Effectiveness of a Bed Positioning Program for Treating Older Adults With Knee Contractures Who Are Institutionalized.

Many residents of nursing homes and other long-term care facilities are immobile and lack voluntary movement, often as a result of a neurological insult. Residents often cannot move their extremities or roll themselves over in bed and are dependent on their caregivers for bathing, feeding, moving about in bed, and getting into chairs. This problem may be magnified by the presence of contractures. Contractures are associated with impaired ambulation,[1, 2] pain,[1] decreased functional status,[3] pressure ulcers,[4, 5] and institutionalization.[3] For the caregivers, the presence of contractures can mean that there is an increased burden in caring for their patients. More time and effort are required to move a patient's extremities during activities such as positioning, bathing, feeding, and moving into a chair. Knee flexion contractures are one of the most prevalent types of contracture[3] and can affect bed and chair positioning, which ultimately affects a patient's quality of life.

A contracture may be defined as an increased resistance to passive stretch of a muscle resulting from fibrosis of the muscles or joints or from disorders of the muscle fiber.[6] The development of contractures may be caused by a combination of factors, including shortening of ligaments and joint capsule, intra-articular adhesions, proliferation of fibro-fatty tissues into joints, and muscular shortening.[7] The prevalence of contractures among people in nursing homes and other long-term care institutions in the United States is between 24% and 75%,[1-3] and there are approximately 1.5 million people in nursing homes in the United States.[8] The mean length of a nursing home stay is almost 3 times as long for residents with contractures as for those without contractures.[2]

In response to a constant, low loading over an extended period of time, connective tissue elongates[9,10] and shows anatomical, biochemical, and physiological changes.[11] Only 2 studies, both randomized controlled trials, were found where low-load, prolonged stretching was examined as an intervention for treating nursing home residents with knee flexion contractures.[12,13] Mean passive range of knee extension increased by 18 degrees in participants in one study,[12] whereas the intervention was ineffective in the other study.[13] Researchers in another study of 35 patients receiving long-term care evaluated a passive range of motion exercise program for treatment of contractures and found no treatment effects.[14] Evaluation of interventions for treating institutionalized, older adults with contractures is not adequately addressed in the literature.

This study was designed to evaluate the effectiveness of a bed positioning program (BPP) based on the principle of low-load, prolonged stretching to treat older adults with knee flexion contractures in a chronic care hospital. The BPP consisted of extending a patient's contracted knee and securing and maintaining that position. Although BPPs are considered standard practice by physical therapists and occupational therapists for treatment of people with contractures, it is not known whether this intervention is effective. We hypothesized that a BPP would result in an increase in passive knee extension, a decreased level of knee pain, and an improvement in skin integrity of the lower extremities. Range of knee extension is the measure used most often to determine the effectiveness of a BPP[15] and has been shown to increase after a low-load, prolonged stretch.[16] Pain and skin breakdown have been associated with contractures.[1,2,4] If BPPs are effective in treating institutionalized, older adults with knee flexion contractures, this finding would provide the rationale to continue these programs in this setting and to promote their use in other long-term care settings.

Method

Study Participants

Study participants were recruited from St Peter's Hospital, a 284-bed, chronic care hospital in Hamilton, Ontario, Canada, that provides care for older adults. Entry into the study required that participants be inpatients with no plans for discharge in the next 6 months, that they have a knee flexion contracture of 10 degrees or greater in at least one lower extremity, and that they be able to tolerate a BPP and ongoing assessments without severe pain as demonstrated by intense vocalizations or facial grimacing. Participants were excluded from the study if they demonstrated any behaviors such as agitation that prevented adherence to the program and if they were receiving the medication baclofen at the time of recruitment (baclofen is an antispasmodic that may decrease resistance to passive movement).

The physical therapists and occupational therapists at St Peter's Hospital identified eligible participants. Patients or their substitute decision makers (ie, individuals authorized to give or refuse consent to a treatment on behalf of individuals who are incapable of giving consent) were approached by the research coordinator to obtain their informed consent for participation in the study.

