Feature Article

Toe-Touch Weight Bearing: Myth or Reality?

Guy Rubin, MD; Oded Monder, DPT; Rinat Zohar, BPT; Ann Oster, DPT; Ofra Konra, DPT; Nimrod Rozen, MD, PhD

  • Orthopedics
  • October 2010 - Volume 33 · Issue 10:
  • DOI:

Abstract

Toe-touch weight bearing and partial weight bearing are commonly prescribed orders. The purpose of this study is to evaluate the validity of toe-touch weight bearing and partial weight bearing regimens.

Twenty-five orthopedic surgeons participated in the study. They were asked to answer a questionnaire regarding toe-touch weight bearing and partial weight bearing definitions, and were asked to bear weight partially according to the accepted definitions of each order. Weight bearing on the affected limb was measured by the SmartStep System (Andante Medical Devices, Ltd, Omer, Israel).

There was a 40% success rate for toe-touch weight bearing as measured by kilograms and 58% as measured by percentage of body weight. There was a 22% success rate for partial weight bearing as measured by kilograms and 50% success rate as measured by percentage of body weight. For toe-touch weight bearing as measured by kilograms, 52% exerted a mean 15.9 kg more than the maximum. For partial weight bearing as measured by kilograms, 64% exerted too much weight with an average of 14.2 kg more than the maximum. There was a significantly higher success rate for the percentage of body weight order than the kilogram order. The partial weight bearing order with the percent body weight order had a lower mean deviation from desired performance. This study and others demonstrate the need for standardization of weight bearing orders.

Toe-touch weigh bearing or touch down weight bearing is a commonly prescribed order aimed to reduce the pressure on muscles supporting the affected hip, allowing the ground to act as the leg support. Toe-touch weight bearing is directed following acetabular fracture fixation, plate fixation of displaced and unstable fractures of the proximal and distal third of the tibia, plate fixation of the articular surface of the distal tibia, and following hip dislocation.1,2 The definition of toe-touch weight bearing is ill-defined in the literature with Rüdi et al2 defining toe-touch weight bearing as weigh bearing of 10 to 15 kg and Hershko et al3 defining it as up to 20% of body weight.

Partial weight bearing is used during fracture rehabilitation, following osteotomies, and after autologous chondrocyte implantation,4 amputations, or arthroplasties of lower extremities.5,6 The definition of partial weight bearing encompasses a wide range with many practicing clinicians considering partial weight bearing ranging from anything greater than non-weight bearing, but less than full weight bearing.7 Most of the authors use definitions of partial weight bearing ranging from 30% to 50% of body weight4,9 or 20 to 25 kg.2

The ability of either a healthy or ill patient to achieve partial weight bearing is questionable and is widely examined with or without training.3,5-19 The methods used to educate and assess this skill have included the therapist’s hand8 force platform,8,9 bathroom scales,17,18 insole pressure measuring devices,3,5,20 and limb load monitors21 with various kinds of feedback.

The purpose of this study is to evaluate the validity of the toe-touch weight bearing and partial weight bearing regimens.

We addressed 6 questions:

  1. What is the doctors’ knowledge level of the definition of toe-touch weight bearing and partial weight bearing?
  2. Is there a difference in the ability to perform toe-touch weight bearing or partial weight bearing using walker or a forearm crutch?
  3. What are the overall performance success rates for each order?
  4. What is the mean weight deviation when there is performance failure?
  5. Which regimens (toe-touch weight bearing/partial weight bearing) give the best performance success rate and the least weight deviation?
  6. What is the best way to define the order, by body weight percentage or by absolute kilogram?

Materials and Methods

Subjects

Twenty-five healthy, male orthopedic surgeons participated in the study. They were required to complete a questionnaire regarding to the definition of toe-touch weight bearing and partial weight bearing. They were also asked to walk for 20 meters with either a walker or a forearm crutch and partially bear weight according the definition for toe-touch weight bearing (10-15 kg or up to 20% of body weight) and partial weight bearing (20-25 kg or 30%-50% of body weight). Training was standardized in that only verbal instructions and verbal feedback were given during performance, without the use of other training methods or equipment (eg, a bathroom scale or feedback device).

