Effects of Joint Mobilization on Joint Stiffness and Active Motion of the Metacarpal- Phalangeal Joint

Transcription

1 Effects of Joint Mobilization on Joint Stiffness and Active Motion of the Metacarpal- Phalangeal Joint Terry Randall, MS, PT, OCS, ATC' Leslie Portney, MS, PT2 Bette Ann Harris, MS, PT3 J oint mobili~ation has been a popular treatment for the restoration of joint motion for many years. Hippocrates first described the use of gentle passive motion to loosen a stiffjoint. The interest in nianual therapy has waxed and waned with prevailing medical practice. In recent years, several prominent physicians and therapists have described specific techniques of joint riiobili7ation and have developed specific guidelines for their use in examination and treatment (5, 10, 13, 15). These clinicians and others have helped to popularize the use of riianual therapy. Unfortunately, the effects of joint mobili7ation have not been examined sufficiently by controlled studies. Support for its use is based primarily on anatomic and biomechanical studies, as well as anecdotal evidence (14). Even the most basic questions of efficacy have not been answered, most likely because variables related to the application of joint mobilization, such as force and direction, are difficult to quantify (17). Consequently, little research has been done to substantiate the use of joint mobili7ation for increasing joint range of motion. In a beginning effort to study the effects of joint mobilization, this study focuses on the problems of loint mobilization is a common technique used to restore joint motion; however, documentation of its effectiveness is lacking. The purpose of this study was to determine if joint mobilization is effective in counteracting joint stiffness and decreased active range of motion of the metacarpalphalangeal joint. It was hypothesized that there would be a significant increase in range of motion in those patients who received joint mobilization. Eighteen subjects who had been immobilized for the treatment of metacarpal fractures were randomly assigned to a treatment group that received joint mobilization or a control group that received no treatment. Measurements of active range of motion and torque range of motion prior to and after treatmentlrest sessions were obtained for three sessions over a I week period. Analyses of variance were performed on the mean changes in excursion between groups and across sessions. The joint mobilization resulted in a significantly greater increase in excursion for subjects in the treatment group over subjects in the control group (p < 0.05). loint mobilization does appear to be able to counteract the ehects of immobilization and alter joint mechanics. Key Words: joint mobilization, joint stiffness, metacarpal-phalangeal ' Assistant chief ofphysical therapy, Reynolds Army Hospital, Ft. Sill, OK. CPJ Randall was a student at the Massachusetts General Hospital Institute of Health Professions, Graduate Program in Physical Therapy, Boston, MA, when this study was completed. Assistant professor, MGH Institute of Health Professions, Graduate Program in Physical Therapy, Boston, MA 'Assistant professor and clinical research associate, Department of Physical Therapy, Massachusetts General Hospital, Boston, MA joint stiffness and decreased active range of motion (AROM) that accompany immobilization of the hand following fracture. Metacarpal fractures, treated with immobili7ation incorporating the metacarpal-phalangeal (MCP) joint, are a common injury for which measurable changes in ROM can be documented and joint mobili7ation can be performed. The effects of immobilization on joint mobility are well documented, especially in terms of tissue responses (6). Salter's classic works describing the benefits of motion during the healing phase of articular cartilage stem from earlier efforts describing the deleterious effects of immobilization and compression on joints (1 8). A significant loss of water and a decrease in the ground substance called glycoaminoglycans (GAG) can lead to a decrease in the distance between connective tissue fibers, which promotes cross-linking (1). Cross-links between fibers inhibit their normal gliding and, thereby, restrict motion and contribute to joint stiffness (6). Volume 16 Number I July 1992 JOSPT

