Schwartz ppt Article Discussion Relationship Between Two Measures

Schwartz ppt Article Discussion Relationship Between Two Measures of Upper Extremity Strength: Manual Muscle Test Compared to Hand-Held Myometry Schwartz et al. , Arch Phys Med Rehabil, 1992

Introduction • Muscle strength is quantified in clinical practice, most often by MMT or Hand-Held Myometry methods (tools) of measurement • This research explored the relationship between measures on patients with spinal cord injury (SCI)

Introduction MMT measurements Advantages: • Accepted across medical professions; inexpensive; convenient, quantitative Disadvantages Requires extensive training Questionable reliability, especially between examiners Measurements influenced by examiner experience and bias Subjectivity, especially when scoring grades of strength ≥ 4 Bias related to pt (sex, age, occupation)

Introduction Hand-Held Myometry measurements Advantages • Quantitative; simple to perform; potential of improved reliability both between examiners and between oneself, limits bias related to pt Disadvantages Cost and availability Lack of standardization procedures Tester strength

Purpose (objectives) 1. Determine the relationship between MMT and Myometry measurements of strength 2. Define the range of Myometry measurements that best correlate with MMT grades (scores) of muscle strength 3. Determine which of the measures best captures the change (recovery) in muscle strength following SCI

Methods Design Prospective cohort Longitudinal Repeated measures Testing performed by physicians and trained technicians At 72 hrs, 1 wk, 2 wks, and 1, 2, 3, 4, 6, 12, 18, 24 months post injury Muscle test: Right & Left biceps brachii (elbow flexors); Right & Left extensor carpi radialis (wrist extensors) Participants N=122 SCI (Frankel Grades A thru D) at levels C 4, C 5 or C 6

Comparison of Measurements MMT methods (strength grades) Myometer (with digital output)

Strength Testing MMT: 10 -point scale based on accepted testing standards Myometer: Displays force up to 30 kg, output recorded over 2 sec. contraction Biceps: Two positions as appropriate (gravity eliminated / *against gravity? ) Resistance placed on the volar surface of the wrist joint ECR: One position Resistance placed against the dorsal surface of the metacarpals

Data Analysis Spearman correlations (r-value) MMT & myometry measurements ANOVA (Analysis of Variance) (p-value) Difference between levels of myometry scores grouped according to MMT grades Linear regression (line equation) Comparison of MMT to myometry across recovery

Results Table 1. Myometry measures are correlated to MMT scores in patients receiving therapy following SCI Table 2. Myometry correspond with MMT scores of less than 4; (variability in myometry data increases as strength increases) Table 3 and Figs 1 -4. Myometry detected increase in strength associated with recovery over time, not so with MMT grading

CORRELATION Note high r values and significant results (P ≤. 001) for 22 of 24 comparisons Only the 2 comparison in box are not correlated (L/R biceps at 12 months) The measures were all correlated, except when testing the biceps at 12 months

ANOVA Table shows increasing mean Myometry values correspond with increasing MMT scores It is important to note that variability in mean data increases as strength increases Can myometry value be translated to MMT score? Mostly, the exception found in this column of the table

LINEAR REGRESSION L BICEPS Which measure best captures Y= 8. 37 +. 018 X the recovery in strength over during the recovery period Slope of line-of-best-fit indicates improvement strength over time Slope of myometry data =. 018 Slope of MMT data =. 001 Y= 4. 75 +. 001 x

Key Points Objective 1: Two methods are correlated, mostly Myometry more specific to subtle change Objective 2: Both methods measuring change = good MMT has a ceiling effect in 4+ strength Healthy = healthy Objective 3: Backs up results from 1 and 2; both measure change, MMT better ≤ 3. 5/5 Myometry more specific to change, makes sense

Discussion Well designed study Large sample size Multiple time points Established reliability of measures prior to study Strength tested on a population of patients that had a wide-range of strength deficits What else? Limitations Results apply to these participants, and likely, only these muscles Examiners were not blinded What else?

Relevance to Clinical Practice MMT is a reliable and valid measure of muscle strength, especially at grades < 4 MMT scores ≥ 4 are not sensitive enough to detect increases (or decreases) in strength over time Discuss how these results might influence your practice

Dynamometry Clinical Assessment: 6280 Discussion

What is it? “Myometry” “Dynamometry” Objective measure Measuring force production Different than EMG, how? NOT measuring Torque http: //lafayetteevaluation. com/products/lafayette-hand-held-dynamometer

How to test? Resistance force MUST be perpendicular to segment Tester must apply force to: “make” or “break” a test Advantages • • Portable Expense (compared to Biodex) Simplicity Objective (continuous variable vs. MMT categorical) • Patient buy-in • Intra-rater reliability • Inter-rater reliability? Disadvantages • • • Inter-rater reliability? Standardized procedures? Tester ability Perpendicular force Useful in certain populations (spasticity) • Expense (compared to MMT)

Final word Consider advantages vs. disadvantages Consider target muscles/actions Standardization Practice, practice! https: //tensnet. com/products/microfet 2 -mmt? variant=12568544936041&utm_source=google&utm_medium=cpc&adpos=1 o 3&scid=scplp 12 -0279&sc_intid=120279&gclid=EAIa. IQob. Ch. MI 56 C 7 u 8 PR 5 QIVWg. Oz. AB 2 mb. AXh. EAYYAy. ABEg. J 99 PD_Bw. E

Grip Strength Clinical Assessment: 6280 Discussion

What is it? “Myometry” “Dynamometry” Objective measure Measuring force production NOT measuring Torque https: //www. alimed. com/dynamometers-12410. html? pid=56576&gclid=EAIa. IQob. Ch. MI 47 WDw. MTR 5 QIVrv_j. Bx 0 rh. Ais. EAQYASABEg. L 4 bv. D_Bw. E

How does it work? Spring loaded system Voltage changes Pneumatic systems Units depends of system Pounds Kilograms Volts https: //www. topendsports. com/testing/tests/handgrip. htm

Final word Consider advantages vs. disadvantages Objective measurement Live feedback to patients