Knee Rehabilitation Following Surgical Procedures
Excessive external rotation and abduction of the tibia while the knee is in a partially flexed, weightbearing position may produce injuries resulting in both medial and rotatory instability of the knee. Medial instability is defined as abnormal outward rotatory displacement of the tibia with respect to the femur. 1 On examination, damage may be found in the posteromedial compartment of the knee and may involve the medial capsular ligament with or without accompanying involvement of the tibial and remaining portions of the medial collateral liga ments. 2 In the presence of simple instability of the knee (instability in only one plane), conservative treat ment is often elected, including immobilization in a long leg cast for protection of the injured tissue. In the presence of complex instability (instability in two or more planes of movement), surgical correc tion, however, such as the Slocum-Larson proce dure or pes anserinus transfer is required. 4 Pes anserinus is the name given to the common fascia of the insertion of the semitendinosis, gracilis, and sartorius muscles. This common fascia is located in the distal posteromedial aspect of the knee. In the transfer procedure, the more posterior aspect of this fascia is released, flapped up and over on itself and then reattached in a more anteromedial position. This new alignment offers support of the damaged medial collateral ligaments and, more importantly, provides an active stability in its new major role as an internal rotator of the tibia. 4 In both conservative and surgical approaches to the treatment of this problem, the knee is usually immobilized in a position of approximately 25 to 30 degrees of knee flexion with the tibia internally rotated in order to relieve any unnecessary stresses on the damaged tissue. The following program is presented for use as a guideline for rehabilitation in conjunction with both treatment regimens.
PHASE I: RANGE OF MOTION The rehabilitation program stresses exercises which may be adapted to a home program and Mr. Ostrom is Director of Physical Therapy, Day Kimball Hospital, 320 Pomfret St, Putnam, CT 06260.
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RUSSELL C. OSTROM, MS
require as little equipment as possible. Early reha bilitation following a period of immobilization stresses 1) range of motion in order to prevent further adaptive shortening of the muscle and artic ular changes within the joint, and 2) strengthening of the quadriceps muscle for knee stability. Active range-of-motion exercises emphasize the regaining of knee extension as this is usually the most difficult task for the patient. The program consists of quadriceps muscle setting with simulta neous ankle dorsiflexion. This pattern of motion not only facilitates quadriceps muscle strengthening, but also provides an active stretch of the triceps surae muscle which often has developed a contrac ture from having been immobilized in the cast. Slight elevation of the lower leg with firm support under the ankle further aids knee extension while performing this pattern of motion. Another exercise which is effective in aiding knee extension can be performed by the patient while he is sitting in a chair. Sitting on the edge of the chair, the patient extends his lower leg as far forward as possible; the heel maintains contact with the floor. Using his hands, the patient then applies a force into extension directly to the knee. This exercise is also useful for stretching hamstring muscles. Knee flexion can usually be obtained gradually but steadily through active and gentle active assis tive motions into flexion. If common exercise tech niques are employed to attain this motion, however, we have found that discomfort in the knee, and not muscle shortening or articular changes, is usually the limiting factor in the performance of range-ofmotion exercises, especially flexion exercises, fol lowing knee surgery. This discomfort is greatly diminished if active assistive exercises accompanied by gentle oscillating motions, ie rhythmical jiggling, are substituted for passive stretch. A maintained passive stretch, even if gently ap plied, results in a crescendo effect on pain levels. With increasing discomfort there is more guarding by the patient, whether it be voluntary or involun tary. The discomfort not only prevents increasing motion, but also in itself seems to increase the level of discomfort. The overall effect is a pain-guardingpain cycle. This crescendo effect can be prevented
PHYSICAL THERAPY
PHASE II: STRENGTH-ENDURANCE
Fig.l. Assisted knee flexion.
When the patient is able to attain full active extension and is free of any discomfort during active tibial rotation, resistive exercises are initiated for the quadriceps, pes anserinus, and hamstring mus cles. The emphasis of the exercise program is differ ent for each of these muscles.
by substituting the assistive motion using minimal gentle oscillations during stretching. The use of a towel as an assistive device usually enables the patient to assist himself in performing flexion exer cises with little difficulty (Fig. 1). With a reduction of pain, the patient is usually more cooperative and performs better on a home exercise program.
