Effect of high-voltage pulsed current on recovery after grades I and II lateral ankle sprains.

CONTEXT: High-voltage pulsed current (HVPC), a form of electrical stimulation, is known to curb edema formation in laboratory animals and is commonly applied for ankle sprains, but the clinical effects remain undocumented. OBJECTIVE: To determine whether, as an adjunct to routine acute and subacute care, subsensory HVPC applied nearly continuously for the first 72 h after lateral ankle sprains affected time lost to injury. DESIGN: Multicenter, randomized, double-blind, placebo-controlled trial. SETTING: Data were collected at 9 colleges and universities and 1 professional training site. PARTICIPANTS: 50 intercollegiate and professional athletes. INTERVENTIONS: Near-continuous live or placebo HVPC for 72 h postinjury in addition to routine acute and subacute care. MAIN OUTCOME MEASURE: Time lost to injury measured from time of injury until declared fit to play. RESULTS: Overall, time lost to injury was not different between treated and control groups (P = .55). However, grade of injury was a significant factor. Time lost to injury after grade I lateral ankle sprains was greater for athletes receiving live HVPC than for those receiving placebo HVPC (P = .049), but no differences were found between groups for grade II sprains (P = .079). CONCLUSIONS: Application of subsensory HVPC had no clinically meaningful effect on return to play after lateral ankle sprain.

Effects of Ibuprofen and High-Voltage Electric Stimulation on Acute Edema Formation After Blunt Trauma to Limbs of Rats.

Context: Ibuprofen is widely used to manage pain and inflammation after orthopaedic trauma, but its effect on acute swelling has not been investigated. Cathodal high-voltage pulsed current (CHVPC) at 120 pulses per second and 90% of visible motor threshold is known to curb edema formation after blunt trauma to the hind limbs of rats.Objective: To examine the effects of ibuprofen, continuous CHVPC, and simultaneous ibuprofen and CHVPC on acute edema formation after blunt trauma to the hind limbs of rats.Design: Randomized, parallel-group, repeated-measures design.Setting: Laboratory animal facility.Participants: A total of 21 3-month-old Zucker Lean rats (mass = 288 +/- 55 g) were studied.Intervention(s): We assessed the effects of ibuprofen, continuous CHVPC, and simultaneous ibuprofen and CHVPC on acute edema formation after blunt trauma to the hind limbs of rats.Main Outcome Measure(s): Limb volumes were measured immediately before and after trauma and every 30 minutes over the 4 hours of the experiment.Results: Volumes of treated limbs of all 3 experimental groups were smaller (P < .05) than those of untreated limbs, but no treatment was more effective than another.Conclusions: Ibuprofen, CHVPC, and simultaneous ibuprofen and CHVPC effectively curbed edema after blunt injury by roughly 50% relative to untreated but similarly injured control limbs of rats.

Cool-Water Immersion and High-Voltage Electric Stimulation Curb Edema Formation in Rats.

OBJECTIVE: Although cryotherapy and high-voltage electric stimulation, both alone and in combination, are commonly applied to curb acute edema, little evidence from randomized controlled studies supports these procedures. Our purpose was to examine the effects of cool-water immersion (CWI) at 12.8 degrees C (55 degrees F), cathodal high-voltage pulsed current (CHVPC) at 120 pulses per second and 90% of visible motor threshold, and the combination of CWI and CHVPC (CWI + CHVPC) on edema formation after impact injury to the hind limbs of rats. DESIGN AND SETTING: Both feet of 34 rats were traumatized after hind-limb volumes were determined. Animals were randomly assigned to 1 of 3 groups: CWI (n = 10), CHVPC (n = 10), or CWI + CHVPC (n = 14). One randomly selected hind limb of each rat was exposed to four 30-minute treatments, interspersed with four 30-minute rest periods beginning immediately after posttraumatic limb volumes were determined. Contralateral limbs served as controls. Limbs remained dependent during all treatments, rest periods, and volumetric measurements. SUBJECTS: We used 34 anesthetized Zucker Lean rats in this study. MEASUREMENTS: We measured limb volumes immediately before and after trauma and after each of 4 treatment and rest periods. RESULTS: Volumes of treated limbs of all 3 experimental groups were smaller (P <.05) than those of untreated limbs. No treatment was more effective than another. CONCLUSIONS: Cool-water immersion, cathodal high-voltage electric stimulation, and simultaneous application of these treatments were effective in curbing edema after blunt injury. Combining CWI and CHVPC was not more effective than either CWI or CHVPC alone.

