Question

I conducted and EMG lab to compare peak voltages in modified and standard pushups. Looking at the data table I can't decipher where the up-phase occurs versus the down phase. Would it be during the spike increase or decrease for the up-phase?

Selected Signals ORT BICEPS BR, UV 2500T 2000 1500 1. ORTLAT TRICEPS UV 2500 2000- 1000 COD 10 20 1040 GO 090100110 120 130 140

Answer 1

The pushup is a simple exercise that can strengthen and tone many of the muscles of the upper body and core. There are many variations of pushup that suit a range of abilities and focus on different sets of muscles.The modified pushup is for people who want a more challenging exercise than the wall pushup but are not quite ready for a standard pushup.This pushup, focus on tightening all the muscles to maintain a stiff, straight body.The Muscles worked are arms, shoulders, chest, and serratus anterior.The standard pushup requires more work than the modified pushup because it does not involve using the knees to help support the body weight.The Muscles worked are same.

The following shows where the up phases occur versus down phase:

Glenohumeral Joint Action DOWN phase

Glenohumeral Joint Action UP phase   

Scapulothoracic Joint Action: DOWN phase

Action potentials in neurons are also known as "nerve impulses" or "spikes.Muscles in pain have upward spikes close together showing continuous contraction of muscle without much space in between. Nerve conduction that is slow shows spikes, but they do not have much height and linger on a plateau, indicating numbness or nerve damage.

Scapulothoracic Joint Action: UP phase

Elbow Joint Action: DOWN phase

Elbow Joint Action: UP phase  

Glenohumeral Muscles: DOWN phase   

Glenohumeral Muscles: UP phase   

Scapulothoracic Muscles: DOWN phase   

Scapulothoracic Muscles: UP phase   

Elbow Muscles:   DOWN phase

Push Up: Elbow Muscles: UP phase

Muscle tissue normally shows no EMG activity when at rest or when moved passively by the examiner. When the patient actively contracts the muscle, spikes (motor unit action potentials) should appear on the recording screen, reflecting the electrical activity within. Decreases in the amplitude and duration of spikes are associated with muscle diseases, which also show faster recruitment of other muscle fibers to compensate for weakness. Recruitment is reduced in nerve disorders.Therefore  the spike increase or decrease for the up-phase depends on the patient.