2 The stiffness of a material is its resistance to deformation. In the case of immobilized joints, stiffness is the resistance to motion. Various components of joint stiffness, including elastic, viscous, inertial, frictional, and plastic stiffness, have been studied (23). Elastic tissue deforms relative to the amount of force applied. The deformation that occurs is related to the intensity of the force only. Plastic stiffness describes a property where tissue initially elongates similar to elastic tissue, but at a certain point, elongation will continue when the force is held constant. This stretch under constant force is called creep. The deformation that occurs with plasticity is dependent on both the intensity and duration of force applied. When the force is removed, the tissue will not return to the original length. In normal joints, the force required to overcome the elastic and plastic components of stiffness is much larger than for the other components (22). Treatment ofjoint stiffness can take many forms. One treatment is passive motion, which is a broad term describing various techniques used to produce motion via external means. Mechanical effects that are attributed to passive motion include prevention and breaking of adhesions, influencing the cellular processes of healing, improving lubrication, and restoring normal joint mechanics (9). Joint mobili7ation is but one method of applying passive motion to a joint. Joint mobilization allows for selective stretching of abnormal tissues and can be expected to change both the elastic and plastic components of stiffness. In order to document these changes, one must be able to accurately quantify the extent of joint stiffness. Traditionally, active and passive range of motion measurements have been used to assess the function of the digits. The basic technique outlined by Moore contin- ues to be utilized (1 6). Hamilton and Lachenbruch (I I) confirmed that intrarater reliability is greater than interrater reliability for hand measurement. The type of goniometer used was not found to have any effect on the reliability of the measurements. While the measurement of motion in this manner is valuable, it does not provide adequate information concerning the mechanics of the joint. Recently, more specific measures of joint stiffness have been proposed. Various components of joint stiffness, including elastic, viscous, inertial, fricfional, and plastic stiffness, have been studied. Brand (3) has described a method of measurement called torque range of motion (TROM), which he states is the only noninvasive method of quantifying the mechanical qualities of the tissues that resist movement. Torque range of motion refers to a method of measuring a joint with standard goniometric methods while a known force is used to position the joint. By using a known force, more objective measurements can be obtained because the patient's or therapist's expectations cannot influence the movement of the joint. This type of measurement has been shown to be a reliable and effective method of analyzing joint stiffness (23). Breger- Lee (4) has tested the reliability of TROM using a goniometer combined with a tensiometer and found the intrarater reliability to be excellent. Protocols for the clinical application of TROM have been described by Bell-Krotoski et al (2). The purpose of this study was to determine if joint mobilization is effective for increasing active motion and decreasing joint stiffness following immobili7ation of the MCP joint. The primary research question focused on the difference between pretest and posttest measurements and a comparison between treatment and control groups. It was hypothesized that subjects who received joint mobilization would demonstrate an increased amount of AROM and less joint stiffness, as measured by TROM, than those who did not receive joint mobili~ation. In addition, the study looked at differences between AROM and TROM measurements, with the expectation that TROM would produce greater excursion in the involved joint. It was also hypothesized that patients who presented with greater initial limitations would demonstrate smaller increases within a treatment session than those who were less limited initially. METHODS Subjects Eighteen subjects between 19 and 46 years old (mean age = 28.7 years) were recruited from the hand clinic at Massachusetts General Hospital (MGH). The subjects were healthy, adult volunteers who had been followed for treatment of a metacarpal fracture and whose hand had been immobilized for least 2 weeks. Subjects were randomly assigned to either a treatment or control group (N = 9 per group). Descriptive data for both groups revealed similar distribution with respect to age, sex, fracture site, and length of immobili7ations (Table 1). All subjects were treated at the same clinic and had similar management of their fractures, including methods of closed reduction, application of the cast, and position of immobili~ation, which was between 70 and 90" IOSPT Volume 16 Number I July 1992

