Extensor Tendon Injury
An Occupational Therapy Perspective
Prehension
Grasp taxonomy
Click on button to view the GRASP taxonomy and the various types of grips to consider
With regards to Felix, he will be using a relative motion splint. Although he will still be able to stay relatively functional, there will be a few restrictions on the types of grips. Firstly, the power grip category requires a firm grip between the hands and the object with most of the movement of the object completed by the arm. With the splint, Felix should still be able to perform the power grips, but with less strength due to a certain finger being placed in greater extension. He should still be able to engage in cylindrical power grip, but greater difficulty with smaller diameter as the splint limits the amount of flexion in the metacarpal-phalangeal joint. Again, he may be able to complete grasping spherical objects or using scissors, but he will not be able to exert the same amount of force relative to when he was able to use all his fingers at once. The second category is precision, which describes a grip that occurs all within the hand and does not require movement of the arm to move the object. Depending on the finger that will be in greater extension, Felix may have difficulty with some of the precision grips. This may include pinching with more than the thumb and one other finger or holding a writing utensil. The extension of the wrist may also make it more difficult to complete tasks. With regards to Felix’s work demands, he should still be able to type on a keyboard with moderate ease. He will just need to practice and familiarize himself to restricted movement and may need to reduce the speed of his typing.
Article discussing the distribution of force of the hands while engaging in different grips for activities of daily living
Our hands are our essential tools for everyday tasks and independent living. In order to understand how an extensor tendon rupture affects Felix’s occupational performance, the types of grip he can and cannot perform must be identified. Broadly, grasp is any static hand position in which an object is held in the hand (Feix, Pawlik, Schmiedmayer, Romero, and Kragic, 2008). The first classification system which attempted to organize human grasping was developed by Schlesinger in 1919. This system included 6 types of grasps which are, cylindrical, tip, hook, palmar, spherical and lateral. There is little consensus about the classification of human grasp types. However more recent works by Feix, Romero, Schmiedmayer, Dollar and Kragic (2015) reviewed literature and developed the GRASP taxonomy. This taxonomy classifies grasp in categories of power, precision and intermediate types with subcategories in relation to thumb position and finger/palm contact type. The authors included 33 grasp types that were valid in relation to the definition of grip. Also they indicate that the taxonomy not only looks at hand pose but also the contact between the hand and what is being held.
Click on this image of the GRASP Taxonomy to view the study that discusses the classification system
It is important to note how frequent a certain type of grip is required by Felix when he engaged in his occupations. Frequencies of the different types of grip vary greatly according to the setting the individual occupies. Complying to what Felix needs, the OT can prioritize which grasp types to work on and make sure that he can sufficiently perform them during and after the use of a splint. Modifications may also be required if the splint limits the type of grip that is required to engage in the specific task.
The video below demonstrates and instructs how to measure grip and pinch stength in a clincal setting
The study by Pylatiuk, Kargov, Schulz and Döderlein (2006) aims to measure required force generated by the hand to perform some functional activities of daily living (ADL). Force sensors were placed on the palmar surface of the hand to measure force contribution of every finger and parts of the palm. The data generated from this study will be able to provide information regarding the amount of force and which fingers are needed to complete functional tasks that Felix may require. Having some normative data to compare with, we can assess grip and pinch strength of the client. Understanding Felix’s ability to generate a certain amount of force will indicate if he will be able to complete certain tasks and what interventions are needed to improve his strength. This study does provide proof of a clinical concept because the data generated aims to contribute to the knowledge of grip force required to complete ADLs.
WEBSITE
References:
Dollar, A. (2014). Classifying Human Hand Use and the Activities of Daily Living. Springer Tracts In
Advanced Robotics, 201-216. http://dx.doi.org/10.1007/978-3-319-03017-3_10
Feix, T., Romero, J., Schmiedmayer, H., Dollar, A., & Kragic, D. (2016). The GRASP Taxonomy of
Human Grasp Types. IEEE Transactions On Human-Machine Systems, 46(1), 66-77.
http://dx.doi.org/10.1109/thms.2015.2470657.
Pylatiuk, C., Kargov, A., Schulz, S., and Doderlein, L. (2006). Distribution of grip
forced in three different functional prehension patterns. Journal of Medical Engineering,
30(3), 176-182. DOI: 10.1080/03091900600565217.