Determining Sincerity of Effort Based on Grip Strength Test in Three Wrist Positions

BACKGROUND: Several grip strength tests are commonly used for detecting sincerity of effort. However, there is still no widely accepted standardized sincerity of effort test. Therefore, this study aimed to examine whether grip strength test in three wrist positions could distinguish between maximal and submaximal efforts. METHODS: Twenty healthy individuals (10 men and 10 women) with a mean age of 26.7 ± 3.92 years participated in this study. All participants completed two test conditions (maximal and submaximal efforts) in three wrist positions (neutral, flexion, and extension) using both hands. Each participant exerted 100% effort in the maximal effort condition and 50% effort in the submaximal effort condition. The participants performed three repetitions of the grip strength test for each session. RESULTS: The results showed that there is a significant main effect of the type of effort (p < 0.001), wrist position (p < 0.001), and hand (p = 0.028). There were also significant types of effort and wrist position interactions (p < 0.001) and effort and hand interactions (p < 0.028). The results also showed that grip strength was highest at the wrist in neutral position in both the maximal and the submaximal effort condition. Grip strength values of the three wrist positions in the maximal effort condition were noticeably greater than those in the submaximal effort condition. CONCLUSION: The findings of this study suggest that grip strength test in three wrist positions can differentiate a maximal effort from a submaximal effort. Thus, this test could potentially be used to detect sincerity of effort in clinical setting.

Position Change of the Neurovascular Structures around the Carpal Tunnel with Dynamic Wrist Motion

OBJECTIVE: The purpose of this study was to determine the anatomic relationships between neurovascular structures and the transverse carpal ligament so as to avoid complications during endoscopic carpal tunnel surgery. METHODS: Twenty-eight patients (age range, 35-69 years) with carpal tunnel syndrome were entered into the study. We examined through wrist magnetic resonance imaging in three different positions (neutral, radial flexion, and ulnar flexion) and determined several anatomic landmark (distance from the hamate hook to the median nerve, ulnar nerve, and ulnar vessel) based on the lateral margin of the hook of the hamate. The median nerve and ulnar neurovascular structure were studied with the wrist in the neutral, ulnar, and radial flexion positions. RESULTS: The ulnar neurovascular structures usually passed just over or ulnar to the hook of the hamate. However, in 12 hands, a looped ulnar artery coursed 0.6-3.3 mm radial to the hook of the hamate and continued to the superficial palmar arch. The looped ulnar artery migrates on the ulnar side of Guyon's canal (-5.2-1.8 mm radial to the hook of the hamate) with the wrist in radial flexion. During ulnar flexion of the wrist, the ulnar artery shifts more radially beyond the hook of the hamate (-2.5-5.7 mm). CONCLUSION: It is appropriate to transect the ligament greater than 4 mm apart from the lateral margin of the hook of the hamate without placing the edge of the scalpel toward the ulnar side. We would also recommend not transecting the transverse carpal ligament in the ulnar flexed wrist position to protect the ulnar neurovascular structure.

Cases Report of Carpal Tunnel Syndrome in Two Patients with Dyskinetic Cerebral Palsy: Two cases report

Carpal tunnel syndrome (CTS) is the most frequent entrapment mono-neuropathy, a pressure-induced neuropathy of the median nerve at the wrist. Two patients with dyskinetic cerebral palsy presented tingling sense of bilateral hands and marked flattening of both thenar eminences. In two patients, the involuntary dystonic muscle contractions kept the wrist position in hyperextension or more frequently, in hyperflexion with ulnar deviation and finger in flexion strongly. We performed careful history taking and physical examination, and then diagnosed bilateral carpal tunnel syndrome in two patients through medical workup including electromyography and ultrasonography. In this report, we present these cases and discuss their physiopathology.

The Effect of Wrist Position on the Conduction Velocity of the Ulnar Nerve

OBJECTIVE: The purpose of this study was to investigate the effect of wrist position on the ulnar nerve conduction velocity. METHOD: Ulnar motor nerve conduction studies were performed bilaterally in twenty healthy adult volunteers. For each limb, nerve conduction study was carried out in two different positions. In the first position, shoulder were abducted, elbow and wrist flexed to 90o. For the second position, all joints were kept constant except for the wrist where it was extended. Routine conduction study was performed in both wrist positions. All data were statistically analyzed. RESULTS: The average conduction velocities in the wrist flexed position were 61.6 m/sec for the forearm segment and 62.3 m/sec across elbow. With the wrist extended, the average was 62.6 m/sec and 64.1 m/sec, respectively. The differences in conduction velocities between two different wrist positions were statistically significant (p<0.05). In the wrist flexed position, the average measured latencies were 2.3 msec with wrist, 5.4 msec below elbow, and 7.4 msec above elbow stimulation, compared to wrist extended which showed 2.4, 5.4 and 7.2 msec, respectively. The difference of latencies at wrist between the two wrist positions was statistically significant (p<0.05). CONCLUSION: The authors conclude that wrist position affect ulnar nerve conduction velocity.