The main finding of this study was that the Finnish version of RM4-FM provides valid and reliable scores in physical activity motivation assessment. Nevertheless, our findings showed limitations regarding the targeting of the dimension scores and a need for consideration of factor structure of RM4-FM (Table 4).
Table 4
Predefined hypotheses and conclusions for validation of the RM4-FM.
Feature | Hypothesis | Conclusion |
---|
Coverage and targeting | | |
Floor and ceiling effect | No floor effect (min score ≤ 15%) | |
| Intrinsic motivation | Confirmed |
| Identified regulation | Confirmed |
| Introjected regulation | Confirmed |
| External regulation | Rejected |
| No ceiling effect (max score ≤ 15%) | |
| Intrinsic motivation | Confirmed |
| Identified regulation | Rejected |
| Introjected regulation | Confirmed |
| External regulation | Confirmed |
Validity | | |
Cross-cultural validity | Non-significant associations between the RM4-FM score and sociodemographic characteristics | Confirmed /Rejected |
Convergence with the PAAQ | Significant and at least low correlation between the PAAQ and the RM4-FM scores | Confirmed /Rejected |
Structural validity | | |
CFA | Chi-square test non-significant | Rejected |
| RMSEA < 0.05 | Rejected |
| CFI > 0.95 | Rejected |
| SRMR < 0.80 | Rejected |
EFA | Unidimensional structure of dimensions | |
| Intrinsic motivation | Confirmed |
| Identified regulation | Confirmed |
| Introjected regulation | Confirmed |
| External regulation | Confirmed |
| | |
Internal consistency | Cronbach’s alpha is ≥ 0.7 | |
| Intrinsic motivation | Confirmed |
| Identified regulation | Confirmed |
| Introjected regulation | Confirmed |
| External regulation | Confirmed |
Reliability | | |
Test-retest reliability | ICC ≥ 0.7 | |
| Intrinsic motivation | Confirmed |
| Identified regulation | Confirmed |
| Introjected regulation | Confirmed |
| External regulation | Confirmed |
CFA = Confirmatory Factor Analysis |
EFA = Exploratory Factor Analysis |
RMSEA = Root Mean Square Error of Approximation |
CFI = Comparative Fit Index |
SRMR = Standardized Root Mean Square Residual |
ICC = Intraclass Correlation Coefficient |
There is a lack of validated instruments concerned with motivation of physical activity for the Finnish population. In this study, the translation and cross-cultural validation of the RM4-FM was performed according to internationally submitted guidelines 37. There were only minor discrepancies between two forward translated versions, as well as between the original and backward translated versions, and these discrepancies did not affect the content of the instrument. Furthermore, the examination of the association of sociodemographic factors and RM4-FM scores indicated good cross-cultural validity of RM4-FM.
The scale targeting of RM4-FM dimensions was not optimal on the basis of the distributions and coverage of each dimension scores. The scores of the dimensions associated to internal motivation (Intrinsic motivation and Identified regulation) were skewed towards high scores and a ceiling effect was confirmed in Identified regulation dimension, whereas External regulation score was skewed towards low scores and was confirmed with a floor effect. The result suggests that applicability of RM4-FM is limited in a sample of highly internally motivated people. A study by Nurmi et al (2005) 24 investigated the mediator effect of self-regulation in the association between intrinsic motivation and participation in physical activity in adolescents using a broadly similar questionnaire with minor differences (SRQ-E). The scores of Intrinsic motivation and Identified regulation dimensions in that study were focused around high scores with mean scores 3.84 (SD 0.97) and 3.85 (SD 0.96), respectively. On the other hand, the mean scores of External regulation and Introjected regulation were 1.78 (SD 0.85) and 2.78 (SD 1.09). The distributions of the scores in the study by Nurmi et al. 24 and in the present study were very similar supporting the suggestion that scale targeting and ceiling effects might be a problem independent of age group.
The confirmatory factor analysis (CFA) showed that RM4-FM did not obey the presumed four-dimension structure. The results of CFA on the four-dimensional model indicated weak structural validity of RM4-FM. In addition, despite the sufficiency of Cronbach alphas of the RM4-FM and its dimensions, the values were relatively low, especially within the individual dimensions. Low Cronbach alphas of the dimensions may be due to a low number (4) of items in each dimension, but, on the other hand, it may reflect that items within the dimensions do not measure the same construct. The exploratory factor analysis (EFA) produced a best-fit model of three factors: influence of other people, intention of well-being and emotions of physical activity. The three-factor model showed at least comparable, if not better, performance in psychometric properties compared to the original model. However, despite the strengths of the three-factor model, it is limited due to losing the basis and division in motivation dimensions based on the Self-determination theory 8. The three-factor model would provide specific information on motivation from a different perspective than the original model. Nevertheless, the EFA of single RM4-FM dimensions showed unidimensionality of each dimension, which in turn support the sufficiency of structural validity and applicability of the four-dimensional model of RM4-FM.
High ICC values indicated high test-retest reliability with one-month re-completion interval. Motivation for physical activity is a dynamic phenomenon that may vary depending on changing situations and mood of one’s life. High ICC suggests that RM4-FM is not strongly affected by these varying circumstances, but it rather reflects more permanent aspects of motivation.
There were some limitations in the present study. Firstly, criterion validity of RM4-FM was not measured, as there was not a sufficient instrument to compare the results. Secondly, the study sample was limited to older individuals (i.e. 65–75 years of age), which, in addition, may be influenced by a high rate of chronic diseases and medication use in the sample. The age and health status of the participants may have also affected habits and attitudes, as well as motivation for physical activity, particularly since the present sample were highly functionable for their age despite the fact that they were not physically activity. The advantages of this study were a large randomly selected sample from the Population Register, which represents well the average population as the regularly physically active individuals were excluded, as well as comprehensive translation and statistical methods, which adhere to the international guidelines on questionnaire validation studies. In addition, the questionnaires were completed electronically, and the questionnaire program required the participant to complete all the items, thus, preventing missing data.
In conclusion, the Finnish version of RM4-FM instrument provides valid and reliable scores in assessing motivation for physical activity in a sample of healthy, older Finnish adults. However, regarding the floor and ceiling effects of the dimensions, the scale seemed to be improperly targeted suggesting shortages in the scale when evaluating internally motivated subjects. A three-factor model of the RM4-FM provided more favorable psychometric properties than the original version though it loses the basis of Self-Determination Theory. The three-factor model is a noteworthy alternative when assessing motivation for physical activity using the RM4-FM. This work may aid in future translations into other languages and uses of the questionnaire.