Measurement Tools

Weight bearing on the affected limb was measured by the SmartStep System (Andante Medical Devices, Ltd, Omer, Israel), which was found to be valid and reliable in relation to the force plate.22 The SmartStep is a portable gait analysis and biofeedback system. The device is made of a force-sensing insole connected to 2 pressure sensors that measure the force applied under the heel and forefoot of the affected limb. The data is received and analyzed by a control unit, which is worn around the ankle. Data is transmitted to a computer running the software, which graphically displays an analysis of the patient’s gait data, including body weight bearing, gait pattern, and temporal parameters including velocity, cadence, and timing of gait. The foot–shoe force reaction can be measured in absolute value (kg/pound) or normalized to body weight (%). The entire foot force graph, showing the overall weight on the foot, is calculated by finding the maximum value (hindfoot+forefoot) at a set point during a stride. The value as shown statistically represents the average peak value for the entire foot.

Statistical Methods

Paired t tests were used to assess whether the doctor’s performance using the walker and crutches differed within each order (PBW, toe-touch weight bearing) and order definition (number of kilograms, percentage of body weight) classification. Pearson correlation was used to assess the association between the weight exerted on the leg when performing the toe-touch weight bearing and partial weight bearing order. As there was no difference in performance between the walker and crutches, performance using each of these instruments was considered a repeated measure of the same order. The McNemar-Bowker test was used to test for symmetry between the doctors’ performances as measured by kg or % body weight.

Results

A total of 25 doctors participated in the study. The mean weight of the doctors was 87.9 kg (SD, 16.2 kg; median, 82 kg) and the mean age 45 years (SD, 10.7 years; median, 42 years).

The answers to the questions we addressed are as follows:

1. What is the doctors’ knowledge level of the definition of toe-touch weight bearing and partial weight bearing?

Fifteen doctors (60%) were able to provide the correct partial weight bearing definition while only 6 doctors (24%) were able to correctly provide the toe-touch weight bearing definition. These 6 doctors used the correct definition for both methods. There was a statistically significant difference in the ability to define the measures (McNemar test: P,.004).

2. Is there a difference in the ability to perform toe-touch weight bearing or partial weight bearing using walker or a forearm crutch?

The weight applied to the leg did not differ significantly between the use of the walker and the use of the crutches (Table). There was a statistically significant correlation between the walker’s and crutches’ performance (kilogram and percentage of weight) for partial weight bearing (kilograms: r=.70, P<.001; percentage of weight: r=.55, P<.004) and for the toe-touch weight bearing order (kilograms: r=.40, P<.05; % weight: r=.42, P<.04).

Table: Mean (Median) Toe Touch and PWB Performance by Type of Instrument

3. What are the overall performance success rates for each regimen?

As there was no statistically significant difference in performance between the walker and the crutches, we considered them as 2 repeated measures within each regimen.

Toe-touch weight bearing performance rate. There was a 40% success rate for toe-touch weight bearing as measured by kilograms and 58% as measured by body weight percentage. Six of the 25 doctors (24%) successfully performed the toe-touch weight bearing order twice while 11 (44%) failed twice, when performance was measured as the number of kilograms desired. Eleven of the 25 doctors (44%) successfully performed the toe-touch weight bearing order twice while 7 (28%) failed twice when performance was measured as the desired body weight percentage (Figure 1).

Figure 1: TTWB success rate according to order type
Figure 1: TTWB success rate according to order type.

Partial weight bearing performance. There was a 22% success rate for partial weight bearing as measured by kg and 50% success rate as measured by body weight percentage. One of the 25 doctors (4%) successfully performed the partial weight bearing order twice while 15 (60%) failed twice when performance was measured as the number of kg desired. Eight of the 25 doctors (32%) successfully performed the partial weight bearing order twice while 8 (32%) failed twice when performance was measured as the desired body weight percentage (Figure 2).

Figure 2: Partial weight bearing success rate according to order type
Figure 2: Partial weight bearing success rate according to order type.

4. What is the mean weight deviation when there is a performance failure?

Toe-touch weight bearing. For the kilogram regimen, 7 (28%) of the 25 doctors exerted a mean of 3.6 kg (SD=3.4) below the 10 kg required, while 13 (52%) exerted a mean 15.9 kg (SD=12.5) above the maximum of 15 kg.

