Effectiveness of instrument assisted soft tissue mobilization (IASTM) and muscle energy technique (MET) on post-operative elbow stiffness: a randomized clinical trial

ABSTRACT

Background

Stiffness is a common complication following trauma and surgeries around the elbow, which can result in upper limb functional disabilities. Soft tissue mobilization techniques such as Instrument-assisted Soft Tissue Mobilization (IASTM) and Muscle Energy Technique (MET) have limited evidence in elbow rehabilitation. This study aimed to compare their effects on postoperative elbow stiffness.

Methodology

26 subjects were recruited (13 each group) with postoperative elbow stiffness (minimum 6 weeks post surgery) and randomly allocated in two groups: IASTM and MET. Pain [Numeric Pain Rating Scale NPRS)], ROM (Goniometer), and Function [Disability of Arm, Shoulder and Hand (DASH) and Patient-Specific Functional Scale (PSFS)] were assessed at baseline and post-intervention.

Results

The data of 26 subjects were analyzed and both groups significantly improved in outcome scores post-intervention. The improvements in ROM and function between groups were comparable, but NPRS and PSFS showed greater improvement in the IASTM group (p < 0.05).

Conclusion

IASTM and MET were both effective in improving outcomes in postoperative elbow stiffness. IASTM was more effective in improving pain and patient-specific function.

Introduction

Elbow is a constrained synovial hinge joint with a normal range of motion (ROM) of 0°–145° with a functional arc of 100° for both flexion – extension (30° to 130°) and pronation – supination (50° in either direction) [1]. The elbow joint has a propensity for stiffness because of: a) complexity of joint surfaces, b) high tissue sensitivity to trauma, c) predisposition of the brachialis muscle to myositis ossificans, and d) prolonged immobilization in the presence of unstable fixation [2–8]. Additionally, trauma and postoperative healing process lead to intra-articular effusion with the joint adopting a more flexed position to maximize its capacity and minimize intra-articular pressure [4]. Several biochemical, biomechanical, and morphological changes thereafter can lead to fibrofatty proliferative changes in the connective tissues, adherence of the cartilage and synovial folds, and bone resorption leading to ligament weakening, and muscular inhibition [4,8–10]. In addition, scar tissue can restrict the blood flow, which can limit vital nutrients and oxygen perfusion to the injured area leading to pain, inhibiting full physiological recovery, and limiting function [10,11]. The “stiff elbow” is defined as loss of extension of greater than −30° and/or flexion of less than 120° [1,2,12,13]. Loss of elbow function can cause significant disability and affect activities of daily living, work-related tasks, and recreational activities. A 50% reduction of elbow range of motion (ROM) can result in 80% reduction of upper extremity function [2].

Postoperative elbow rehabilitation is often an arduous task involving many therapists’ supervised sessions with limited options of modalities and exercise interventions. Moreover, the added demands of occupation and sports or recreation need to be considered for complete recovery [3]. Various conservative interventions such as therapeutic exercises, stretching, strengthening exercises, continuous passive motion, electrotherapeutic modalities along with static progressive orthosis, and functional activities are employed for elbow ROM restoration when administered within a 6-month duration [14–16]. Existing literature, however, shows a paucity of evidence on the use of manual therapy techniques in postsurgical elbow rehabilitation [14–17].

Muscle Energy Technique (MET) is defined as a manual therapy technique, which uses muscle’s own energy to produce isometric contraction in a precisely controlled manner and direction, against which a counterforce is applied by a manual therapist. MET helps stimulate proprioceptors and mechanoreceptors to reduce pain (pain gate mechanism) and also incorporates the Golgi tendon reflex to reduce muscle spasm to lengthen shortened muscle and regain mobility. It also helps reduce tissue edema and retrain the stabilizing function of the muscles [18–24]. A systematic review recommended MET as an effective technique in treating various musculoskeletal conditions [20]. However, there is very limited evidence of its efficacy in postoperative rehabilitation [20]. Parmar et al (2011) found the beneficial effects of MET (isolytic contraction) on pain and knee ROM following hip surgery [24]. A study done by Faqih et al (2019) found that MET was safe and effective to improve pain, ROM, and function in patients with early post-surgical elbow [8].