3 Age Mean Range SD Sex Male Female Fracture location Neck Shaft Base Days of immobilization Mean Range SD Control Treatment N=9 N=9 TABLE 1: Descriptive data showing comparability of the two study groups. of metacarpal-phalangeal (MCP) flexion. Subjects were excluded from the study if they had an intra-articular fracture of the MCP joint, open reduction with internal fixation (ORIF), non-union/delayed union, or collagen/rheumatic disease. All subjects signed an informed consent form. This study was approved by the MGH Subcommittee on Human Subjects. Procedure Each subject was scheduled for three appointments on alternate days over a I-week period. The initial session was scheduled within 48 hours after removal of the cast. The treatment group received joint mobilization at each session while the control group rested for a comparable time. Both groups carried out similar home exercise programs between treatment sessions, and no restrictions were placed on their rehabilitation due to the study. Prior to any treatment or measurement a briefing was given to each subject. This served to familiarize the subject with the procedures and ensure that each subject understood the protocol. If pain prevented completion of either the measurement or the treatment during a session, as occurred in one subject, the session was rescheduled for the next day. At each session, subjects were measured for AROM and TROM before and after treatment, or before and after the rest period for the control group. Test-retest trials were taken for all measurements to assess reliability of recording procedures. The sequence of recording was randomized for both AROMITROM and flexion/extension. For all measurements, the subjects were seated with their elbows on the table in front of them, forearms vertical, and their wrists in a neutral position. To assess AROM of the involved MCP, the subject was asked to flex and ex- Traction and palmarl dorsal glide techniques were used to perform the joint mobilization treatment, tend the MCP joint as far as possible. Measurements were taken with a goniometer placed on the dorsal surface of the metacarpal and the proximal phalanx. TROM was assessed using a Haldex tensiometer (Fred Sammons Inc., Box 32, Brookville, IL 60513), which is a hand-held instrument with a short lever connected to a dial marked in grams. The free end of the lever was used to apply a 400-gm force to the digit. The direction of the force followed the normal arc of motion of the proximal phalanx and was perpendicular to the shaft of the proximal phalanx. T o obtain TROM for flexion, force was applied to the distal aspect of the proximal phalanx (Figure 1). For extension, a loop of nylon line was placed around the proximal interphalangeal (PIP) joint in the flexion crease, and force was used pulling perpendicular to the proximal phalanx shaft (Figure 2). The application of the force was done in a smooth manner and completed in 3-5 seconds. The goniometer was read within 3 seconds after reaching the desired position. The author performed all of the treatments and another therapist, who was blinded to the subject's group assignment, performed all measurements. Treatment Intervention Traction and palmar/dorsal glide techniques were used to perform the joint mobilization treatment. Traction was administered by stabilizing the metacarpal bone and distracting the proximal phalanx along its longitudinal axis perpendic- FORCE FIGURE 1. Procedure for measuring flexion torque range of motion. FIGURE 2. Procedure for measuring extension torque range of motion. Volume 16 Number I July 1992 JOSPT

4 ular to the joint surface. Glides were performed by stabilizing the metacarpal bone and applying force to the proximal phalanx very close to the MCP joint, so that the resultant movement was parallel to the joint surface. Two sets of 20 oscillations of each technique were given at a rate of 1 oscillation/sec with a 30- second rest between each set. Fifteen seconds were allowed between each technique. Within each set, the distraction technique was given first, followed by dorsal and palmar glides. The mobilization force was of sufficient magnitude to take up all of the slack in the joint and apply a stretch to the periarticular structures. Between the pretest and posttest measurements, the subjects in the control group rested their hand, in a neutral position with no active or passive motion allowed. The rest period was the same duration as the treatment session. Both groups were given an a p propriate home exercise program to afford them a normal recovery course. Six active exercises, which included both isolated and combined joint movements in all planes, were to be performed 6-8 times/day. No restrictions were placed on the subjects' activities during the study. If their ROM improved sufficiently to allow them to make a closed fist before the third treatment, they were not seen for a third session. After the three