Muscle fibers have been divided into two major types: fast-twitch fibers and slow-twitch fibers. 7 Fast-twitch fibers are used in work of short duration and high intensity and can be referred to as the fibers for "strength." Slow-twitch fibers are more suited for work of longer duration but of lower intensity and can be considered "endurance" fibers.
An important motion of the knee which I have found to be overlooked in many knee rehabilitation programs is that of tibial rotation. Abduction and external rotation of the tibia is mechanically neces sary during full knee extension. Conversely, adduc tion and internal rotation of the tibia accompanies knee flexion. The amount of rotation varies greatly with individuals as well as with the position of the knee joint. The amount of rotation is usually great est at 90 degrees of flexion and decreases as the knee moves into extension. This is due to both the increasing tautness of the ligamentous structures and the cupping action of the femoral condyles with the articulating surfaces of the tibia. 6
Human muscle is composed of a mixture of these fibers. The relative proportion of fiber types is dependent upon the functional role of the muscle. Flexors or phasic muscles, such as the biceps brachialis, are considered to have a greater proportion of fast twitch fibers. Postural muscles, such as the quadriceps, will have a greater proportion of slowtwitch fibers. 7
A reduction also occurs in the mechanical advan tages of the pes anserinus muscle group (which is greatest at 90 degrees of flexion) during knee exten sion because of its decreasing angle of insertion (Fig. 2). The reduction in mechanical advantage results in a corresponding decrease in the flexion and internal rotational force of this muscle group. 1 For this reason, active tibial rotation exercises into internal rotation are not initiated until the patient has achieved approximately 75 to 80 degrees of flexion. Reeducation of the pes anserinus group is easier for the patient with the added mechanical advantage of the knee flexed position. We have also found that regaining active tibial external rota tion facilitates knee extension. Volume 57 / Number 12, December 1977
The specificity of the muscle's function, and con sequently its relative proportion of fiber types,
Fig. 2. Reduction in mechanical advantage of the pes anserinus as the knee is moved into extension. 1
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Downloaded from https://academic.oup.com/ptj/article-abstract/57/12/1376/4558749 by Washington University in St. Louis user on 13 February 2019
Of special consideration in postoperative joint rehabilitation is the avoidance of unnecessary joint irritation, especially in the presence of any persist ent joint edema. Unnecessary irritation may in crease the chance of developing chronic synovitis and may result in additional damage of internal structures in a joint already under pressure from increased fluid.
should direct the emphasis of a retraining program toward either strength or endurance exercises. For the quadriceps muscle, endurance training would be emphasized, and, for the hamstring muscles, strength training would be stressed. Initially all resistive exercises to the quadriceps muscle are performed with the knee fully extended during straight leg raising. A typical program would have the patient starting with a 1-pound ankle cuff used for resistance. His goal would be 30 repetitions at this weight. The procedure here is important. While semireclining with the opposite knee bent, the patient locks his knee into extension. He then lifts his leg, holds for a count of three, and then lowers his leg, completely relaxing the quadriceps muscle for at least a 1-count. This relaxation is vital in order to allow circulation to be restored through the muscle and prevent fatigue due solely to circu latory occlusion. The patient would then remove the 1-pound ankle cuff and repeat the exercise with a new goal of 50 repetitions for endurance training. This routine would be progressed using 1-pound increments. The long-range goal for termination of the exercise would be dependent upon the individ ual's functional and occupational requirements.
ADDITIONAL CONSIDERATIONS In knee rehabilitation, we should actually be concerned with total lower extremity rehabilitation. Muscles of the hip and leg should be evaluated for changes in strength and endurance and proper func tional rehabilitation exercises initiated for any dec rements found.
Resistive knee-flexion exercises for hamstring strengthening are initiated only when the patient is able to attain full active flexion without discomfort. Rubber tubing can be used to provide resistance for this muscle group (Fig. 3). The degree of resistance can be increased by adjusting the length of the tubing. If the pes anserinus transfer is analyzed with respect to its protective function, that is, the provi sion of both medial and rotatory support to the knee during stance, it becomes obvious that any force into valgus affects the medial aspect of the
1378
Fig. 4. Positioning of the lower leg into internal rotation in preparation for eccentric training of the pes anserinus group.