Instrument-assisted soft tissue mobilization (IASTM) has also recently emerged as a popular manual therapy technique and is a skilled intervention that includes the use of specialized tools to manipulate the skin, myofascial muscles, and tendons by various direct compressive stroke techniques [25]. IASTM facilitates the healing process through increased fibroblast proliferation and increased collagen synthesis, maturation, and alignment. The instrument used in the IASTM allows deeper penetration and more focused treatment, while also reducing imposed stress on the therapist hands [24]. Recent evidence supports the use of IASTM in reducing pain and soft tissue restriction, improving ROM, and function [25–33].

There is a need to explore emerging newer techniques in manual and soft tissue mobilization for their effectiveness in postoperative rehabilitation along with evidence for specific guidelines with defined optimal parameters [15,16]. Thus, the current study aimed to compare the MET and IASTM for their effectiveness on pain, elbow ROM, and function in patients with postoperative elbow stiffness.

Methodology

This single-blinded two-group randomized trial was cleared by the Institutional Ethical Committee (IEC-SIOR/Agenda059) and registered with the Clinical Trials Registry of India (CTRI/2020/12/029976). The study was conducted from January 2020 to October 2021 (21 months) in an outpatient physiotherapy set-up of an orthopedic hospital. Women and men with the age >18 years and having elbow postoperative stiffness with loss of extension of ≥–30 degrees and/or flexion ≤120 degrees were included if they were at least 6-week post-surgery with open reduction and internal fixation done for either of the following fractures: extra-articular or intra-articular fractures of distal end humerus, and/or proximal radius, and/or proximal ulna. All subjects were informed of the purpose of the study along with risks and benefits and recruited after obtaining written consent. The subjects were excluded if they declined consent or had pathological fractures, associated ipsilateral injuries, bilateral upper extremity injuries, neuro-vascular disorders, heterotrophic ossification, and contraindications for IASTM (as per the IASTM guidelines).

The sample size was calculated using G* power version 3.1.9.4 with the effect size of 1.6 at α error ≤0.05, Power (1-β) at 95%, two-tailed, equally allocated. Considering an attrition rate of 20%, the sample size was 26 (13 each group) [10]. The subjects recruited after screening for eligibility and consenting to participate were randomly allocated to Group A or Group B, using simple computer-generated random number allocation method. The allocation sequence (done preceding baseline assessment) was concealed for the subjects and the data analysts. Group A (n = 13) received IASTM, whereas Group B (n = 13) received MET (post-isometric relaxation) for elbow and forearm. Demographic data of each group are presented in Table 1.

Table 1.

Demographics and baseline characteristics of both the groups.

	GROUP A:IASTM (Mean ± SD)	GROUP B: MET (Mean ± SD)	p value
DEMOGRAPHICS
Age(years)	39.77± 12.73	42.38± 13.49		0.61
Sex: Male:Female	M:F-8:5	M:F-8:5		1.00
Hand Dominance: Right:Left	13	12:1		0.32
Duration Of Elbow Stiffness (weeks)	7.1±2.6	8±2.2		0.34
PAIN
NPRS-at rest	1.85±1.68	1.00±1.15		0.09
NPRS-At Activity	6.31±1.60	5.23±1.54		0.69
ROM
Flexion	106.31±11.39	106.85±15.23		0.48
Extension	-25.54±6.49	-26.85±7.90		0.73
Pronation	68±18.43	74.62±16.04		0.49
Supination	68±19.37	81.46±9.46		0.06
FUNCTION
DASH	56.41±21.04	50.24±25.09		0.7
PSFS	2.46±1.60	3.27±2.02		0.3
TYPES OF FRACTURE
Distal end Humerus	3		4
Proximal end Radius	4		4
Proximal end Ulna	2		2
Proximal end Radius and Ulna	1		1
Combination of all 3 bones	3		2

*p < 0.05 indicates significant difference between groups.

NPRS- Numerical Pain Rating Scale; DASH-Disability of Arm, Shoulder and Hand; PSFS- Patient-Specific Functional Scale.