Study Design

A randomized 2-period crossover design was used (Fig. 1). The study participants were randomly assigned to 2 groups by a random numbers table. Group A received an 8-week period of a BPP followed by an 8-week period of no intervention. Group B received the intervention in the reverse order. There was no period to allow the patient's clinical condition to revert to something close to its initial state because we believed the periods were long enough to allow range of motion to return to baseline during the period of no intervention. We decided to recruit all patients at the start of the study instead of in a staggered fashion and to not replace dropouts because we believed it was unlikely that newly admitted patients would have contractures.

[Figure 1 ILLUSTRATION OMITTED]

Intervention

A standardized protocol for a BPP for treating people with knee flexion contractures was developed based on the results of a survey of therapists who practice BPPs[15] (Appendix). The BPP consisted of a low-load prolonged stretch performed with the participant in the supine position. Most of the patients who receive BPPs are unable to lie prone. The study participant's knee was extended as much as possible and then maintained by positioning foam rolls,(*) foam wedges,(*) or pillows under the knee(s) and then strapping a bedsheet over the extended knee(s) and securing it under the mattress. The participant's physical therapist and occupational therapist were responsible for setting up the BPP and deciding on the type of positioning equipment. The type of equipment usually required depends on the severity of the contracture, the number of extremities stretched, and the degree of muscle tone. In the study, the physical therapist assistants or occupational therapist assistants were responsible for carrying out the intervention.

Participants received a stretch of 40 minutes, 4 times a week. The dosage of the BPP was determined based on our belief of what is standard clinical practice and from a study demonstrating a treatment effect after a period of 30 minutes.[16] The dosage of a BPP is limited by the needs of the patient, including bathing, dressing, and feeding and by therapy resources. If both knees had contractures, they were stretched simultaneously for a period of 40 minutes, 4 times per week.

Four steps were taken to ensure the specified dosage and quality of the intervention. First, a diagram of how the BPP was to be conducted was placed on the inside of the participant's locker for reference by the therapist or therapist assistant. Second, therapist assistants were asked to notify the participant's therapist if there was a problem with the implementation of the intervention. Third, therapists were asked to monitor and record once a week whether the BPP was implemented correctly. Fourth, the assistants recorded the number of minutes the participant had spent on the BPP per day, adverse effects of the program, and other therapeutic interventions the participant was receiving for the lower extremities.

Data Collection

At the start of the study, therapists collected information on age, gender, primary diagnosis, and whether analgesics were prescribed. Each participant's cognitive status and functional status were assessed by his or her occupational therapist and physical therapist, respectively. Cognitive status was assessed by administering the Mini Mental State Exam (MMSE),[17] a cognitive test scored out of 30. Functional status was assessed using subsections on locomotion and transfers of the Functional Independence Measure (FIM).[18] The participant's therapist also recorded whether the patient was receiving a BPP for treatment of a knee flexion contracture prior to the start of the study. Study participants and dropouts are described and compared in Tables 1 and 2. Participants and dropouts appeared to be similar. Both groups had a high level of cognitive and physical impairment.

Table 1. Description of Participants and Dropouts for Sex, Primary Diagnosis, Analgesic Use, Functional Status, and Bed Positioning Program (BPP) Variables

                                        No. of         No. of
                                     Participants     Dropouts
                                        (n=12)          (n=4)

Sex
  Women                                    9              1
  Men                                      3              3
  Total                                   12              4

Primary diagnosis
  Stroke                                   5              2
  Dementia                                 3              2
  Parkinson disease                        2              0
  Myocardial infarction                    1              0
  Osteoarthritis                           1              0
  Total                                   12              4

Analgesic use                Yes          11              4

Mechanical lift(a)           Yes          12              4

Ambulation                   Yes           0              0

BBP on both lower
  extremities?(b)            Yes           6              2

Already on BBP?(c)           Yes           4              2

(a) Mechanical lift used for transfers from bed to chair.

(b) Receiving BPP on both knees.