PHYSICAL THERAPY
Downloaded from https://academic.oup.com/ptj/article-abstract/57/12/1376/4558749 by Washington University in St. Louis user on 13 February 2019
Fig. 3. Resistive knee flexion exercises using rubber tubing.
knee and would be opposed by the eccentric or lengthening contraction of this muscle group. This is an important consideration in terms of the speci ficity of exercise. The force that a muscle can produce during a state of controlled lengthening, that is eccentric force, is greater than the force that it can produce during shortening or its concentric force. 8 Concentric training has not been proven to be as effective as eccentric training in increasing maximal eccentric force. 9 Consequently, if the de sired function of any muscle group is eccentric in nature, eccentric exercises must be used in order to obtain the desired training effect. Eccentric training can be carried out in this rehabilitation program by again using rubber tubing as a resistive device (Fig. 4). The tibia is passively placed in internal rotation and is then actively controlled by the patient as the tubing pulls the tibia back into external rotation. Resistive exercises should be temporarily discon tinued if the following clinical signs occur: increased joint edema, discomfort, or prolonged warmth over the joint after the cessation of the exercise.
prescribed exercise program. Increasing the pa tient's awareness usually results in increasing his motivation. The patient is then given a written basic exercise prescription at the time of discharge. The chances that he will adhere to the program are greatly improved because the patient has been com pletely involved in his rehabilitation program. Leav ing the formal surroundings of the clinic does not, and should not, mean the termination of treatment.
REFERENCES
1. Noyes FR, Sonstegard DA: Biomechanical function of the pes anserinus at the knee and the effect of its transplantation. J Bone Joint Surg [Am] 55:1225-1241, 1973 (Illustration reprinted with permission) 2. Kennedy JC, Fowler PJ: Medial and anterior instability of the knee. J Bone Joint Surg [Am] 53:1257-1270, 1971 3. Nicholas JA: The five-one reconstruction for anteromedial instability of the knee: Indications, technique and the results in fifty-two patients. J Bone Joint Surg [Am] 55:899-922, 1973 4. Slocum DB, Larson RL: Pes anserinus transplantation. J Bone Joint Surg [Am] 50:226-242, 1968
5. Kettelkamp DB: Clinical implications of knee biomechanics. Arch Surg 107:406-410, 1973 6. Slocum DB, Larson RL: Rotatory instability of the knee. J Bone Joint Surg [Am] 50:211-225, 1968 7. Gollnick PD, Hermansen L: Biochemical adaptations to exer cise. In Wilmore J (ed): Anaerobic Metabolism from Exercise and Sport Sciences Review. New York, Academic Press, Inc, 1973 8. Asmussen E: Positive and negative muscular work. Acta Physiol Scand 28:364-382, 1953 9. Komi PV, Buskirk ER: Effect of eccentric and concentric muscle conditioning on tension and electrical activity of human muscle. Ergonomics (London) 15:417-434, 1972
Now... A New File Binder for PHYSICAL THERAPY A new model tough construction binder of reinforced fiberboard may be ordered featuring PHYSICAL THERAPY embossed in gold. Strong metal wires hold 12 issues to make a single-volume set. The older model maroon leatherette file box is still available for storing issues with the issue numbers clearly visible. Both designs keep the Journal orderly, readily acces sible for reference and guard against soiling, tearing, or misplacement of copies. A slip of gold transfer foil for indexing volume and year accompanies (free) every file. Order directly from the manufacturer. Boxes are $4.95 each; 3 for $14.00; and 6 for $24.00. Binders are $6.50 each; 3 for $18.75; 6 for $36.00, post paid.