For the body weight percentage regimen, none of the 25 doctors (0%) exerted insufficient body weight (for the order was 0%-20% body weight); however, 5 (25%) exerted no weight (0 kg). Fourteen (56%) exerted excessive body weight with an average of 13.4 kg (SD=11.9) more than the 20% of body weight permitted.

Partial weight bearing. For the kilogram order, 4 (16%) of the 25 doctors exerted insufficient weight with an average of 1.7 kg (SD=4.7) below the minimum 20 kg required. Sixteen of the 25 doctors (64%) exerted excessive weight with an average of 14.2 kg (SD=14.1) above the maximum of 25 kg required.

For the body weight percentage regimen, 13 of the 25 doctors (52%) exerted insufficient weight with an average of 4.7 kg (SD=4.3) below the 30% of body weight required. Five of the 25 doctors (20%) exerted excessive weight with an average of 7.4 kg (SD=9.1 kg) above the maximum 50% of body weight.

5. Which regimen (toe-touch weight bearing/partial weight bearing) gives the best performance success rate and the least weight deviation?

Performance success rate (Figure 3). Kilogram definition: There was no statistically significant difference in the success rate between toe-touch weight bearing and partial weight bearing performance (McNemar-Bowker test: P>.23) although 11 doctors had a greater number of successes on the toe touch task than the partial weight bearing task and 4 had a greater number of successes with the partial weight bearing task.

Figure 3: Comparative success rate by definition type
Figure 3: Comparative success rate by definition type.

Body weight percentage definition: There was no statistically significant difference in the success rate between toe-touch weight bearing and partial weight bearing performance (McNemar-Bowker test: P>.43); 13 doctors had a greater number of successes on the toe touch task than the partial weight bearing task whereas 8 had a greater number of successes with the partial weight bearing task.

Absolute deviation for each regimen. The mean deviation of the toe-touch weight bearing regimen is not statistically significantly different from the mean deviation of the partial weight bearing order (toe-touch weight bearing: 7.2±12.9 vs partial weight bearing: 9.1±13.3 kg, P>.36).

6. What is the best way to define the regimen, by body weight percentage or by absolute kilogram?

Performance success. For the toe touch order, there was a tendency for greater success with the body weight percentage regimen (McNemar-Bowker test: P<.07), with 7 doctors (28%) performing more proficiently using the body weight percentage definition than the kilogram regimen. The remainder of the doctors performed equally well with both of the definitions.

For the partial weight bearing order, there was a tendency for greater success with the body weight percentage regimen (McNemar-Bowker test: P<.10), with 12 doctors (48%) performing better using the body weight percentage definition than the kilogram regimen and 3 (12%) performing better using the kilogram regimen.

For overall regimen type (4 trials per doctor), there was a significantly higher success rate for the body weight percentage regimen than the kilogram regimen (McNemar-Bowker test: P<.02) with 18 doctors having a higher success rate for the body weight percentage regimen, 5 having the same success rate, and 2 having a higher success rate for the kilogram regimen.

Absolute deviation for each regimen. Paired t tests showed that the kilogram or body weight percentage regimen definition were similar in the deviation from desired performance of the toe-touch weight bearing regimen (kilogram deviation: 7.2±12.9 vs percentage of body weight: 7.5±11.1, P>.71), but the partial weight bearing regimen with the body weight percentage regimen had a lower mean deviation from desired performance (kilograms: 9.1 vs percentage of body weight: -1.0 kg, P<.001).

Discussion

Based on current evidence, it seems that the amount of weight bearing has clinical consequences,23-27 therefore, it is important for certain patients to partially weight bear. Nevertheless, there is no clinical or laboratory evidence regarding the difference in the amount of weight bearing on the outcome. As a result, the literature does not apply the definition of toe-touch weight bearing, and the definition of partial weight bearing is broad. This lack of consensus reflects in our study when 60% of the doctors provided the partial weight bearing definition while only 24% were able to provide the toe-touch weight bearing definition.

Clark et al28 demonstrated that, during walking with assistive devices, muscle activation patterns varied with weight-bearing load. The leg extensor muscles appeared to incur a greater reduction in muscle activity when compared with their flexor counterparts. Additionally, the walker and axillary crutch differed with respect to their muscle activity levels and weight-bearing characteristics. Our study demonstrated that the weight applied to the leg did not differ significantly between the use of the walker or crutches in healthy individuals.