Outcome measures

Assessment of the demographic details and all outcome measures for pain, ROM, and function was done at baseline and post-intervention by the same blinded assessor with postgraduate qualification in musculoskeletal physiotherapy and a clinical experience of 5 years. (1) Pain was assessed by Numeric Pain Rating Scale (NPRS), (Reliability – ICC −0.95, validity −0.87) a 11-point numerical scale (in cm) ranging from 0 (no pain at all) to 10 (worst imaginable); subjects were asked to circle the number on the scale that fit best to their pain intensity [34] (2) ROM of the elbow joint and forearm was measured using the universal half goniometer (Reliability-ICC-0.53–0.97.) Positions used to measure elbow flexion-extension were in supine position, whereas the forearm pronation-supination was done in sitting position [35,36] (3) Function was assessed by the Disability of arm shoulder and hand (DASH) (Reliability- ICC- 0.96; validity- 0.70), which is a 30-item patient-reported questionnaire, which can rate difficulty and interference with function on a 5-point Likert scale used to evaluate impairments, activity limitations, as well as participation restrictions in both leisure activities and work due to elbow dysfunction, regardless of which arm is affected. The scores for all items are then summed up to a scale score, where higher scores indicate higher disability [37–40]. (4) Patient-specific functional scale (PSFS) is a self- reported (Reliability -ICC- 0.84, validity − 0.5–0.74), patient-specific outcome measure, designed to assess functional changes specific to individuals’ needs. Subjects were asked to enumerate and rate any three activities that were difficult or were unable to perform due to their elbow affection, on an 11-point numerical scale (in cm). The subjects were asked to mark a number between 0 and 10 (0 = inability to perform activity, 10 = able to perform at prior level) [41]. Total score was summed up and divided by the number of activities to calculate the averaged score.

Intervention

After baseline assessment, both groups received 3 weeks of supervised intervention, twice a week, for a total of six sessions. The intervention therapists were not blinded for the treatment procedures.

Group A received IASTM treatment, which was given by the “Edge tool”, that is an ergonomically designed stainless steel instrument and offers several different hand holds, eliminating operator fatigue [42]. Prior to the treatment, the IASTM therapeutic effects were explained. The scanning assessment was done to identify areas of restrictions directed by the gritty sensations using the Edge tool. Each restriction was treated with the tool for 30–60 sec and given by a certified IASTM intervention therapist with postgraduate qualification in musculoskeletal physiotherapy and 8 years of clinical experience. The application of pressure with the tool, on involved regions, was guided by the subject’s tolerance, using NPRS where the subject was asked to verbalize the response to the applied pressure. The NPRS score had to be less that 5/10 to avoid unnecessary discomfort [11,22,26,27].

Group B received MET post-isometric relaxation technique with an isometric hold of 7–10 sec with 20% maximum voluntary contraction (MVC) followed by relaxation and a gentle passive stretch taking the joint to a new end ROM. Each restricted movement of the elbow and forearm – flexion, extension, forearm supination, and pronation – were administered with 2 sets of 3–4 contractions each [8,18,19] The intervention was performed by a therapist with postgraduate qualification in musculoskeletal physiotherapy and a clinical experience of 5 years.

Conventional treatment given to both groups included warm up with active ROM exercises for the wrist, elbow, and shoulder (5–10 min), gentle passive stretching with 30 sec hold for three repetitions, progressive low load strengthening exercises (for all major muscle groups of the upper limb), and closed kinetic chain activities [43–46]. Subjects were asked to report for any adverse effect. The subjects received home exercise protocol, which consisted of active, active-assisted ROM exercises, and low load strengthening for the upper limb, and were encouraged to use the upper limb for light activities of daily living. After 3 weeks of intervention, the subjects were reassessed for the outcome measures by the same blinded assessor.

Statistical analysis

All statistical analyses were done using Statistical Package for the Social Sciences (SPSS v26.0) software with an alpha level set at 0.05. All outcome measures were tested for normal distribution using Shapiro-Wilk test. The outcomes of NPRS at rest were not normally distributed (p < 0.05), whereas NPRS on activity, ROM, DASH, and PSFS were normally distributed (p > 0.05). The matching of the baseline characteristics of both groups was analyzed pre-intervention using unpaired t-test for parametric data and Mann-Whitney U-test for non-parametric data and both groups were found to be matched at baseline (Table 1). Within group analysis was done using the paired t-test (ROM) and Wilcoxon-Signed Rank test (NRPS, DASH, and PSFS), whereas between group comparisons were done using the unpaired t-test (ROM) and the Mann-Whitney U-test (NPRS and DASH). Statistical tests were two-tailed and the p-value <0.05 was considered significant. Effect size was calculated according to Cohen’s criteria, where 0.1–0.3; 0.4–0.6; >0.7 indicated small, medium, and large effects, respectively [47].

