The purpose of this retrospective study was to assess the pain experiences of 17 healthy subjects who trained with isometric exercise, electrical stimulation, and the combination of isometric exercise and electrical stimulation. The McGill Pain Questionnaire was administered during posttest sessions upon termination of 5 weeks of training.

Results indicated that subjects who received the electrical stimulation mode of training experienced similar torque gains but less muscle soreness than those who used conventional isometric exercise. Most subjects of the exercise and electrical stimulation groups experienced pain at the medial aspect of their knee, The pain was predominantly expressed as a sensory rather than an effective or an evaluative quality. Of all the trained subjects, those who received electrical stimulation described the greatest amount of transient discomfort. Electrical stimulation does not appear to increase the risk of discomfort more than volitional resistive exercise for achieving similar force-developing capacity of muscle in healthy subjects.

J Orthop Sports Phys Ther 1984;5(6):318-323.

The purpose of this study was to evaluate the effect of electrode placement in relation to muscle design for producing muscle torque when using neuromuscular electrical stimulation (NMES). Thirty-five healthy subjects (19 men, 16 women) participated in this study on a voluntary basis. All subjects were tested for maximum voluntary isometric contraction (MVC) of their dominant quadriceps femoris muscle while seated on an isokinetic dynamometer. NMES to subject tolerance was used while determining the effect of electrode placement (longitudinal and transverse) on the torque. Findings show that the longitudinal electrode position produces significantly more torque than the transverse position when the knee extensor muscles are electrically stimulated by the same current amplitude. Physical therapists should be aware of this technique when using NMES clinically to produce muscle torque.

J Orthop Sports Phys Ther 1990;11(11):530-534.

J Orthop Sports Phys Ther 1991;13(6):316-321.

The purpose of this study was to determine whether there were differences in the amount of muscle soreness and serum creatine kinase (CK) produced when ratios of electrically induced muscle contraction time to rest time were varied. Fifteen subjects were randomly assigned to one of three groups, each receiving 10, 15-second electrically induced isometric contractions of the quadriceps femoris muscle with rest periods of 10, 30, and 50 seconds between contractions, respectively. The intensity of the contractions were maintained at 30 percent of an individual's maximum voluntary isometric contraction (MVC). Blood samples for serum CK activity, an indicator of muscle damage, and perceived soreness were collected pretreatment, 24, 48, and 72 hours following the single treatment session. Significant increases in the serum CK and perceived soreness ratings were observed in all groups. Postexercise serum CK increases were found to be significantly different between the 10 seconds and the 30-seconds and 50-seconds rest period groups. Clinically, muscle soreness may result from initial trials of neuromuscular electrical stimulation (NMES) with peak amplitudes sufficient to produce contractions equivalent to 30 percent of the MVC. Contraction time to rest ratios of NMES may influence the amount of muscle damage produced.

J Orthop Sports Phys Ther 1991,13(6):310-315.

J Orthop Sports Phys Ther 1993;17(4):177-184.

Key Words: electrical stimulation therapy, magnetics

Understanding the afferent neural system of the knee is considered to be vital to rehabilitation planning. An intricate relationship exists involving the afferent neural receptors in the inert and contractile tissues of the knee. Traditional rehabilitation strategies may not exploit this extensive afferent neural system. Closed kinetic chain functional training (CKCFT) may provide a method for more effectively rehabilitating an injured or reconstructed knee. The rationale for CKCFT has traditionally focused on mechanical aspects. Sensorimotor integration through motor learning is believed to be an important component of CKCFT. The purposes of this review are to discuss: 1) the afferent neural system of the knee with emphasis on the mechanoreceptors, 2) the influence of the afferent neural system of the knee on motor learning, and 3) how CKCFT uses the afferent neural system of the knee and motor learning during knee rehabilitation. This review reinforces the use of CKCFT in knee rehabilitation plans.

J Orthop Sports Phys Ther. 1994;19(1):2-11.

Key Words: articular neurology, motor learning, knee rehabilitation