Reviewing the literature regarding studies evaluating the validity of the partial weight bearing regimen, we found that patients performed an overload of up to 50% or more than the target weight prescribed, needed more time to reach the target level, with any retained learning diminishing rapidly, and the individuals were unreliable in following weight bearing restrictions.5-12,14,16-21 Our study demonstrated a poor success rate for each regimen with a high weight deviation from the target prescribed. We also demonstrated that the regimen prescribed in the individual’s body weight percentage is more likely to give a better success rate and a lower weight deviation from the target weight prescribed especially for partial weight bearing regimen.

Chow et al11 reported that among factors influencing the ability to partially weight bear, muscle power and mental state are the most significant. Other factors such as age, body weight, and type of surgery do not seem to have any effect. Trauma or surgery may temporarily decrease muscle power that may compromise a patient’s ability to partially weight bear.11,12 Koval et al29 evaluated the efficacy of the “bear weight as tolerated” order in patients following hip fracture surgery. They demonstrated that the amount of weight exerted on the operated limb constantly increased with time and those patients with osteosynthesis of a fracture exerted less weight compared to patients following hemiarthroplasty. They concluded that patients who are allowed to bear weight as tolerated after treatment for a femoral neck or intertrochanteric fracture appear to voluntarily limit loading the injured limb.

This study and others demonstrate the need for standardization of weight bearing orders. Randomized control trials are required to evaluate the difference in outcome for each regimen and for different amounts of weight applied by the patient. We, therefore, suggest using the “weight bearing as tolerated” regimen or prescribing the regimens according to body weight percentage.