JESSE JONES BOX CORPORATION POST OFFICE BOX 5120
Volume 57 / Number 12, December 1977
PHILADELPHIA, PA 19141
1379
Downloaded from https://academic.oup.com/ptj/article-abstract/57/12/1376/4558749 by Washington University in St. Louis user on 13 February 2019
Patients are often discharged from outpatient clinics before full functional rehabilitation can be completed. This may be due to a variety of reasons but is most often the result of financial circum stances. The problem produced by early discharge can usually be remedied by completely involving the patient in his rehabilitation program through discussion of the initial injury, surgical corrections, muscle functions, and the reasoning behind the
Excessive external rotation and abduction of the tibia while the knee is in a partially flexed, weightbearing position may produce injuries resulting in both medial and rotatory instability of the knee. Medial instability is defined as abnormal outward rotatory displacement of the tibia with respect to the femur. 1 On examination, damage may be found in the posteromedial compartment of the knee and may involve the medial capsular ligament with or without accompanying involvement of the tibial and remaining portions of the medial collateral liga ments. 2 In the presence of simple instability of the knee (instability in only one plane), conservative treat ment is often elected, including immobilization in a long leg cast for protection of the injured tissue. In the presence of complex instability (instability in two or more planes of movement), surgical correc tion, however, such as the Slocum-Larson proce dure or pes anserinus transfer is required. 4 Pes anserinus is the name given to the common fascia of the insertion of the semitendinosis, gracilis, and sartorius muscles. This common fascia is located in the distal posteromedial aspect of the knee. In the transfer procedure, the more posterior aspect of this fascia is released, flapped up and over on itself and then reattached in a more anteromedial position. This new alignment offers support of the damaged medial collateral ligaments and, more importantly, provides an active stability in its new major role as an internal rotator of the tibia. 4 In both conservative and surgical approaches to the treatment of this problem, the knee is usually immobilized in a position of approximately 25 to 30 degrees of knee flexion with the tibia internally rotated in order to relieve any unnecessary stresses on the damaged tissue. The following program is presented for use as a guideline for rehabilitation in conjunction with both treatment regimens.
PHASE I: RANGE OF MOTION The rehabilitation program stresses exercises which may be adapted to a home program and Mr. Ostrom is Director of Physical Therapy, Day Kimball Hospital, 320 Pomfret St, Putnam, CT 06260.
1376
Downloaded from https://academic.oup.com/ptj/article-abstract/57/12/1376/4558749 by Washington University in St. Louis user on 13 February 2019
RUSSELL C. OSTROM, MS
require as little equipment as possible. Early reha bilitation following a period of immobilization stresses 1) range of motion in order to prevent further adaptive shortening of the muscle and artic ular changes within the joint, and 2) strengthening of the quadriceps muscle for knee stability. Active range-of-motion exercises emphasize the regaining of knee extension as this is usually the most difficult task for the patient. The program consists of quadriceps muscle setting with simulta neous ankle dorsiflexion. This pattern of motion not only facilitates quadriceps muscle strengthening, but also provides an active stretch of the triceps surae muscle which often has developed a contrac ture from having been immobilized in the cast. Slight elevation of the lower leg with firm support under the ankle further aids knee extension while performing this pattern of motion. Another exercise which is effective in aiding knee extension can be performed by the patient while he is sitting in a chair. Sitting on the edge of the chair, the patient extends his lower leg as far forward as possible; the heel maintains contact with the floor. Using his hands, the patient then applies a force into extension directly to the knee. This exercise is also useful for stretching hamstring muscles. Knee flexion can usually be obtained gradually but steadily through active and gentle active assis tive motions into flexion. If common exercise tech niques are employed to attain this motion, however, we have found that discomfort in the knee, and not muscle shortening or articular changes, is usually the limiting factor in the performance of range-ofmotion exercises, especially flexion exercises, fol lowing knee surgery. This discomfort is greatly diminished if active assistive exercises accompanied by gentle oscillating motions, ie rhythmical jiggling, are substituted for passive stretch. A maintained passive stretch, even if gently ap plied, results in a crescendo effect on pain levels. With increasing discomfort there is more guarding by the patient, whether it be voluntary or involun tary. The discomfort not only prevents increasing motion, but also in itself seems to increase the level of discomfort. The overall effect is a pain-guardingpain cycle. This crescendo effect can be prevented
PHYSICAL THERAPY
PHASE II: STRENGTH-ENDURANCE
Fig.l. Assisted knee flexion.
When the patient is able to attain full active extension and is free of any discomfort during active tibial rotation, resistive exercises are initiated for the quadriceps, pes anserinus, and hamstring mus cles. The emphasis of the exercise program is differ ent for each of these muscles.
by substituting the assistive motion using minimal gentle oscillations during stretching. The use of a towel as an assistive device usually enables the patient to assist himself in performing flexion exer cises with little difficulty (Fig. 1). With a reduction of pain, the patient is usually more cooperative and performs better on a home exercise program.
