Findings of the association study of CRP and RP with the physical characteristics (anthropometry and ROM) of the rider can be utilized to decide the dimensions and positions of the handlebar, seat and footrest. Overall, all the findings of the present research have high potentials to support the designers/ engineers in the motorcycle design process.
6.5.4 Contribution to society
Various findings of the present research suggest plausible ways to improve the degree of postural comfort in terms of body joint angles of the riders. Design of a new motorcycle or redesigning of existing one based on the anthropometric and ROM data for defining optimal riding position and thereby CRP would certainly reduce muscular discomfort/ pain of the motorcyclists. Most of these findings are feasible and easy to implement by the designers/
engineers of the motorcycle manufacturing industry. Implementations of these findings would definitely address the identified problems of postural discomfort (body parts discomfort or pain) due to anthropometric and ROM incompatibilities with the dimensions of the motorcycle’s interface points (handlebar, sea and footrest). It is envisaged that improvement in riding posture through ergonomic design of motorcycle would certainly reduce the discomfort of the riders and thereby minimize the possibility of motorcycle accident due to this factor (postural discomfort). Ergonomic design of the motorcycles would ensure the better health of motorcyclists and thus enhanced road safety.