(c) Receiving BBP for knee contracture before the start of the study.

Table 2. Description of Participants and Dropouts for Age, Cognitive and Functional Status, and Baseline Knee Extension

                             Participants (n= 12)

                             [bar]X      Range

Age (y)                      82          71-93
MMSE(a) (0-30)                6.00        0-25
FIM(b) transfer (1-7)         1.00        1-1
FIM locomotion (1-7)          1.00        1-1
Baseline passive knee
  extention ([degrees])     -43       -13 to -90

                             Dropouts (n=4)

                             [bar]X        Range

Age (y)                      83            73-91
MMSE(a) (0-30)                4.75          0-19
FIM(b) transfer (1-7)         1.00          1-1
FIM locomotion (1-7)          1.00          1-1
Baseline passive knee
  extention ([degrees])     -32         -12 to -53

(a) Mini Mental Status Exam.[17]

(b) Functional Independence Measure[18] (1 =total assistance required, 7=complete independence).

A single rater blinded to the intervention assessed the participants once a week for the duration of the study for knee pain and passive range of knee extension of the contracted extremity. The rater followed a standardized assessment protocol. She received protocol training by the principal investigator (PF) on 5 patients for 5 hours. The rater was an occupational therapist who had practiced clinically for 16 years, 9 of which were spent practicing in a chronic care hospital. A trained assistant (a high school student who was doing a placement at the hospital and receiving a credit for her placement) assisted the rater in positioning participants for their assessment. The rater was provided with information about each participant's communication difficulties and conditions such as osteoporosis that could have indicated that some added precautions were needed. Information was posted above the patient's bed indicating to the rater the leg(s) to be assessed.

Strategies designed to ensure that the rater remained unaware of each participant's group assignment included having a rater who did not work in the hospital at the time of the study, scheduling the rater's assessment at a different time than the BPP, having the assistants remove positioning equipment each time from the participant's room, and storing the diagram and recording forms in the participant's locker. In addition, hospital staff involved in the study were asked not to discuss the participant's status with the rater. The rater was asked to report to the investigators if she became aware of a participant's group assignment during the study. The rater was not aware of the study design or the study hypothesis.

The primary outcome measure was passive range of knee extension, which was measured using a 30.48-cm (12-in) plastic goniometer with a 360-degree scale.([dagger]) This outcome measure has been shown to have high intrarater reliability in other studies of adults with no known impairment (r=.87,[19] intraclass correlation coefficient [ICC]=.98[20]). Three measurements of passive knee extension were taken by the rater at each assessment. The mean of the 3 measurements was used in the analysis. Secondary outcome measures were the level of pain and the degree of skin breakdown.

Most pain scales rely on self-report, and no validated pain scales for patients with cognitive impairments could be found in the literature. Pain was rated by the rater while she extended and flexed the participant's hip and knee. Participants were scored on the amount of time during which they exhibited 3 pain behaviors: (1) crying or moaning, (2) facial expression, and (3) withdrawing to touch. The 3 pain behaviors have been identified by caregivers as useful pain indicators in long-term care facilities.[21] The 3 rating scales went from "none of the time," rated as 1, to "all of the time," rated as 7. The scores of the 3 behaviors were averaged for the analysis as an index of pain on passive movement related to the knee contracture.

Skin breakdown was graded by registered nurses once a week to classify the degree of tissue damage observed. A scale ranging from stage I, described as nonblanchable erythema of intact skin, to stage IV, described as full-thickness skin loss with extensive destruction, tissue necrosis, or damage to muscle, bone, or supporting structures, was used.[22]

Although the outcome measures were not directly tested on the patients in the study institution before the start of the study, a single rater was used to reduce measurement error. Test-retest reliability was "almost perfect"[23] for the primary outcome measure, passive range of knee extension (ICC=.97), and for pain (ICC=.92). Although one of the goals of a BPP is to reduce the caregiver burden in terms of decreased effort and time in providing care for these patients, an appropriate measure could not be found. Thus, caregiver burden related to the contracture was not measured.

