In our data and media-driven world, the concept of multitasking has regressed from being perceived to be a character trait or capacity of “strength”, to an activity that is now “a sin”. Perhaps, the pendulum has swung too far and has not fully considered that admonishing the practice of multitasking, does not appreciate the inevitable if not obligatory presence of distractions in our world. For the purpose of this blog, we will reduce the scope from multi to dual tasking; and will reduce the overarching themes of labels “good/bad” to focus on the “necessary” in the realms of work and sport.
As a primary musculoskeletal/orthopedic or even sports-based physiotherapist, you are working regularly with patients that need one overarching capability comprised of three closely related but distinct skills, related to dual tasking:
First, the overarching capability that can be expressed to a patient, employee, athlete, coach, or medical reviewer includes the tolerance of dual task environments without loss of motor control.
Second, the three distinct skills needed to accomplish this capability include:
- Automaticity of a set of primary movements that do not require consistent online conscious attention.
- Awareness of environmental variables that command a change in the motor program.
- Ability to recognize and extinguish irrelevant environmental variables, that can be ignored without relevance to the end goal.
A few common examples of when/why dual task practice is essential for your patients might be helpful. One example in sport would include the soccer midfielder that is returning to competition after ACL reconstruction. She does not have the time and cannot afford the attentional resources to consistently monitor her now recovered knee. If she devotes attention to this body part, she is most certainly sacrificing critical resources required to monitor the game dynamics that might and should include where her teammates and opponents are, game context, coach’s feedback, as well as learning opportunities that she could be gathering about opponent tendencies. Our time in rehabilitation with this athlete cannot stop with the physical capabilities and even sport psychology/confidence, but must continue-on such that her movement is automatized. You might correctly refer to this as “second nature” or “motor memory”, but in the world of dual tasking literature, the process is referred to as implicit learning of procedural memories, or retraining automaticity.
Consider that prior to injury, many of the repeated movements that we do in life, sport, and work, require a level of automaticity for the highest-level of function. Movement becomes automatized or procedural in nature not solely because of practice (repetitions), but also because of the regular combination of task with a secondary distractor. We walk, brush teeth, pull on a t-shirt, and get out of bed, largely without thinking… because of the dual tasking expectations that we place on ourselves. Physiologically, dual tasking encourages, compels, and at times all out forces the brain to process motor tasks in one of four procedural memory centers: basal ganglia, cerebellum, supplementary motor area, and the premotor cortex.
Applications of dual task training should always include considerations of task specificity and patient engagement. Consider the sport, work, and life roles and responsibilities of this person in an effort to best engage and most readily transfer learning. While it may be tempting to have a soccer player engage in dual tasking by requesting that they count backwards by 3s while dribbling the ball upfield, it may be better for them to call out the names or uniform numbers of their teammates as a secondary task. Perhaps a more complex, yet relevant task for this same player is to dribble, advance and verbalize their coach’s feedback just shouted from the sidelines. It is additionally worth noting the nearly universally-accepted definition of dual tasking includes the stipulation that both tasks be discrete in measurement and function, meaning that they can be performed separately and that one is not a function of the other. Meaning, carrying a cup of water is a complex single task, not a dual task. Whereas pouring water from a pitcher to a cup while walking is a dual task.
Finally, we must consider dosage. How hard to “load” distraction, and how much error, or degradation of motor control, is appropriate. At this time in the science of dual tasking rehabilitation and in a forum of this length, we can say that dosage is built on patient personality and objective tolerance. We load dual task and both expect and announce an expectation, of error. Patients participating in dual tasking may have more than 40% regression in motor performance (measured by more time to perform a task, slower walking/running speed, or reduced accuracy). Additionally, the frequency of error tolerated for one is not the same for all – as noted due to personality and psychology. It is for this reason, that we must announce the expectation that performance would initially be expected to regress with the introduction of dual tasking.
Dual tasking may be a novel concept, or one that you are ready to both understand and apply at a deeper level. No matter your starting point, one thing that we can all agree-on, is that ignoring the research and practice of dual tasking only harms our patients.
Your takeaway concepts include:
- Dual task rehabilitation is a complimentary and necessary part of comprehensive recovery.
- Patients that have practiced dual task are more likely to be habituated-to and tolerant-of distractions on return to sport or work.
- Dual task interference, when prescribed at the right dosage, can facilitate the procedural memory transfer of patients’ motor learning.
- Dosing dual task should be considerate of patient personalities (success vs error rates), roles, responsibilities, goals, and preferences.