Results

45 subjects were screened for eligibility with 19 excluded for the following reasons: 16 did not meet the inclusion criteria, {3 had revision surgery, 4 had ligament and nerve injury, 2 had heterotrophic ossification, 5 had more elbow mobility (than that specified in the inclusion criteria), 2 had associated injuries} and 3 declined to participate. The 26 subjects recruited were randomly allocated into two groups, which were Group A with IASTM and Group B with MET. A total of three subjects were lost to follow-up: 1 from group A failed to comply due to personal reasons and 2 from group B withdrew due to unrelated health reasons. No adverse response was reported in either of the treatment techniques groups. Data of the 26 subjects (Group A = 13; Group B = 13) were analyzed using intention to treat analysis as data of 11.5% subjects were lost to follow-up. (Consort Flow)

CONSORT 2010 flow diagram.

Demographic data of age, gender, hand dominance, type of fracture, and matched baseline clinical characteristics of both groups are demonstrated in Table 1.

Results of within-group comparisons displayed significant improvements in both groups for all measured variables, whereas between groups, IASTM showed significant differences in pain and PSFS with comparable results seen in ROM and DASH represented in Tables 2 and Table 3.

Table 2.

Change in outcome measure scores in both groups after the respective intervention.

	IASTM (Mean ± SD)					MET (Mean ± SD)
	PRE	POST	p value	Effect Size Cohen’s d)		PRE	POST	p value	Effect Size (Cohen’s d)
	PAIN
NPRS At Rest	1.85 ± 1.68	0.15 ± 0.38	0.01*	1.39		1.00 ± 1.15	0.44 ± 0.44	0.015*	0.64
NPRS On Activity	6.31 ± 1.60	2.31 ± 1.55	0.01*	2.5		5.23 ± 1.54	2.69 ± 1.49	0.001*	1.67
	Range Of Motion (ROM) (in degrees)
Flexion	106.31 ± 11.39	127.39 ± 9.01	<.001*	2.48		106.85 ± 15.23	121.76 ± 12.45	<.001*	1.83
Extension	−25.54 ± 6.49	−7.71 ± 6.37	<.001*	2.74		−26.85 ± 7.90	−11.31 ± 7.73	<.001*	2.37
Pronation	68.00 ± 18.43	78.67 ± 14.54	<.001*	1.39		74.62 ± 16.04	81.23 ± 10.18	.004*	0.99
Supination	68.00 ± 19.37	79.67 ± 13.24	<.001*	1.46		81.46 ± 9.46	87.92 ± 3.23	.005*	0.95
	FUNCTION
DASH	56.41 ± 21.04	26.45 ± 14.81	0.001*	1.64	50.24 ± 25.09		23.43 ± 13.58	0.001*	1.32
PSFS	2.46 ± 1.60	6.27 ± 2.00	0.001*	2.10	3.27 ± 2.02		5.25 ± 3.09	0.010*	0.76

*p < 0.05 indicates significant difference between groups.

Abbreviations: NPRS- Numerical Pain Rating Scale; DASH-Disability of Arm, Shoulder and Hand; PSFS- Patient-Specific Functional Scale.

Table 3.

Between group differences of the mean difference of variables for both groups after the respective interventions.

	GROUP A: IASTM (Mean ± SD)	GROUP B: MET(Mean ± SD)	p value	Effect size
PAIN
NPRS-At Rest	1.69 ± 1.49	0.77 ± 0.83	0.106	-
NPRS-At Activity	4.00 ± 1.29	0.78 ± 0.78	0.002*	0.8
ROM
Flexion	21.08 ± 8.48	14.91 ± 8.14	0.998	-
Extension	−17.83 ± 6.50	−15.54 ± 6.55	0.847	-
Pronation	10.67 ± 7.65	6.62 ± 6.63	0.696	-
Supination	11.67 ± 7.96	6.46 ± 6.78	0.501	-
FUNCTION
DASH	29.96 ± 10.11	26.81 ± 16.10	0.545	-
PSFS	3.81 ± 1.68	1.99 ± 2.31	0.006*	0.4

*p < 0.05 indicates significant difference between groups.

Abbreviations: NPRS- Numerical Pain Rating Scale; DASH-Disability of Arm, Shoulder and Hand; PSFS- Patient-Specific Functional Scale.