Data Analysis

Frequency tables were computed for the categorical variables of sex, primary diagnosis, and whether analgesics were prescribed. For the continuous variables of age, MMSE scores, and FIM transfer and locomotion scores, means, and standard deviations were computed. For the outcome measures (pain and range of knee extension), the average of the mean scores for the outcomes for weeks 7 and 8 and weeks 15 and 16 was used, as there is evidence of variation in the measurements of contractures over time unrelated to the rater.[1] In addition, if a participant received the intervention on both lower extremities, the mean of the 2 measurements was used in order to make use of all of the information collected and yet to be able to compare participants receiving the interventions on one lower extremity with participants receiving the intervention on both lower extremities. The differences between the intervention period and the no-intervention period for range of knee extension, pain, and skin breakdown were tested using paired t tests. Period effects and treatment x period interaction for the outcomes were tested using t tests, as proposed by Jones and Kenward.[24] An important clinical difference in range of knee extension is between 10 and 20 degrees improvement, as reported by 5 therapists at St Peter's Hospital who practice BPPs. A further analysis included plotting weekly individual measurements for knee extension for the 16 weeks and visually examining the graphs for trends.

In order to identify a subgroup of participants who may be more likely to demonstrate treatment effects, we correlated an improvement in range of motion and pain (change scores) with 4 other variables: age, range of motion at baseline, pain at baseline, and whether the patient was on a BPP at the start of the study. For example, we hypothesized that patients with a high level of pain at baseline would show less improvement in range of motion that those with a low level of pain at baseline. Pearson correlation coefficients were computed.[25]

Results

Study Participants

Twenty-four patients were identified as eligible participants for the study. Seventeen substitute decision makers and 1 patient provided consent. Before the study commenced, 2 participants from group A died. In order to have an equal number of participants in both groups at the start of the study, 1 participant from group B was randomly selected and transferred to group A. Sixteen patients were entered into the study. During the study, 3 participants in group A and I participant in group B died. Twelve participants completed the study (5 in group A and 7 in group B). A participant flow and follow-up diagram[26] is shown in Figure 2.

[Figure 2 ILLUSTRATION OMITTED]

Data Analysis

Study participants were to receive the intervention for 40 minutes, 4 days per week, a total of 160 minutes per week. Participants in both groups received an adequate dose of the BPP. The mean number of days per week was 3.88 days for group A and 3.76 days for group B. The mean number of minutes per week was 167 minutes for group A and 157 minutes for group B. Therapists monitored the BPPs 97% of the time, and in all cases where it was monitored, the BPP was believed to be implemented correctly. The main adverse effect of the intervention was reddening of the skin over the knees from the bedsheet. Strategies to modify these effects included placing foam between the bedsheet and the participant's knees. None of the participants received other therapeutic interventions for their lower extremities. The rater became aware of the group assignment of 3 subjects (1 in group A and 2 in group B) during the study.

In examining range of knee extension at the beginning of the study, after the intervention period, and after the no-intervention period, no participant improved greater than 10 degrees with the intervention (Tab. 3). The mean difference in participants' range of knee extension between the intervention period and the no-intervention period was about 2 degrees (P=.20) (Tab. 4). We did not demonstrate a change in knee flexion contractures with a BPP. The mean change in range of knee extension was within measurement error.[19] There were no period effects or treatment x period interaction effects for range of knee extension. A period effect is when the response to treatment is different in period 1 than in period 2. An example of a treatment x period interaction effect is when the response to the treatment is different in period 1 as compared with period 2, whereas the response to no treatment shows no such difference between periods.