sessions were completed, they continued on an appropriate rehabilitation program, supervised as necessary. Data Analysis The test-retest reliability of both AROM and TROM measurements was assessed using ICC (2, 1) to analyze a random sample of four paired measurements from each subject, two AROM and two TROM (1 9). Several analyses were performed to assess differences across treatment sessions. Due to the high number of missing values for the third session, only the first two sessions were used for these analyses. A two-way analysis of variance (ANOVA) with one repeated factor was used to compare the change in ROM achieved by the two groups across sessions. Active range of motion and TROM were analyzed separately. The differences between the pretreatment and posttreatment measurements across treatment sessions were evaluated for each group separately using a two-way ANOVA with two repeated It appears that the initial stiffness is a poor predicfor of frea tmen f response. measures. A similar analysis was used to compare AROM and TROM across sessions for each group separately. The difference in excursion, or total degrees of motion, produced by AROM and TROM within a single test was compared using a one tailed paired t-test. This comparison was based on both pretest and posttest values. The excursion present at the first session pretest, representing the initial amount ofjoint stiffness, was correlated with subsequent ROM changes using the Pearson product moment correlation coefficient. All the analyses were performed at a.05 level of significance. RESULTS Reliability analyses, shown in Table 2, demonstrated that both AROM and TROM measurements were very consistent (ICC =.98). Based on these results, the means of two trials for each measurement were used in all further analyses. The mean change in excursion within each session is shown in Figures 3 and 4 for the treatment and control groups. The changes in excursion is the difference between the pretreatment and posttreatment measures. The change in AROM and TROM were significantly greater in the treatment group than in the control group. The mean excursion for pre and post measurements for AROM and TROM within each session is shown in Figure 5 for the control group and Figure 6 for the treatment group. The difference between the pretest and posttest following joint mobilization was significant for both AROM and TROM for both sessions. The control group showed no significant changes between pre and post measurements for AROM, but did demonstrate a significant difference for TROM. The mean difference between the pre and posttest measurements was only 2". To compare the changes that occurred between sessions, the mean excursion for each measurement in session one was paired with the cor- Mean Difference Range SD ICC AROM TROM TABLE 2: Difference between test-retest trials for evaluating reliability of AROM and TROM. FIGURE 3. Mean changes in excursion produced with AROM comparing groups across sessions. JOSPT Volume 16 Number 1 July 1992

5 Group AROM TROM Min Mean Max Min Mean Max Control Treatment TABLE 3: Degrees of excursion present on the initial visit. FIGURE 8. Mean changes in excursion lor AROM and TROIU between sessions in the treatment group. FIGURE 4. Mean changes in excursion produced with TROM comparing groups across sessions. FIGURE 5. Mean changes in pre to podtest measurements within sessions for the control group. FIGURE 6. Mean changes in pre to posttest measurements within sessions for the treatment group. FIGURE 7. Mean changes in excursion lor AROM and TROM between sessions in the control group. responding measurement in session two (Figures 7 and 8). Both groups showed a significant change between sessions for both AROM and TROM. There was no significant relationship between the amount of stiff- ness present initially and the amount of excursion pined through treatment based on AROM or TROM (r =.07 to.49, P > 0.05). The range of stiffness of the subjects in this study is presented in Table 3. The amount of excursion measured prior to treatment was used as an indication of stiffness. The mean excursions produced with AROM and TROM are shown in Figures 9 and 10. The 400-gm force used to produce the TROM produced significantly greater excursion than AROM (t = 6.77, df = 16, p < 0.01) in both the control and treatment groups. DISCUSSION Although no other studies have specifically tested the effects of joint mobilization in the hand, the finding that it produces significant changes in the treatment group supports current theories concerning the effectiveness of this treatment approach (9, 1 5, 18). The development of these theories did not come from the observation of tissue response to treatment, but, rather, from biomechanical