Effects of Cool-Water Immersion and High-Voltage Electric Stimulation for 3 Continuous Hours on Acute Edema in Rats.

OBJECTIVE: Cool-water immersion (CWI) at 12.8 degrees C (55 degrees F), cathodal high-voltage pulsed current (CHVPC) at 120 pulses per second and 90% of visible motor threshold, or the combination of CWI and CHVPC, applied 30 minutes on, 30 minutes off for 4 hours, are known to curb edema formation after blunt trauma to the hind limbs of rats. Our purpose was to examine the effects of extending treatment times to 3 continuous hours after blunt trauma to the hind limbs of rats. DESIGN AND SETTING: A randomized, parallel-groups design of 22 subjects was used. Volumes of traumatized limbs, randomly assigned to CWI (n = 7), CHVPC (n = 8), or CWI followed by CHVPC (n = 7) were compared with those of injured but untreated limbs with analysis of variance. SUBJECTS: Twenty-two anesthetized Zucker lean rats (mass = 293 +/- 27 g). MEASUREMENTS: We measured limb volumes immediately before and after trauma and every 30 minutes over the 4-hour experiment. RESULTS: Volumes of treated limbs of all 3 experimental groups were smaller than those of untreated limbs (P <.05). No treatment was more effective than another. CONCLUSIONS: Exposure to either 3 hours of CWI or CHVPC or to 1 hour of CWI followed by 2 hours of CHVPC effectively curbed edema after blunt injury. These results suggest that these common treatments are effective only during application and hint that application should be maintained throughout the period during which edema is forming.

Foot of two-toed sloths: Its anatomy and potential uses relative to size of support.

Feet of two-toed sloths (Choloepus) are long, narrow, hook-like appendages with only three functional digits, numbers II, III, and IV; Rays I and V are represented by metatarsals. Proximal phalanges of complete digits are little more than proximal and distal articulating surfaces. All interphalangeal joints are restricted, by interlocking surfaces, to flexion and extension. Ankle and transverse tarsal joints, however, allow extreme flexion and inversion of foot. Powerful digital flexion is augmented by several muscles from extensor compartment of leg. Intrinsic foot musculature is reduced to flexors and extensors but these, with the exception of lumbricals, are large and well developed. Choloepus uses its feet much like hooks with distal phalanges and covering claws forming the "hook" element. These hook-like appendages are seemingly best suited for supports less than 50 mm in diameter suggesting that two-toed sloths may prefer supports of this size in their natural habitat.

The hand of two -toed sloths (Choloepus): Its anatomy and potential uses relative to size of support.

Hands of two-toed sloths (Choloepus) are long, narrow, hook-like apparatuses with only two functional digits (II and III); rays I and IV are represented only by metacarpals. The proximal phalanges of digits II and III are shortened to essentially proximal and distal articulating surfaces, and all but distal interphalangeal joints of these digits are restricted by interlocking surfaces to minimal ranges of flexion and extension. Several intercarpal joints and the wrist joint, however, allow wide ranges of movement in several axes. Wide excursion at the wrist is permitted by an extremely lax joint capsule, the manner of insertion of several prime movers of the carpus, and the reduced participation of the ulna in the wrist joint. Several extrinsic digital muscles, particularly extensors, are absent and others have unusual actions. Intrinsic musculature consists primarily of mm. interossei and m. extensor digitorum brevis, although other, inconstant muscles do occur. Hands of Choloepus are used as flexible hooks on supports less than 52 mm in diameter and as fixed grapnels on larger supports. In both cases, distal phalanges (and covering claws) form the "hook" element. Whereas bare volar pads seem to be adjunctive on supports smaller than 52 mm in diameter, they are essential on those larger than 65 mm. Two-toed sloths may prefer supports 50 mm in diameter or smaller. The potential importance of vines as supports is discussed.

The wrist joint of two-toed sloths and its relevance to brachiating adaptations in the hominoidea.

Two-toed sloths have evolved a wrist complex that includes the following traits: (1) diminution and distal migration of the pisiform, with a loss of contact with the ulna; (2) reduction of the distal end of the ulna to a styloid process; and (3) extremely reduced contact between the ulna and triquetrum. These traits were proposed by Lewis ('65, '74) to be indicative of brachiating habits and to be a unique adaptation of the Hominoidea. Cartmill and Milton ('77) recently found a similar complex in the wrists of the lorisines. Very similar adaptations of the wrist among the Hominoidea, lorisines, and two-toed sloths clearly refute contentions of Lewis and strengthen the hypothesis of Cartmill and Milton that the traits common to those animals are due to similar slow, cautious, but acrobatic locomotion.