Table 3. Range of Knee Extension (in Degrees) at Baseline, After No-Intervention Period, and After Intervention Period for Each Participant (n=12)(a)

                                          After No-       After
Participant   Intervention   Baseline   Intervention   Intervention
No.              Period       (0 wk)       Period         Period

 1                  1           -58          -67            -60
 2                  2           -19          -17            -13
 3                  1           -56          -59            -55
 4                  2           -36          -32            -33
 5                  1           -13          -19            -19
 6                  2           -52          -57            -57
 7                  1           -43          -48            -49
 8                  2           -48          -51            -58
 9                  2           -36          -38            -31
10                  1           -39          -41            -35
11                  2           -39          -39            -39
12                  2           -77          -73            -73

(a) Range of motion is the average of weeks 7 and 8 or weeks 15 and 16 after no intervention and after intervention. If both lower extremities received a bed positioning program, then the average of the right and left knees was used for each week.

There was no difference in pain scores between the intervention period and the no-intervention period (Tab. 4). There were no period effects or treatment x period interaction for pain. One participant had skin breakdown on the lower extremities and pelvis at the baseline measurement. Three participants at 8 weeks and no participants at 16 weeks had skin breakdown on their lower extremities and pelvis. There were not enough episodes of skin breakdown to warrant an analysis of the data. There were no correlations between baseline measurements and mean change scores of the outcome measures (Tab. 5).

Table 4. Mean Difference Between the End of the Intervention Period and the End of the No-Intervention Period for Range of Knee Extension and Pain (n=12)

                                    95% Confidence     Minimum
                        Mean           Interval        Change
                    Difference(a)   Lower    Upper      Score

Knee extension(b)       1.64        -0.98     4.26      -6.99
Pain(c)                -0.23        -0.82     0.37      -2.50

                     Maximum
                     Change
                      Score       t        p

Knee extension(b)     7.17       1.38     .20
Pain(c)               0.83      -0.85     .42

(a) Mean in intervention period -- mean in no-intervention period.

(b) Change (in degrees) of range of knee extension.

(c) Change in pain score, where 1=none of the time and 7=all of the time.

Table 5. Correlation of Baseline Measures and Change Scores of Outcome Measures

                                Knee
                                ROM(a)        Pain
                      Age       (Baseline)    (Baseline)

Knee ROM            .12         .05           -.36
  (change score)    (P=.71)     (P=.87)       (P=.25)
Pain                .47         .34           -.57
  (change score)    (P=.13)     (P=.28)       (P=.06)

(a) ROM=range of motion.

Individual participants' weekly range of motion of knee extension was plotted. Although an increase in range of motion during the intervention period and a decrease in range of motion during the no-intervention period might have been expected, visual inspection of the individual participants' graphs for the primary outcome measure (knee extension) over the 16 weeks revealed no discernible trends. A graph of the mean range of knee extension for the intervention period and the no-intervention period shows that the 2 periods were similar (Fig. 3).

[Figure 3 ILLUSTRATION OMITTED]

Discussion and Conclusions

Our study does not support the use of a BPP for treating institutionalized, older adults with knee flexion contractures. Because there was no treatment effect, increasing the sample size (ie, to avoid a possible Type II statistical error) would not have increased the ability to detect an effect. A sample size of 14 was required to detect a treatment effect, and 12 participants completed the study. The test-retest reliability of the knee extension measurements was high in our study. Therefore, we believe that measurement error cannot explain the lack of a treatment effect. Even when individual scores are examined, not one participant demonstrated what we would consider clinical improvement in range of knee extension during the intervention period. There were also no treatment effects for the secondary measure of pain, which provides further evidence that the BPP is not effective. In 2 other studies of nursing home residents, there was no report of changes in pain or skin integrity.[12, 13] Our study is compared with these 2 studies of nursing home residents[12,13] in Table 6.