models, and, therefore, they have always been ambiguous. Specific structures which have been altered by the joint mobilization can not be identified from this study. Previous studies have implicated the joint capsules, tendons, and muscles as the tissues restricting the extremes of normal joint motion (1 2). Because the extensor and flexor muscle groups are some distance from the MCP joint, injury to FIGURE 9. Mean excursion produced with AROM and TROM for the control group in pre and posttest trials for sessions 1 and 2 across sessions. FIGURE 10. Mean excursion produced with AROM and TROM for the treatment group in pre and posttest trials for sessions 1 and 2 across sessions. the metacarpal would not affect the muscle or connective tissue sheath. Adhesions and collagen cross-links in the ligament and joint capsule may be the primary extra-articular elements restricting motion in both flexion and extension after fracture of the metacarpal and subsequent immobilization. Joint mobilization could increase excursion by breaking these collagen cross-links, which form as a result of the decrease in GAG. In the traumatized joint, the proliferation of intra-articular fibrofatty deposits will also restrict motion (7). Because the MCP joint was immobilized in a flexed position, the greatest restrictions were lack of extension. Joint mobilization could certainly affect both the joint capsule and the synovial fluid. Additional structures that limit motion at the MCP joint include the volar plate, Volume 16 Number 1 July 1992 JOSPT

6 RESEARCH STUDY - - lumbrical and interosseous muscles, and the skin. Another mechanism by which joint rnobili7ation may aid in restoring motion is by decreasing edema. The intermittent compression and distraction of the joint will redistribute fluid into the soft tissue and allow for easier movement. Joint mobililation may not be responsible for actual lengthening of collagen fibers. Research has shown that the application of low amounts of force over prolonged periods is most effective in obtaining permanent elongation (20, 21). It is not known what values for intensity and duration would be most effective in stretching various types of human tissue. The presence of the inflammatory process plays an important part in the recovery of joint motion. When normal joints are immobilized, the amount of stiffness that develops is minimal. When Flowers and Pheasant (8) immobilized normal PIP joints for up to 6 weeks, full motion was recovered with gentle stress applied in a single 20-minute treatment session. When studies investigating the effects of immobilization are conducted on animal models, the immobilization is usually accomplished via the use of internal fixation. This understandably would trigger the inflammatory process. The singular contributions of trauma and immobilization to the development of joint stiffness are not yet fully understood. Further research may reveal methods of controlling certain aspects of the inflammatory process or altering the type of immobilization to minimize the development of joint stiffness. Both groups had a significant change in AROM and TROM between sessions, that is, there was a noticeable difference from the pretest at session 1 to the pretest at session 2. This is an expected finding considering the natural course of this injury. Improvements in movement during the first 2 weeks follow- ing the removal of the cast would be expected. This natural trend towards improvement is illustrated by the fact that four subjects in the treatment group and one in the control group were not scheduled for their third session due to the early restoration of normal ROM. This is why only two appointment sessions were used in the data analysis. While it appears that the initial stiffness is a poor predictor of treatment response, additional study with a much larger sample size, which represents the full spectrum ofjoint stiffness, may reveal tendencies not uncovered in this study. A wide range of stiffness is represented here but more of the subjects were at the lower end of this range. A sample that is small in number may not provide the correlation expected. Clinical experience suggests that those patients with marked loss of motion following immobilization may require a longer rehabilitation period to regain adequate motion. This study must be considered a preliminary investigation into the effects of joint mobiliration. To establish the effectiveness and proper use of joint mobilization much more work is needed. Further work to define the mechanism of action, reliability and validation of various techniques, and applicability in different situations lies ahead. Similar studies using stiffer joints, such as the PIP joint, and multiple force levels may provide stronger