Pain

A significant improvement was noted for the mean difference scores of resting pain on the NPRS in the IASTM group (NPRS at rest, mean difference = 1.69 ± 1.49, p = 0.01) and the MET group (NPRS at rest, mean difference score = 0.77 ± 0.83, p = 0.015) and the groups demonstrated moderate-to-large effect sizes (ES = 0.64–1.39). However, when comparing between group differences in resting pain, statistical significance was not reached (p = 0.106) with both groups showing similar improvements in resting pain. Both groups also showed significant improvements in within group mean difference scores of NPRS on activity for IASTM (NPRS on activity, mean difference = 4.00 ± 1.29, p = 0.01) and the MET group (NPRS on activity, mean difference score = 0.78 ± 0.78, p = 0.64) with large effect size (ES = 2.5–1.67). When comparing between group differences in pain on activity, the IASTM group showed significant improvement (p = 0.002) with a large effect size (ES = 0.8).

ROM

The mean change in the flexion ROM in IASTM group and MET group was 21.08 ± 8.48 and 14.91 ± 8.14; for extension −17.83 ± 6.50 and −15.54 ± 6.55; for pronation 10.67 ± 7.65 and 6.62 ± 6.63 and supination 11.67 ± 7.96 and 6.46 ± 6.78, respectively. However, the between groups comparison was insignificant (p > .05) as there was a wide range of standard deviations in both groups.

Function

1. DASH: With a MCID value of 10.83, the DASH showed comparable and significant improvement (0.545) within both groups with mean change of 29.96 ± 10.11 and 26.81 ± 16.10 in IASTM and the MET group, respectively [48].

2. PSFS: The MCID for PSFS is between 2.0 and 3.0, which is graded as follows: 0.8-small change, 3.2-medium change, 4.3-large change [36,40,49,50]. The PSFS improved in both groups, but the values significantly improved in the IASTM group with a mean change of 3.81 ± 1.68 compared to the MET with a mean change of 1.99 ± 2.31 (p = 0.006) with a medium effect size (ES = 0.4).

Discussion

The current study compared the effectiveness of IASTM and MET on pain, ROM, and function in subjects with post-operative elbow stiffness. We found both groups having comparable effects in improving ROM and function; however, IASTM was more effective in reducing pain and improving patient-specific functional scores. There were no reported adverse events due to use of MET or IASTM during the trial making both techniques safe to implement (by a trained therapist) after 6 weeks of surgery.

Effect on pain

Both groups showed significant reduction in post-activity pain scores following intervention. IASTM showed a significant improvement in NPRS on activity score with a large effect size compared to MET. Reduction in pain in the MET group can be explained by previous RCTs, which suggest that simultaneous stretching and isometric contraction stimulate the muscle and joint proprioceptors and mechanoreceptors resulting in peripheral pain modulation (pain gate mechanism) [51,52]. Hypoalgesia is also hypothesized to be mediated from central mechanisms of stimulating periaqueductal gray in the midbrain or non-opioid serotonergic and noradrenergic descending inhibitory pathways [22]. Studies suggested that the rhythmic muscle contraction during MET leads to increased intercapillary blood and lymph flow reducing the pro-inflammatory cytokines and altering the interstitial pressure, which leads to desensitizing the peripheral nociceptors [22].

Improvement in pain by IASTM could be explained through peripheral pain modulation (pain gate) along with reduction in muscle tone and increased skin temperature and blood flow following the maneuver. Furthermore, activation of the inter-fascial mechanoreceptors alter the proprioceptive inputs to the central nervous system and contribute to pain relief [53–55]. Efficacy of IASTM in reducing pain has been documented in lateral epicondylitis [55], non-specific low back and neck pain [56], as well as shoulder impingement [57,58].

Faquih et al found MET improved pain scores (measured by VAS), in postoperative subjects with elbow stiffness, with better improvement (p = 0.05) in subjects who were treated earlier (mean change of 5.61) than the other group who were treated a week later (mean change of 4.35). The current study has also found improvements in both pain at rest and pain on activity in both groups; with pain on activity showing greater improvements (above the MCID) with larger effect size. Between groups comparison showed the IASTM group was more effective than MET in reducing pain on activity (with large effect size), but failed to be significant for comparison of resting pain. This could be explained by the fact that most subjects (in both groups) were a minimum of 6 weeks post-surgery and had very low baseline values for rest pain as the acute postoperative inflammation and pain was resolved; with most subjects having pain during and post activity rather than at rest. Also the lack of normal distribution in the scores of NPRS at rest along with the smaller baseline values (IASTM: 1.85 ± 1.68; MET: 1.00 ± 1.15) produced insignificant results for between group comparisons.