Table 6. Comparison of 3 Studies That Used Low-Load, Prolonged Stretch to Treat Institutionalized, Older Adults With Knee Flexion Contractures

Author, year         Light et              Steffen
 of publication        al,[12] 1984          et al,13 1995

No. of patients      11                    18
  in analysis

Type of facility     Nursing home          Nursing home

Inclusion criteria   Contracture of at     Contracture of
                      least 30 [degrees]     at least
                                             10 [degrees]

Design               Randomized            Randomized
                      controlled trial       controlled trial

Dosage               1 hour, twice         3 hours, 5 days
                       daily, 5 days per     per week
                       week for 4 weeks      for 6 months

Intervention         Modified Buck's       Splint
                      skin traction

Cognitive status     Not reported          Mean=8 (no. of
                                             errors out of
                                             10)(a)

Functional status    Nonambulatory         Transfers: mean = 1

                                           Ambulation: mean= 1
                                             (1 = maximum
                                             assistance)

Baseline passive     30-132                11-79
  range of knee
  flexion
  contracture
  ([degrees])
Outcomes             Passive range of      Passive range
                       knee extension        of hip, knee,
                                             and ankle
                                             motion, knee
                                             pain, and
                                             function

Is intervention      Yes (P<.05) for       No (P>.05) for
 effective:           knee extension        all outcomes

Mean change          18                    2
  in knee
  extension
  ([degrees])

Author, year         Our study
  of publication

No. of patients      12
  in analysis

Type of facility     Chronic care hospital

Inclusion criteria   Contracture of at
                      least 10 [degrees]

Design               Randomized crossover design

Dosage               40 minutes, 4 days per week
                       for 8 weeks

Intervention         Bed positioning
                      program

Cognitive status     Mean=6 (out of 30)(b)

Functional status    Transfers (FIM(c)): mean = 1
                     Ambulation (FIM): mean = 1
                       (1 =total assistance required)

Baseline passive     13-89
  range of knee
  flexion
  contracture
  ([degrees])

Outcomes             Passive range of knee
                       extension and pain

Is intervention      No (P>.05) for
 effective:           all outcomes

Mean change          2
  in knee
  extension
  ([degrees])

(a) Short Portable Mental Status Questionnaire.

(b) Mini Mental Status Exam.[17]

(c) Functional Independent Measure.[18]

There are several plausible explanations for our negative findings. The contractures of participants may have been too long-standing and resistant to treatment, or their contractures may not have been severe enough to respond to treatment. The researchers in the other 2 studies on nursing home residents[12,13] did not report duration of contractures, but the researchers in the study with negative findings[14] reported an average length of stay in the nursing home of 3 years, with a range of 2 months to 9 years. The participants in our study spent an average of 6 years in the hospital, with a range of 1 to 15 years. We do not know whether duration of contractures is an important factor in determining the response to treatment. Severity of contractures may explain the difference in findings. The mean baseline range of knee extension of the participants in the study with positive findings[12] was -79 degrees, whereas it was -36 degrees in the study with negative findings[13] and -43 degrees in our study.

Other possible explanations for our findings may be related to the treatment. The study implementing the longest stretch[13] had negative findings (Tab. 6). Thus, we still do not know what dosage of stretch will provide the best results. The intensity of the stretch may be determined by the type of equipment. All 3 studies used different equipment to maintain a stretch. The study that used leg traction with weights hanging over the end of the bed had much better results[12] (Tab. 6).

Limitations of our study include the possibility of carry-over effects. Use of the crossover design assumes there is no carry-over effect from the intervention period to the no-intervention period. Presence of a carry-over effect can lessen the treatment effect. A period of 8 weeks was used in an attempt to minimize these effects. Another limitation of our study is the questionable ability of the BPP to maintain an intense stretch. The intensity of the stretch was not measured in our study; however, the stretch from the BPP may be substantial relative to a patient's usual resting position in bed. The type of equipment used in the BPP was selected to maintain skin integrity and to maintain adherence to the program among patients with cognitive impairment by promoting comfort.

We used a research design where participants acted as their own controls to minimize the effects of heterogeneity in the sample. Our sample included not only older adults with various diagnoses but also patients with unilateral contractures, unlike previous studies.[12,13] In addition, the intervention was standardized and appropriate for the population of interest. The high risk of morbidity and mortality and the lack of appropriate outcome measures in our study magnifies the challenges encountered in conducting research in this population. We believe that future studies should be randomized controlled trials, should include a large number of participants to allow for a high drop-out rate, should include patients with unilateral contractures, should be long enough to detect a treatment effect, and should ensure an intense stretch.

