Determining Validity of Measures of Pain and Perceived Effort of Women With Hand Osteoarthritis During a Jar Opening Task.

Purpose: Joint protection strategies are often recommended for individuals with hand arthritis. However, there is little research regarding their effectiveness or on the use of self-report measures in evaluating the effects of joint protection strategies. The purpose of this study was to examine the relationship between the self-report measures of pain and perceived exertion and actual hand forces used during the everyday task of opening a sealed jar in order to validate their use in measuring the effectiveness of joint protection strategies such as using a counterforce such as a table or opposing extremity and using a nonskid material. A secondary purpose was to evaluate the effects of the type of grasp, the hand grasping the lid, and the use of non-skid material on the hand forces acting upon ajar lid when breaking a jar's seal. Methods: A novel jar device created by McGee, Nuckley, and Mathiowetz1 was used to gather measurements of grip force, compressive force down through the lid's axis of rotation (Fz), shear force tangential to the lid (Fy), and compressive force perpendicular to the side of the lid (Fx) (Figure 1a) when attempting to open a 'sealed jar'. The jar lid's torque requirement was set to 4.24 Nm, a torque commonly imposed by the manufacturer when creating a seal on larger diameter jars. Thirty-one women with hand osteo-arthritis were asked to complete 16 jar opening simulations by alternating three different factors: hand turning the jar lid, position (supinated/vertical and power/diagonal), and use of a non-skid material (Figure 1b). After each jar turning simulation, participants were asked to report their perceived level of pain and exertion using the 0 to 10 scales of the NRS and Borg CRIO, respectively. Results: The impact of arthritis on our sample's function was modest (AIMS2-SF2 Total Health Score x = 10.62) and the distribution of arthritis between hands was not dissimilar (Table 1). Descriptive data is presented in Figures 1c and id. A significant, Distribution of hand arthritis Joint Distribution Avg # digits involved Right 2.09, Left 2.03 1st CMC (90%) Bilateral 23/31 (74%) Unilateral 5/31 (16%) (4R, 1L) Wrist level (TriScaph) (16%) Bilateral 2/31 (6.5%) Unilateral 3/31(9.5%) (2R, 1L) Other Digits RIF (39%), RLF (35%), LIF (39%), LLF (33%) positive relationship was found between pain, as measured by the NRS, and the actual hand forces utilized while opening a sealed jar (2.2>(3 >18.8, p > .03). A more significant and positive relationship was found between perceived effort and hand force/time (1.4>p >59.0, p>.001). Use of the supinated grasp required less force/time in Fx [F(1,419) = 30.5, p <.0001 ], Fy [F(1,419) = 34.5, p