Abstract
Objectives
Theories from the cognitive psychology literature, such as those of dual-task interference, provide an important insight into some of the information-processing demands that are inherent in the performance of physical activities of daily living. This study aimed to quantify dual-task decrement when performing a physical task with a concurrent memory task, in order to examine the implications of dual-task performance for physiotherapy practice.
Design
A quasi-experimental design was chosen consisting of three trials. Each participant completed one set of three trials. The trials consisted of one single-task physical test, one single-task memory test and the dual-task condition.
Participants
The sample consisted of twenty-five female participants, aged 20–37 years (mean age 25.0
±3.9 years), who were recruited incidentally. Inclusion criteria included self-declared right-handedness with no recent upper limb neuromusculoskeletal injury or disease.
Interventions
Force data were collected for the right elbow flexors during a sustained isometric maximal voluntary contraction.
Main outcome measures
Force, recorded as Newtons using a strain gauge, and the results of a memory test.
Results
Under dual-task conditions both force production and memory recall were significantly impaired (P<0.01). The mean force in the dual task was 91.3N (95% confidence interval 81.1 to 101.5N). The mean number of words recalled in the group who learnt the words in the dual task was 7.3 (95% confidence interval 6.1 to 8.4) and the mean number of words in the group who recalled the words in the dual task was 9.6 (95% confidence interval 8.1 to 11.1). The average decrement in force and number of words recalled was similar for both (∼16%). This may be a result of sharing of a limited attention capacity between the two tasks.
Conclusions
Results may have important implications for physiotherapy practice in suggesting that patients should not be subjected to an overload of cognitive information whilst trying to achieve maximal strength gains during a rehabilitation programme.
Citation
Measurement of force production during concurrent performance of a memory task
Victoria Salmon, Di Thomson
Physiotherapy - December 2007 (Vol. 93, Issue 4, Pages 283-290, DOI: 10.1016/j.physio.2007.02.006)