(*) Vitacare Medical Products Inc, 331 Bowes Rd, Concord, Ontario, Canada L4K 1J2.

([dagger]) JA Preston of Canada Ltd, 1224 Dundas St East #5, Mississauga, Ontario, Canada L4Y 4A2.

References

[1] Mollinger LA, Steffen TM. Knee flexion contractures in institutionalized elderly: prevalence, severity, stability, and related variables. Phys Ther. 1993;73:437-444.

[2] Souren LEM, Franssen EH, Reisberg B. Contractures and loss of function in patients with Alzheimer's disease. JAm Geriatr Soc. 1995; 43:650-655.

[3] Rabiner A, Roach KE, Spielholz N, Judson L. Characteristics of nursing home residents with contractures. Physical & Occupational Therapy in Geriatrics. 1995;13(4):1-10.

[4] Knight DB, Scott H. Contracture and pressure necrosis. Ostomy Wound Manage. 1990;26:60-62, 65-67.

[5] Butler MA. Spasticity: a consideration in rehabilitation of the elderly. Rehabilitation Nursing. May-June 1985:14-19.

[6] Yarkony GM. Prevention and management of contractures. In: Kaplan PE, ed. The Practice of Physical Medicine. Springfield, Ill: Charles C Thomas, Publisher; 1984:526-537.

[7] Binkley J. Overview of ligament and tendon structure and mechanics: implications for clinical practice. Physiotherapy Canada. 1989;41: 24-29.

[8] Lair T, Lefkowitz D. National Medical Expenditure Survey Research Findings 7: Mental Health and Functional Status in Residents of Nursing and Personal Care Homes. Rockville, Md: Agency for Health Care Policy and Research, Public Health Service; 1990. DHHS Publication No. (PHS) 90-3470.

[9] Akeson WH, Amiel D, Woo SLY. Immobility effects on synovial joints: the pathomechanics of joint contracture. Biorheology. 1980;17: 95-110.

[10] Cornwall MW. Biomechanics of noncontractile tissue: a review. Phys Ther. 1984;64:1869-1873.

[11] Gossman MR, Sahrmann SA, Rose SJ. Review of length-associated changes in muscle: experimental evidence and clinical implications. Phys Ther. 1982;62:1799-1808.

[12] Light K, Nuzik S, Personius W, Barstrom A. Low-load prolonged stretch vs. high-load brief stretch in treating knee flexion contractures. Phys Ther. 1984;64:330-333.

[13] Steffen TM, Mollinger LA. Low-load, prolonged stretch in the treatment of knee flexion contractures in nursing home residents. Phys Ther. 1995;75:886-895.

[14] Kaegi C, Lapointe M, Giroux F, Bourbonnais D. Absence of change in the passive joint movements of long-term care patients following application of a passive range of motion exercise program. Physical & Occupational Therapy in Geriatrics. 1995;13 (1/2):81-100.

[15] Fox P, Richardson J, McInnes B, Tait D. Bed positioning programs for older adults in a chronic care hospital: a survey. Physical & Occupational Therapy in Geriatrics. 1997; 15 (1) :75-89.

[16] Odeen I. Reduction of muscular hypertonus by long-term muscle stretch. Scand J Rehabil Med. 1981;13:93-99.

[17] Folstein MF, Folstein SE, McHugh PR. "Mini-mental state": a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res. 1975;12:189-198.

[18] Data Management Service for the Uniform Data System for Medical Rehabilitation. Guide for Use of the Uniform Data Set for Medical Rehabilitation. Buffalo, NY: The Buffalo General Hospital, State University of New York at Buffalo; 1987.

[19] Boone DC, Azen SP, Lin CM, et al. Reliability of goniometric measurements. Phys Ther. 1978;58:1355-1360.

[20] Watkins MA, Riddle DL, Lamb RL, Personius WJ. Reliability of goniometric measurements and visual estimates of knee range of motion obtained in a clinical setting. Phys Ther. 1991;71:90-96.