Muscle fibers have been divided into two major types: fast-twitch fibers and slow-twitch fibers. 7 Fast-twitch fibers are used in work of short duration and high intensity and can be referred to as the fibers for "strength." Slow-twitch fibers are more suited for work of longer duration but of lower intensity and can be considered "endurance" fibers.
An important motion of the knee which I have found to be overlooked in many knee rehabilitation programs is that of tibial rotation. Abduction and external rotation of the tibia is mechanically neces sary during full knee extension. Conversely, adduc tion and internal rotation of the tibia accompanies knee flexion. The amount of rotation varies greatly with individuals as well as with the position of the knee joint. The amount of rotation is usually great est at 90 degrees of flexion and decreases as the knee moves into extension. This is due to both the increasing tautness of the ligamentous structures and the cupping action of the femoral condyles with the articulating surfaces of the tibia. 6
Human muscle is composed of a mixture of these fibers. The relative proportion of fiber types is dependent upon the functional role of the muscle. Flexors or phasic muscles, such as the biceps brachialis, are considered to have a greater proportion of fast twitch fibers. Postural muscles, such as the quadriceps, will have a greater proportion of slowtwitch fibers. 7
A reduction also occurs in the mechanical advan tages of the pes anserinus muscle group (which is greatest at 90 degrees of flexion) during knee exten sion because of its decreasing angle of insertion (Fig. 2). The reduction in mechanical advantage results in a corresponding decrease in the flexion and internal rotational force of this muscle group. 1 For this reason, active tibial rotation exercises into internal rotation are not initiated until the patient has achieved approximately 75 to 80 degrees of flexion. Reeducation of the pes anserinus group is easier for the patient with the added mechanical advantage of the knee flexed position. We have also found that regaining active tibial external rota tion facilitates knee extension. Volume 57 / Number 12, December 1977
The specificity of the muscle's function, and con sequently its relative proportion of fiber types,
Fig. 2. Reduction in mechanical advantage of the pes anserinus as the knee is moved into extension. 1
1377
Downloaded from https://academic.oup.com/ptj/article-abstract/57/12/1376/4558749 by Washington University in St. Louis user on 13 February 2019
Of special consideration in postoperative joint rehabilitation is the avoidance of unnecessary joint irritation, especially in the presence of any persist ent joint edema. Unnecessary irritation may in crease the chance of developing chronic synovitis and may result in additional damage of internal structures in a joint already under pressure from increased fluid.
should direct the emphasis of a retraining program toward either strength or endurance exercises. For the quadriceps muscle, endurance training would be emphasized, and, for the hamstring muscles, strength training would be stressed. Initially all resistive exercises to the quadriceps muscle are performed with the knee fully extended during straight leg raising. A typical program would have the patient starting with a 1-pound ankle cuff used for resistance. His goal would be 30 repetitions at this weight. The procedure here is important. While semireclining with the opposite knee bent, the patient locks his knee into extension. He then lifts his leg, holds for a count of three, and then lowers his leg, completely relaxing the quadriceps muscle for at least a 1-count. This relaxation is vital in order to allow circulation to be restored through the muscle and prevent fatigue due solely to circu latory occlusion. The patient would then remove the 1-pound ankle cuff and repeat the exercise with a new goal of 50 repetitions for endurance training. This routine would be progressed using 1-pound increments. The long-range goal for termination of the exercise would be dependent upon the individ ual's functional and occupational requirements.
ADDITIONAL CONSIDERATIONS In knee rehabilitation, we should actually be concerned with total lower extremity rehabilitation. Muscles of the hip and leg should be evaluated for changes in strength and endurance and proper func tional rehabilitation exercises initiated for any dec rements found.
Resistive knee-flexion exercises for hamstring strengthening are initiated only when the patient is able to attain full active flexion without discomfort. Rubber tubing can be used to provide resistance for this muscle group (Fig. 3). The degree of resistance can be increased by adjusting the length of the tubing. If the pes anserinus transfer is analyzed with respect to its protective function, that is, the provi sion of both medial and rotatory support to the knee during stance, it becomes obvious that any force into valgus affects the medial aspect of the
1378
Fig. 4. Positioning of the lower leg into internal rotation in preparation for eccentric training of the pes anserinus group.
