Normative Median and Ulnar Nerve Conduction Values, Mayo Clinic Arizona EMG laboratory.

1<p>Amplitude values for sensory studies are microvolts and motor studies are millivolts.</p>2<p>Note that some normal values for subjects 60 years old and older are gender specific. M = male; F = female.</p

Grip device and experimental variables.

<p>Panel A shows the front view of the grip device used for each grip type condition. All dimensions shown are in cm. Force/torque (F/T) sensors are mounted on both sides of the device to measure forces and moment of forces exerted by each digit involved in a given grip type condition (thumb, index, middle, ring, and little fingers: T, I, M, R, and L, respectively). A mass (<i>“G”</i>; 100 g or 400 g) was inserted in the midpoint at the bottom of the grip device (“Light mass” and “Heavy mass”, respectively). For the 2- and 4-digit grip types, the center of the thumb sensor was collinear with the center of the index or middle finger sensor, respectively. For the 3- and 5-digit grip types, the center of the thumb sensor was collinear with the mid-point between the centers of the index and middle finger or middle and ring finger sensors, respectively. Note that for each grip type, all five sensors were mounted on the grip device to maintain a constant mass for a given mass condition, thus changes in grip types were implemented by changing the relative position of F/T sensors. A magnetic tracker (not shown) was used to track the object position and orientation of the object during the manipulation. ‘O’ denotes the point about which moments were computed (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053751#s2" target="_blank">Methods</a> for more details). Panel B shows, from top to bottom, the time course of the sum of all digit grip forces (F<i>_G</i>), the sum of all digit tangential forces (F<i>_T</i>), and the derivatives of F<i>_G</i> and F<i>_T</i>. Data are aligned with object lift onset (vertical dashed line, a). Note that analysis of digit forces during object hold was performed on data averaged over the last 2 seconds of the hold (horizontal bar, b). Data are from one representative CTS patient (S3) and her matched control (left and right column, respectively) performing the task on the seventh trial for the “light mass” condition and two grip types (two- and five-digit, 2D and 5D, respectively).</p

Grip force at object lift onset and during object hold.

<p>Grip force (F<i>_G</i>) measured at object lift onset and during object hold (top and bottom row, respectively) is shown for each subject group and grip type. Data are mean values averaged across trials 3 through 7 for each subject group and mass condition (left and right column). Vertical bars denote standard errors.</p

Individual Digits’ Normal Force (F<i>n</i>) and Tangential Force (F<i>tan</i>) at Object Lift Onset Averaged across Subjects within Each Group and Grip Type.

<p>Individual Digits’ Normal Force (F<i>n</i>) and Tangential Force (F<i>tan</i>) at Object Lift Onset Averaged across Subjects within Each Group and Grip Type.</p

Subjects’ Basic Information and CTS Patient’s Results of Electrodiagnostic Tests.

1<p>Normative values are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053751#pone-0053751-t002" target="_blank">Table 2</a>. Sensory studies are orthodromic.</p>2<p>Amplitude values for sensory studies are microvolts and motor studies are millivolts.</p>3,4<p>Conduction velocities and F-wave latencies were normal for all nerve studies.</p

Compensatory moment at object lift onset and its components.

<p>The absolute value of the moment exerted on the object (M<i>com</i>) at object lift onset is shown for the light and heavy mass (left and right column, respectively) for each grip type and subject group. Data are mean values averaged across trials 3 through 7 for each subject group. Vertical bars denote standard errors.</p

Time course of grip force as a function of grip type in CTS and controls.

<p>The time course of grip force (F<i>_G</i>) from contact to object release is shown for a representative CTS patient (S3) and her control subject (left and right column, respectively) for the light and heavy mass conditions (top and bottom row, respectively). Data are from the last trial of each block performed with each grip type (two-, three-, four- and five-digit grasps are denoted by 2D, 3D, 4D, and 5D, respectively) and are aligned relative to object lift onset (vertical dashed line).</p

Digit force rates.

<p>Panel A shows the time course of the rate of the sum of digit tangential forces exerted by all digits (F<i>_T)</i> rate from trial 1 through 7 for one CTS patient and her control aligned with respect to peak F<i>tan</i> rate. The vertical line denotes the time of object lift onset averaged across trials. Panel B shows peak rate of F<i>_T</i> and F<i>_G</i> averaged across trials 2 through 7 and subjects for each group and object weight. Vertical error bars denote standard errors.</p

Grip forces during object hold.

<p>Panel A shows the time courses of grip force (sum of all digit normal forces, F<i>_G</i>) from a representative CTS patient (S7) and his matched control (right and left column, respectively) across a block of trials (<i>n</i> = 7) for each weight condition. Data are aligned relative to object lift onset (vertical line). The horizontal arrows denote the mean duration of object hold averaged across trials. Panel B shows F<i>_G</i> during object hold averaged across trials and subjects for the CTS and control group for each weight condition. Vertical error bars denote standard errors. Asterisk indicates statistically significant difference between the two subject groups (<i>P</i><0.05).</p

Experimental setup and variables.

<p>Panel A shows the grip device used for the experiments. Force/torque sensors (F/T) are mounted on both sides of the device to measure forces and moment of forces exerted by each digit (thumb, index, middle, ring, and little fingers: T, I, M, R, and L, respectively). A position/orientation (P/O) sensor was mounted on the top of the device to measure object kinematics. A mass (<i>G</i>: 100 g, 200 g, or 400 g) was inserted at the bottom of the grip device for each experimental condition. Dimensions are in cm. Panel B shows, from top to bottom, the time course of the object vertical position and digit normal and tangential forces (F<i>n</i> and F<i>tan</i>, respectively). Force traces are aligned with object lift onset (vertical line). Forces were analyzed at object lift onset and the last 2 seconds of object hold (striped area) used for analysis of F<i>n</i>. Data are from one representative CTS patient (S3) and her matched control (right and left column, respectively) performing the task on the third trial (445 g condition).</p