evidence for the effects of joint mobihation. Using the concept of controlled force to position the joint for measurement allows for the investigation of various aspects of joint stiffness such as creep. By applying and maintaining a force over time, the amount of creep can be documented. This refers to the elastic qualities of tissues and how they respond to prolonged stretch. With prolonged stretch, tissues slowly adapt by altering their structure. Scar tissue at different stages of maturity may have vastly different responses to maintained force. CONCLUSION This study investigated the use of joint mobili7ation on stiff MCP joints that had been immobilized following metacarpal fracture. The joint mobilization treatment given to the subjects in this study resulted in a significant gain in AROM and decrease in joint stiffness within a treatment session when compared to the control group. This provides evidence that joint mobilization does alter the mechanics of the joint and increase excursion when measured both actively and with controlled force. JOSPT ACKNOWLEDGMENTS I would like to thank my thesis readers, Leslie Portney, MS. PT, and Bette Ann Harris, MS. PT, for their guidance, patience, and willingness to share their wealth of knowledge with me. They are a credit to the Institute of Health Professions and the profession of physical therapy. I have developed a great deal of respect for the therapists in the hand clinic at Massachusetts General Hospital and appreciate their support and friendship. Special thanks go to Lisa Smiglin for being the "other therapist" whose outstanding clinical expertise and careful measurements made this study worthwhile. Lastly, I would like to acknowledge my family for their encouragement, not only with this thesis but throughout my graduate education. REFERENCES I. Akeson WH, Amiel D, LaViolette D: The connective tissue response to immobility: A study of the chondroitin 4- and 6-sulfate and dermatan sulfate changes in periarticular connective tissue of control and immobilized knees of dogs. Clin Orthop 51: , 1967 JOSPT Volume 16 Number 1 July 1992

7 2. Bell-Krotoski I, Breger D, Beach R: Application of biomechanics for evaluation of the hand. In: Hunter I, Schneider L, Mackin E, Callahan A (eds), Rehabilitation of the Hand (3rd Ed), pp 139. St. Louis: C. V. Mosby Company, Brand P: Clinical Mechanics of the Hand, pp St. Louis: C. V. Mosby Company, Breger-Lee D, Bell-Krotoski I, Brandsma 1: Torque range of motion in the hand clinic. Hand Ther 3:7-13, Cyriax I: Textbook of Orthopedic Medicine-Treatment by Manipulation, Massage and Injection, Vol 2, pp Baltimore: Williams & Wilkins, Donatelli R, Owens-Burkhart H: Effects of immobilization on the extensibility of periarticular connective tissue. I Orthop Sports Phys Ther 3:67-72, Evans EB, Eggers CW, ButlerlK, Blumel I: Experimental immobilization and remobilization of rat knee joints. I Bone loint Surg 42A:737, Flowers K, Pheasant S: The use of torque angle curves in the assessment of digital joint stiffness. I Hand Ther 1 :69-74, Frank C, Akeson W, Woo S, Amiel D, Coutts R: Physiology and therapeutic value of passive joint motion. Clin Or- Chop 185: , Crimsby 0: Fundamentals of Manual Therapy: A Course Workbook. Vagsbydgd, Norway: Sorlandets Fysikalske Institute, Hamilton C, Lachenbruch P: Reliability of goniometers in assessing finger joint angle. Phys Ther 49:465469, johns R, Wright V: Relative importance of various tissues in joint stiffness. j Appl Physiol 17:824, Kaltenborn F: Manual Mobilization of the Extremity joints (4th Ed), Oslo, Norway: Olaf Norlis Bokhandel, MacConaill MA, Basmagian, IF: Muscles and Movements, Huntington, NY: Krieger, Maitland GD: Peripheral Manipulation, Boston: Butterworth & Co, Ltd, Moore M: The Measurement of joint Motion: Part 11. Phys Ther Rev 29: , Nicholson C: The effects of passive joint mobilization on pain and hypomobility associated with adhesive capsulitis of the shoulder. I Orthop Sports Phys Ther 6: , Salter RB, Field P: The effects of continuous compression on living articular cartilage. I Bone loint Surg 42A:3 1, Shrout PE, Fleiss ll: lntraclass correlations: Uses in assessing rater reliability. Psycho1 Bull 86:420428, Warren CC, Lehmann IF, KoblanskilN: Elongation of rat tail tendon: Effect of load and temperature. Arch Phys Med Rehabil52:465474, Warren CG, Lehmann IF, Koblanski IN: Heat and stretch procedures-an evaluation using rat tail tendon. Arch Phys Med Rehabil57: , Wright V, Dowson D, Longfield M: loint stiffness-its characterization and significance. Biomed Eng 4:8, Wright V, johns R: Quantitative and qualitative analysis of joint stiffness in normal subjects and in patients with connective tissue diseases. Ann Rheum Dis 20:36, Volume 16 Number I July 1992 JOSPT