PHYSICAL THERAPY
Downloaded from https://academic.oup.com/ptj/article-abstract/57/12/1376/4558749 by Washington University in St. Louis user on 13 February 2019
Fig. 3. Resistive knee flexion exercises using rubber tubing.
knee and would be opposed by the eccentric or lengthening contraction of this muscle group. This is an important consideration in terms of the speci ficity of exercise. The force that a muscle can produce during a state of controlled lengthening, that is eccentric force, is greater than the force that it can produce during shortening or its concentric force. 8 Concentric training has not been proven to be as effective as eccentric training in increasing maximal eccentric force. 9 Consequently, if the de sired function of any muscle group is eccentric in nature, eccentric exercises must be used in order to obtain the desired training effect. Eccentric training can be carried out in this rehabilitation program by again using rubber tubing as a resistive device (Fig. 4). The tibia is passively placed in internal rotation and is then actively controlled by the patient as the tubing pulls the tibia back into external rotation. Resistive exercises should be temporarily discon tinued if the following clinical signs occur: increased joint edema, discomfort, or prolonged warmth over the joint after the cessation of the exercise.
prescribed exercise program. Increasing the pa tient's awareness usually results in increasing his motivation. The patient is then given a written basic exercise prescription at the time of discharge. The chances that he will adhere to the program are greatly improved because the patient has been com pletely involved in his rehabilitation program. Leav ing the formal surroundings of the clinic does not, and should not, mean the termination of treatment.
REFERENCES
1. Noyes FR, Sonstegard DA: Biomechanical function of the pes anserinus at the knee and the effect of its transplantation. J Bone Joint Surg [Am] 55:1225-1241, 1973 (Illustration reprinted with permission) 2. Kennedy JC, Fowler PJ: Medial and anterior instability of the knee. J Bone Joint Surg [Am] 53:1257-1270, 1971 3. Nicholas JA: The five-one reconstruction for anteromedial instability of the knee: Indications, technique and the results in fifty-two patients. J Bone Joint Surg [Am] 55:899-922, 1973 4. Slocum DB, Larson RL: Pes anserinus transplantation. J Bone Joint Surg [Am] 50:226-242, 1968
5. Kettelkamp DB: Clinical implications of knee biomechanics. Arch Surg 107:406-410, 1973 6. Slocum DB, Larson RL: Rotatory instability of the knee. J Bone Joint Surg [Am] 50:211-225, 1968 7. Gollnick PD, Hermansen L: Biochemical adaptations to exer cise. In Wilmore J (ed): Anaerobic Metabolism from Exercise and Sport Sciences Review. New York, Academic Press, Inc, 1973 8. Asmussen E: Positive and negative muscular work. Acta Physiol Scand 28:364-382, 1953 9. Komi PV, Buskirk ER: Effect of eccentric and concentric muscle conditioning on tension and electrical activity of human muscle. Ergonomics (London) 15:417-434, 1972
Now... A New File Binder for PHYSICAL THERAPY A new model tough construction binder of reinforced fiberboard may be ordered featuring PHYSICAL THERAPY embossed in gold. Strong metal wires hold 12 issues to make a single-volume set. The older model maroon leatherette file box is still available for storing issues with the issue numbers clearly visible. Both designs keep the Journal orderly, readily acces sible for reference and guard against soiling, tearing, or misplacement of copies. A slip of gold transfer foil for indexing volume and year accompanies (free) every file. Order directly from the manufacturer. Boxes are $4.95 each; 3 for $14.00; and 6 for $24.00. Binders are $6.50 each; 3 for $18.75; 6 for $36.00, post paid.
JESSE JONES BOX CORPORATION POST OFFICE BOX 5120
Volume 57 / Number 12, December 1977
PHILADELPHIA, PA 19141
1379
Downloaded from https://academic.oup.com/ptj/article-abstract/57/12/1376/4558749 by Washington University in St. Louis user on 13 February 2019
Patients are often discharged from outpatient clinics before full functional rehabilitation can be completed. This may be due to a variety of reasons but is most often the result of financial circum stances. The problem produced by early discharge can usually be remedied by completely involving the patient in his rehabilitation program through discussion of the initial injury, surgical corrections, muscle functions, and the reasoning behind the