References

  1. Rockwood CA, Green DP, Bucholz RW, Ovid Technologies I. Rockwood and Green’s Fractures in Adults. 6th ed. Philadelphia, PA: Lippincott, Williams, & Wilkins; 2006.
  2. Ruedi TP, Buckley RE, Moran CG. AO Principles of Fracture Management. New York, NY: Thieme; 2007.
  3. Hershko E, Tauber C, Carmeli E. Biofeedback versus physiotherapy in patients with partial weight-bearing. Am J Orthop. 2008; 37(5):E92-E96.
  4. Gillogly SD, Voight M, Blackburn T. Treatment of articular cartilage defects of the knee with autologous chondrocyte implantation. J Orthop Sports Phys Ther. 1998; 28(4):241-251.
  5. Tveit M, Karrholm J. Low effectiveness of prescribed partial weight bearing. Continuous recording of vertical loads using a new pressure-sensitive insole. J Rehabil Med. 2001; 33(1):42-46.
  6. Vasarhelyi A, Baumert T, Fritsch C, Hopfenmuller W, Gradl G, Mittlmeier T. Partial weight bearing after surgery for fractures of the lower extremity—is it achievable? Gait Posture. 2006; 23(1):99-105.
  7. Ebert JR, Ackland TR, Lloyd DG, Wood DJ. Accuracy of partial weight bearing after autologous chondrocyte implantation. Arch Phys Med Rehabil. 2008; 89(8):1528-1534.
  8. Gray FB, Gray C, McClanahan JW. Assessing the accuracy of partial weight-bearing instruction. Am J Orthop. 1998; 27(8):558-560.
  9. Bohannon RW, Waters G, Cooper J. Perception of unilateral lower extremity weightbearing during bilateral upright stance. Percept Mot Skills. 1989; 69(3 Pt 1):875-880.
  10. Bohannon RW, Kelly CB. Accuracy of weightbearing at three target levels during bilateral upright stance in patients with neuropathic feet and control subjects. Percept Mot Skills. 1991; 72(1):19-24.
  11. Chow SP, Cheng CL, Hui PW, Pun WK, Ng C. Partial weight bearing after operations for hip fractures in elderly patients. J R Coll Surg Edinb. 1992; 37(4):261-262.
  12. Dabke HV, Gupta SK, Holt CA, O’Callaghan P, Dent CM. How accurate is partial weightbearing? Clin Orthop Relat Res. 2004; (421):282-286.
  13. Duda GN, Bartmeyer B, Sporrer S, Taylor WR, Raschke M, Haas NP. Does partial weight bearing unload a healing bone in external ring fixation? Langenbecks Arch Surg. 2003; 388(5):298-304.
  14. Li S, Armstrong CW, Cipriani D. Three-point gait crutch walking: variability in ground reaction force during weight bearing. Arch Phys Med Rehabil. 2001; 82(1):86-92.
  15. Malviya A, Richards J, Jones RK, Udwadia A, Doyle J. Reproducibilty of partial weight bearing. Injury. 2005; 36(4):556-559.
  16. Pataky Z, De Leon RD, Golay A, Assal M, Assal JP, Hauert CA. Biofeedback training for partial weight bearing in patients after total hip arthroplasty. Arch Phys Med Rehabil. 2009; 90(8):1435-1438.
  17. Schaefer L, Bohannon RW. Perception of unilateral weightbearing during unilateral and bilateral upright stance. Percept Mot Skills. 1990; 71(1):123-128.
  18. Warren CG, Lehmann JF. Training procedures and biofeedback methods to achieve controlled partial weight bearing: an assessment. Arch Phys Med Rehabil. 1975; 56(10):449-455.
  19. Winstein CJ, Pohl PS, Cardinale C, Green A, Scholtz L, Waters CS. Learning a partial-weight-bearing skill: effectiveness of two forms of feedback. Phys Ther. 1996; 76(9):985-993.
  20. Perren T, Matter P. Feedback-controlled weight bearing following osteosynthesis of the lower extremity. Swiss Surg. 1996; 2(6):252-258.
  21. Gapsis JJ, Grabois M, Borrell RM, Menken SA, Kelly M. Limb load monitor: evaluation of a sensory feedback device for controlled weight bearing. Arch Phys Med Rehabil. 1982; 63(1):38-41.
  22. Isakov E. Gait rehabilitation: a new biofeedback device for monitoring and enhancing weight-bearing over the affected lower limb. Eura Medicophys. 2007; 43(1):21-26.
  23. Augat P, Merk J, Ignatius A, et al. Early, full weightbearing with flexible fixation delays fracture healing. Clin Orthop Relat Res. 1996; (328):194-202.
  24. Kenwright J, Goodship AE. Controlled mechanical stimulation in the treatment of tibial fractures. Clin Orthop Relat Res. 1989; (241):36-47.
  25. Kenwright J, Gardner T. Mechanical influences on tibial fracture healing. Clin Orthop Relat Res. 1998; (355 Suppl):S179-S190.
  26. Kershaw CJ, Cunningham JL, Kenwright J. Tibial external fixation, weight bearing, and fracture movement. Clin Orthop Relat Res. 1993; (293):28-36.
  27. Sarmiento A, McKellop HA, Llinas A, et al. Effect of loading and fracture motions on diaphyseal tibial fractures. J Orthop Res. 1996; 14(1):80-84.
  28. Clark BC, Manini TM, Ordway NR, Ploutz-Snyder LL. Leg muscle activity during walking with assistive devices at varying levels of weight bearing. Arch Phys Med Rehabil. 2004; 85(9):1555-1560.
  29. Koval KJ, Sala DA, Kummer FJ, Zuckerman JD. Postoperative weight-bearing after a fracture of the femoral neck or an intertrochanteric fracture. J Bone Joint Surg Am. 1998; 80(3):352-356.

Authors

Drs Rubin, Monder, Oster, Konra, and Rozen and Ms Zohar are from the Orthopedic Department, Ha’Emek Medical Center, Afula, and Dr Rozen is also Faculty of Medicine at Technion, Haifa, Israel.

Drs Rubin, Monder, Oster, Konra, and Rozen and Ms Zohar have no relevant financial relationships to disclose.

The authors thank Paula Herer for statistical analysis and Frances N.J. Nachmani and Georget Nemirovsky for assistance in manuscript preparation.

Correspondence should be addressed to: Guy Rubin, MD, Orthopedic Department, Ha’Emek Medical Center, Afula 18101, Israel (guytalr@ bezeqint.net).

doi: 10.3928/01477447-20100826-02

doi:

Healio is intended for health care provider use and all comments will be posted at the discretion of the editors. We reserve the right not to post any comments with unsolicited information about medical devices or other products. At no time will Healio be used for medical advice to patients.