Effect on ROM

Baseline ROM measurements showed greater restriction in the ROM of flexion, extension, followed by pronation, supination. Post-intervention, both groups showed comparable results in improving elbow ROM (even after considering the 10 degree error for goniometer measurements of elbow ROM) [16]. Faqih et al carried out an experiment with one group receiving MET at 3 weeks and the other group a week later (at 4 weeks postoperative). The subjects received the intervention (6 days per week for 3 weeks), which included post isometric relaxation and/or reciprocal inhibition (8–10 repetitions of 20 % of maximal muscle contraction of 5–7 s hold) followed by a gentle passive stretch. They found significant improvement in ROM, in the group which received early MET [8]. The present study observed the effects of MET on subjects who were minimum 6 weeks post-surgery with established elbow stiffness compared to the early postoperative subjects of Faqih et al [10].

There are few studies that explored the use of tools for postoperative rehabilitation. Chughtai et al (2015) found that IASTM is effective in improving ROM, mobility and function in 23 patients with postoperative knee stiffness following total knee arthroplasty. They used Augmented Soft Tissue Mobilization(Astym), which was given over a mean of 2 months (ranging from 6 days to 5 months) and they found 89% of the treated knees had significant improvement in ROM and function [33]. Davies et al (2016) found significant improvements (p < 0.01) in function, ROM of shoulder flexion, abduction with Astym, which was given twice a week over the period of 4–6 weeks following mastectomy [59].

Joint ROM is influenced by many factors such as pain along with stiffness in joint capsule, ligaments and elongation of muscle tendon units across the joint. The creep and plastic changes in connective tissues due to MET allow the joint to stretch into new ranges [22]. The mechanical (viscoelastic changes) and neurophysiologic changes (inhibitory Golgi tendon reflex) contribute to increase in muscle length and increase in extensibility thereby increasing ROM [56].

The results of IASTM in improving ROM could be explained by the mechanical pressure exerted by the tool, which has a direct effect on myofascial restrictions (identified by the instrument while scanning the restricted tissues by gritting and pain in that particular area) [26]. The more focused treatment applied by the tool avoids the overstretching of surrounding normal tissues (which can be caused by the generalized conventional stretching). IASTM also leads to localized controlled inflammation, which leads to increased local temperature and blood flow, reabsorption of excessive fibrosis and realignment of collagen fibers. These changes result in a decrease in sliding resistance between muscle and deep fascia [5861⁶⁰61⁶¹,]. In the current study, the intervention therapist found more restrictions around the scar, musculotendinous junctions of pectorals, bicipital groove, brachioradialis, intermuscular septa, and interosseous membrane.

Effect on function

Decrease in pain and improvement in ROM in both groups could be the contributing factor for improvement in function. Overall, observed responses of subjects in the DASH score suggested that dressing, grooming, overhead activities such as placing an object on a shelf, and recreational activities which need free arm movement as well as some force through arm, shoulder, and hand were more limited. The PSFS had subjects picking out other activities as most affected due to the restricted mobility and postoperative elbow stiffness:- washing, cleaning their face, eating, lifting weight, and few more occupation-specific activities. Its patient-specific nature is relevant to the individual subject and may include activities that are missed in self-reported outcome measure. PSFS was also useful in identifying IASTM having clinically important and significant change in score when compared with MET. The improvements in function with MET and IASTM were comparable with the other studies mentioned above.

The effects of conventional treatment cannot be overlooked in the present study and could have also contributed in improving mobility, enhancing stability at elbow as well as proximal and distal joints. Active and active-assisted ROM exercises, progressive resistance exercises, and closed kinetic chain activities were incorporated in the supervised sessions as well as home exercises, which were common to subjects of both groups [13,17,43,44]. The absence of a control group with only the conventional treatment was a limitation of the present study.

There were other limitations including the influence of the method of fracture fixation, soft tissue repair, occupation, and perceived compliance that were not considered and could have impacted the outcomes [16]. Future studies can consider a more homogeneous cohort with long-term follow-ups. Combined effect of IASTM and MET can also be analyzed for additional benefits.

Conclusion

IASTM and MET are both effective in improving pain, ROM, and function in postoperative elbow stiffness. IASTM has more advantages in improving pain and patient-specific functional score as compared to MET, and can be safely administered as an effective adjunct in post-surgery elbow rehabilitation. Long-term follow-up for retention of the results can be studied in the future.

Funding Statement

The author(s) reported there is no funding associated with the work featured in this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10669817.2022.2122372