[21] Mohide EA, Byles J, Chambers LW. Use of observer-related clinical indicators of pain in the elderly. Can J Aging. 1983;2 (2) :71-78.

[22] Pressure Ulcers in Adults: Prediction and Prevention. Rockville, Md: US Department of Health and Human Services; 1992. AHCPR Publication No. 92-0047.

[23] Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977;33:159-174.

[24] Jones B, Kenward MG. Design and Analysis of Cross-Over Trials. New York, NY: Chapman & Hall; 1989.

[25] Howell DC. Statistical Methods for Psychology. 2nd ed. Boston, Mass: Duxbury Press; 1987.

[26] Begg C, Cho M, Eastwood S, et al. Improving the quality of reporting of randomized controlled trials: the CONSORT statement. JAMA. 1996;276:637-639.

Appendix.

Standardized Protocol for the Bed Positioning Program (BPP)

1. Before the BPP is implemented:

* the patient will be positioned supine

* the head of the bed will be lowered as much as possible toward a horizontal position while maintaining patient comfort

* the patient will undergo 2 passive range of motion movements of hip and knee flexion ending in a stretch of knee extension

2. The patient's knee(s) will be positioned to provide a stretch of knee flexors and will be maintained by:

* placing a pillow or soft, compressible roll under the knee to support the leg but also allowing for further knee extension. The specific apparatus will be determined by the assessing therapist.

* placing a sheet over the knee and securing the ends under either side of the mattress. If this procedure does not maintain the leg in a neutral position relative to rotation at the hip, then the sheet may be wrapped around the knee, pulling the leg into a neutral position, and both ends of the sheet will be secured under the same side of the mattress.

3. Any additional equipment used for maintaining the leg in the above-described position will be allowed and will be at the discretion of the assessing therapist. A study participant will receive the BPP for a 40-minute period, 4 times per week. The BPP will be implemented by a physical therapist assistant or an occupational therapist assistant.

P Fox, MSc, BSc(PT), is Clinical Lecturer, School of Rehabilitation Science, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada. Address all correspondence to Ms Fox at 341 Newbold Ct, Burlington, Ontario, Canada L7R 2Y5 ([e-mail]). She was Clinical Investigator, Research Department, St Peter's Hospital, Hamilton, Ontario, Canada, at the time of the study.

J Richardson, MSc, BSc(PT), is Associate Professor, School of Rehabilitation Science, Faculty of Health Sciences, McMaster University. She was Director of Research, St Peter's Hospital, at the time of the study.

B McInnes, BHScPT, is Director, Complex Continuing Care Program, St Peter's Hospital, and Clinical Lecturer, School of Rehabilitation Science, McMaster University.

D Tait, BHScOT, is Clinical Leader, Occupational Therapy, St Peter's Hospital, and Professional Associate, School of Rehabilitation Science, Faculty of Health Sciences, McMaster University.

M Bedard, MSc, is Director of Research, Lakehead Psychiatric Hospital, Thunder Bay, Ontario, Canada. He was Senior Research Associate, St Joseph's Health Care System Research Network, St Mary's General Hospital, Kitchener, Ontario, Canada, and University Institute of Social Gerontology of Quebec, Montreal, Quebec, Canada, at the time of the study.

All authors provided concept/research design, writing, and consultation (including review of manuscript before submission). Project management was provided by Ms Fox and Ms Richardson. Data analysis was provided by Ms Fox, Ms Richardson, and Ms McInnes. Institutional liaisons were provided by Ms Tait. The staff at St Peter's Hospital provided assistance in the study. The rater for the study was Nancy Kovacsik, an occupational therapist with experience in providing care for institutionalized older adults. Mr Bedard also assisted with data collection.

This study was approved by St Peter's Hospital Institutional Review Board.

This study was supported by St Peter's Hospital and by Vitacare Medical Products, who provided study equipment.

This article was submitted July 6, 1999, and was accepted January 6, 2000.